JP2009173905A - Phosphor, phosphor production method, phosphor-containing composition, and light emitting device - Google Patents

Abstract

Disclosed is a method for producing a phosphor capable of suppressing damage to the phosphor particles even if the phosphor particles have a relatively large particle diameter.
A firing process for firing a phosphor material and a softening process for softening a fired product obtained by the firing process are performed.
[Selection figure] None

Description

  The present invention relates to a phosphor, a method for producing the phosphor, a phosphor-containing composition, and a light emitting device. Specifically, the present invention relates to a phosphor, a manufacturing method thereof, and a phosphor-containing composition and a light emitting device using the phosphor.

  The phosphor is generally manufactured by a solid phase reaction method in which phosphor raw materials are mixed and the obtained raw material mixture is baked. In this solid phase reaction method, since the raw material mixture is fired at a high temperature, the obtained fired cake is often a product in which phosphor particles are hard and aggregated. For this reason, normally, a pulverization step using, for example, a ball mill, a mortar, or the like has been performed when manufacturing the phosphor. However, in this pulverization step, the surface of the phosphor particles is often damaged, and each phosphor particle often becomes indefinite, which has been one of the causes of a decrease in the light emission characteristics of the phosphor.

The following techniques are known as methods for suppressing damage to the surface of phosphor particles.
For example, in Patent Document 1, a substantially monodispersed phosphor-precursor particle is suspended in a flowing gas and fired by using a fluidized reactor device, so that it is substantially not agglomerated. It is described that monodispersed phosphorescent particles can be produced. According to this method, phosphorescent particles having a size of less than 1 micron can be produced.

Further, in Patent Document 2, for example, when manufacturing a ZnGa ₂ O ₄ : Mn phosphor, a phosphor raw material before firing is prepared by a wet precipitation method, so that firing at a low temperature is possible. It is described that the aggregation of can be suppressed.

  For example, Patent Document 3 relates to a method for producing a phosphor having an alkaline earth aluminate-based or alkaline earth silicate-based host crystal, using strontium nitrate as a phosphor raw material containing Sr, and using a raw material mixed solution Alternatively, a method is disclosed in which a suspension is formed into droplets having a desired particle diameter and then baked. This describes that a phosphor having extremely brittle properties can be obtained and easily pulverized.

JP-T-2001-526298 JP 2000-80363 A JP 2000-212556 A

The phosphor used in combination with the semiconductor light-emitting element preferably has a particle shape close to a true sphere and has a larger particle diameter than a phosphor for a conventional fluorescent lamp. This is because such a phosphor has good handleability and is excellent in light emission characteristics such as luminance.
Such phosphors can be manufactured at the laboratory level. However, if this is produced in large quantities for industrialization, the aggregates (baked cake) obtained by firing the phosphor raw material will sinter very strongly, so ordinary grinding means (mortar, ball mill, etc.) In this case, the desired phosphor could not be obtained because it could not be crushed. Moreover, even if it was able to be crushed, it was difficult to obtain a nearly spherical phosphor.

Even when the techniques described in Patent Documents 1 to 3 are applied, there are the following problems. That is, in the technique described in Patent Document 1, the flow reactor apparatus is expensive, and it is difficult to apply the method described in Patent Document 1 when manufacturing a phosphor having a large particle diameter or a phosphor having a large specific gravity. there were. Further, the technique described in Patent Document 2 has a complicated manufacturing process, and cannot be applied when a phosphor material having high solubility is used. Further, when strontium nitrate is used as in the technique described in Patent Document 3, NO _x may be generated, and a phosphor having a large particle diameter is manufactured in order to make a raw material mixture or suspension into droplets. Was difficult.

As described above, the phosphor manufacturing method described in Patent Documents 1 to 3 tries to suppress damage to the phosphor particles due to pulverization after the firing step by applying some device before or during the firing step. Therefore, none of the methods is sufficient as a method for suppressing damage to the phosphor particles.
The present invention was devised in view of the above-mentioned problems. Even if the phosphor has good handleability and excellent emission characteristics such as luminance, and even if the phosphor particle has a relatively large particle size, An object of the present invention is to provide a method for producing a phosphor capable of suppressing damage, and a phosphor-containing composition and a light-emitting device using the phosphor.

  As a result of intensive studies to solve the above problems, the present inventors have performed a softening process for softening the fired product (baked cake) obtained as a result of firing the phosphor material, so that the particle size of the phosphor particles can be reduced to some extent. It has been found that even a large phosphor can suppress phosphor particle damage. Further, the present inventors have found that the phosphor obtained by this method is less damaged and therefore has good handleability and excellent light emission characteristics such as luminance. Based on the above findings, the present inventors have completed the present invention.

That is, the gist of the present invention resides in the following (1) to (18).
(1) Proportion of particles having an alkaline earth metal element as part of the host crystal and having an orthosilicate or garnet crystal structure, and the circularity of the phosphor particles is less than 85% The phosphor is characterized in that is 4% by number or less, and the value of the 4-minute deviation of the particle diameter of the phosphor particles is 0.4 or less.
(2) The phosphor according to (1), wherein the phosphor contains 1 ppm or more of an element derived from a water-soluble flux.
(3) (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu and Ca ₃ (Sc, Mg, Na, Li
) ₂ Si ₃ O _12: characterized by being represented by the compositional formula selected from the group consisting of Ce, phosphor according to (1) or (2).
(4) The phosphor according to (1) or (2), which has a chemical composition represented by the following formula [1].
(M ^I _(1-xy) M ^II _x M ^III _y ) _α SiO _β [1]
(In the above formula [1],
M ^I represents one or more elements selected from the group consisting of Ba, Ca, Sr, Zn and Mg,
M ^II represents one or more activator elements capable of taking a divalent and trivalent valence,
M ^III represents one or more elements selected from the group consisting of Tb, Pr, Ce, Lu, La, and Gd,
x, y, α and β are respectively
0.01 <x <0.3,
0 ≦ y ≦ 0.025,
1.5 ≦ α ≦ 2.5, and
It represents a number satisfying 3.5 ≦ β ≦ 4.5. )
(5) In the formula [1], M ^I contains at least Ca, and the molar ratio of Ca when the sum of M ^I and M ^II is 2 is 0.000001 or more and 0.005 or less. The phosphor according to (4), characterized in that
(6) In the formula [1], when M ^I contains at least Ba and Sr, and the molar ratios of Ba and Sr to the whole M ^I are [Ba] and [Sr], respectively, [Ba] and [Sr] is
0.4 <{[Ba] / ([Ba] + [Sr])} ≦ 1
The phosphor according to (4) or (5), wherein:
(7) A method for producing a phosphor, comprising a firing step of firing a phosphor material and a softening step of softening a fired product obtained by the firing step.
(8) In the said baking process, the said phosphor raw material is baked in presence of a flux, The manufacturing method of the fluorescent substance as described in (7) characterized by the above-mentioned.
(9) In the softening step, (7) or (8), wherein the fired product is placed in an environment where the pressure is normal pressure or higher and steam is present for 0.5 hour or longer. The manufacturing method of fluorescent substance of description.
(10) The method for producing a phosphor according to (8) or (9), further comprising a step of firing at a temperature higher than the firing step before the firing step.
(11) The fluorescence according to any one of (7) to (10), characterized by having a pulverization step of pulverizing the fired product using a pulverizer having a mortar structure after the softening step. Body manufacturing method.
(12) A phosphor-containing composition comprising the phosphor according to any one of (1) to (6) and a liquid medium.
(13) A first light emitter and a second light emitter that emits visible light when irradiated with light from the first light emitter, and the second light emitter includes (1) to (6). One or more types of the phosphors according to any one of the above are contained as a first phosphor.
(14) The second phosphor includes at least one phosphor having a different emission peak wavelength from the first phosphor as the second phosphor, according to (13). Light-emitting device.
(15) The first light emitter has a light emission peak in a wavelength range of 420 nm to 500 nm, and the second light emitter emits light in a wavelength range of 570 nm to 780 nm as the second phosphor. The light emitting device according to (14), comprising at least one kind of phosphor having a peak.
(16) The first light emitter has a light emission peak in a wavelength range of 300 nm to 420 nm, and the second light emitter emits light in a wavelength range of 420 nm to 490 nm as the second phosphor. The light-emitting device according to (14), comprising at least one phosphor having a peak and at least one phosphor having an emission peak in a wavelength range of 570 nm to 780 nm.
(17) An image display device comprising the light-emitting device according to any one of (13) to (16).
(18) An illumination device comprising the light-emitting device according to any one of (13) to (16).

The phosphor of the present invention has good handleability and excellent emission characteristics such as luminance.
According to the method for producing a phosphor of the present invention, since the impact on the phosphor particles can be reduced, the phosphor particles can be prevented from being damaged, and a phosphor having a nearly spherical shape can be obtained. Moreover, the manufacturing method of the fluorescent substance of this invention is applicable also when manufacturing a fluorescent substance with a certain large particle size. And the fluorescent substance obtained with the manufacturing method of the fluorescent substance of this invention is usually excellent in handleability, and also is excellent in light emission characteristics, such as a brightness | luminance.
Further, the production method of the present invention is particularly suitable for industrially producing a phosphor.
The phosphor-containing composition and the light emitting device of the present invention are excellent in light emission characteristics.

Hereinafter, the present invention will be described in detail with reference to embodiments and examples, but the present invention is not limited to the embodiments and examples described below, and may be arbitrarily set within the scope of the present invention. You can change it to

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. However, the total of the elements shown in parentheses is 1 mol. For example, the composition formula “(Ba, Sr, Ca) Al ₂ O ₄ : Eu” is expressed by “BaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “CaAl ₂ O ₄ : Eu”. “Ba _1-x Sr _x Al ₂ O ₄ : Eu”, “Ba _1-x Ca _x Al ₂ O ₄ : Eu”, “Sr _1-x Ca _x Al ₂ O ₄ : Eu”, _{"Ba 1-xy Sr x Ca 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.)

  Further, the relationship between the color name and the chromaticity coordinates in this specification is all based on the JIS standard (JISZ8110 and Z8701).

[1. Method for producing phosphor]
In the phosphor manufacturing method of the present invention, at least a firing step for firing the phosphor material and a softening step for softening the fired product obtained by the firing step are performed. In general, prior to the firing step, a mixing step of preparing a raw material mixture by mixing phosphor raw materials is performed.

[1-1. Phosphor raw material]
As the phosphor raw material, a compound containing an element constituting the phosphor to be produced (hereinafter, appropriately referred to as “phosphor constituent element”) can be used. Examples thereof include oxides, hydroxides, carbonates, nitrates, sulfates, oxalates, carboxylates, halides, nitrides and the like containing phosphor constituent elements. In selecting the phosphor raw material, it is preferable to select in consideration of the reactivity to the obtained phosphor and the non-generation of NO _x , SO _x, etc. during firing. Furthermore, corresponding to each phosphor constituting element constituting the phosphor of the present invention, one kind of phosphor raw material may be used, or two or more kinds may be used in any combination and ratio.

Further, the impurities contained in each phosphor raw material of the phosphor of the present invention are not particularly limited as long as the phosphor characteristics are not adversely affected. However, with respect to Fe, Co, and Ni, those that are usually 1000 ppm or less, preferably 100 ppm, more preferably 50 ppm or less, and particularly preferably 1 ppm or less are used.
The weight median diameter of each phosphor material is usually 0.1 μm or more, preferably 0.5 μm or more, and usually 30 μm or less, preferably 20 μm or less, more preferably 10 m or less, and even more preferably 3 μm or less. Is used. For this reason, depending on the type of the phosphor material, pulverization may be performed in advance by a dry pulverizer such as a jet mill. As a result, each phosphor raw material can be uniformly dispersed in the raw material mixture, and the solid phase reactivity of the raw material mixture can be increased by increasing the surface area of the phosphor raw material, thereby suppressing the generation of impurity phases. It becomes.

For example, specific examples of phosphor raw materials containing Ba (Ba source) include BaO, Ba (OH) ₂ .8H ₂ O, BaCO ₃ , Ba (NO ₃ ) ₂ , BaSO ₄ , Ba (C ₂ O ₄ ). _{· 2H 2 O, Ba (OCOCH} 3) 2, BaCl 2 , and the like. Of these, BaCO ₃ , BaCl _{2 and the} like are preferable, and BaCO ₃ is particularly preferable from the viewpoint of handling. This is because it is stable in the air and easily decomposes by heating, so that undesired elements hardly remain and it is easy to obtain high-purity raw materials.

For example, specific examples of phosphor raw materials (Ca source) containing Ca include CaO, Ca (OH) ₂ , CaCO ₃ , Ca (NO ₃ ) ₂ .4H ₂ O, CaSO ₄ .2H ₂ O, and Ca (C ₂ O ₄ ) · H ₂ O, Ca (OCOCH ₃ ) ₂ .H ₂ O, anhydrous CaCl ₂ (however, it may be a hydrate). Of these, CaCO ₃ , anhydrous CaCl _{2 and the} like are preferable.

For example, specific examples of phosphor raw materials (Sr source) containing Sr include SrO, Sr (OH) ₂ .8H ₂ O, SrCO ₃ , Sr (NO ₃ ) ₂ , SrSO ₄ , Sr (C ₂ O ₄ ). _{· H 2 O, Sr (OCOCH} 3) 2 · 0.5H 2 O, SrCl 2 , and the like. Of these, SrCO ₃ , SrCl _{2 and the} like are preferable, and SrCO ₃ is particularly preferable. This is because the stability in the air is good, it decomposes easily by heating, it is difficult for undesired elements to remain, and it is easy to obtain high-purity raw materials.

For example, specific examples of the phosphor raw material (Zn source) containing Zn include ZnO, Zn (C ₂ O ₄ ) · 2H ₂ O, ZnSO ₄ · 7H ₂ O, and the like.

For example, specific examples of the phosphor material (Mg source) containing Mg include MgCO ₃ , MgO, MgSO ₄ , Mg (C ₂ O ₄ ) · 2H ₂ O, and the like.

For example, specific examples of the phosphor raw material (Si source) containing Si include SiO ₂ , H ₄ SiO ₄ , Si (OCOCH ₃ ) _{4 and the} like. Of these, SiO ₂ is preferable.

For example, specific examples of the phosphor material (Eu source) containing Eu include Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ , Eu ₂ (C ₂ O ₄ ) ₃ , EuCl ₂ , EuCl ₃ , Eu (NO). _{3) 3} · 6H ₂ O, and the like. Of these, Eu ₂ O ₃ , EuCl _{2 and the} like are preferable.

  For example, as specific examples of each phosphor raw material (Sm source, Tm source, and Yb source) containing Sm, Tm, and Yb, Eu is changed to Sm, Tm, and Yb in the respective compounds listed as specific examples of the Eu source. The substituted compound is mentioned.

For example, specific examples of the phosphor raw material (Mn source) containing Mn include MnO, MnO ₂ , Mn ₂ O ₃ , MnF ₂ , MnCl ₂ , MnBr ₂ , Mn (NO ₃ ) ₂ .6H ₂ O, MnCO _3. , MnCr ₂ O _{4 and the} like.

For example, specific examples of the phosphor raw material (Cr source) containing Cr include Cr ₂ O ₃ , CrF ₃ (may be a hydrate), CrCl ₃ , CrBr ₃ .6H ₂ O, Cr (NO ₃ ) ₂ · 9H ₂ O, (NH ₄ ) ₂ CrO _{4 and the} like.

For example, specific examples of phosphor raw materials (Tb source) containing Tb include Tb ₄ O ₇ , TbCl ₃ (including hydrates), TbF ₃ , Tb (NO ₃ ) ₃ .nH ₂ O, Tb _2. (SiO ₄ ) ₃ , Tb ₂ (C ₂ O ₄ ) ₃ · 10H ₂ O, and the like. Among these, Tb ₄ O ₇ , TbCl ₃ and TbF ₃ are preferable, and Tb ₄ O ₇ is more preferable. Moreover, it can also be used after co-precipitating other phosphor raw materials (for example, Eu source) and Tb source.

For example, specific examples of the phosphor raw material (Pr source) containing Pr include Pr ₂ O ₃ , PrCl ₃ , PrF ₃ , Pr (NO ₃ ) ₃ .6H ₂ O, Pr ₂ (SiO ₄ ) ₃ , Pr _2. (C ₂ O ₄ ) ₃ · 10H ₂ O and the like. Of these, Pr ₂ O ₃ , PrCl ₃ and PrF ₃ are preferable, and Pr ₂ O ₃ is more preferable.

For example, specific examples of the phosphor raw material (Ce source) containing Ce include CeO ₂ , CeCl ₃ , Ce ₂ (CO ₃ ) ₃ .5H ₂ O, CeF ₃ , Ce (NO ₃ ) ₃ · 6H ₂ O, and the like. Is mentioned. Of these, CeO ₂ and CeCl ₃ are preferable.

For example, as specific examples of phosphor raw materials (Lu source) containing Lu, Lu ₂ O ₃ , LuCl ₃ ,
LuF ₃ (may be a hydrate), Lu (NO ₃ ) ₃ (may be a hydrate), and the like. Of these, Lu ₂ O ₃ and LuCl ₃ are preferable.

For example, specific examples of a phosphor raw material (La source) containing La include La ₂ O ₃ , LaCl ₃ .7H ₂ O, La ₂ (CO ₃ ) ₃ .H ₂ O, LaF ₃ , La (NO ₃ ). ₃ · 6H ₂ O, La ₂ (SO ₄ ) _{3 and the} like. Of these, La ₂ O ₃ and LaCl ₃ .7H ₂ O are preferable.

For example, specific examples of the phosphor raw material (Gd source) containing Gd include Gd ₂ O ₃ , GdCl ₃ .6H ₂ O, Gd (NO ₃ ) ₃ · 5H ₂ O, Gd ₂ (SO ₄ ) ₃ · 8H. ₂ O, GdF _{3 and the} like. Of these, Gd ₂ O ₃ and GeCl ₃ .6H ₂ O are preferable.

For example, specific examples of the phosphor raw material (Ge source) containing Ge include GeO ₂ , Ge (OH) ₄ , Ge (OCOCH ₃ ) ₄ , GeCl _{4 and the} like. Of these, GeO _{2 and the} like are preferable.

For example, specific examples of the phosphor raw material (Ga source) containing Ga include Ga ₂ O ₃ , Ga (OH) ₃ , Ga (NO ₃ ) ₃ .nH ₂ O, Ga ₂ (SO ₄ ) ₃ , and GaCl _3. Etc.

For example, specific examples of the phosphor raw material (Al source) containing Al include Al ₂ O ₃ such as α-Al ₂ O ₃ and γ-Al ₂ O ₃ , Al (OH) ₃ , AlOOH, Al (NO ₃ ). _{3 · 9H 2 O, Al 2} (SO 4) 3, AlCl 3 and the like.

For example, specific examples of the phosphor raw material (P source) containing P include P ₂ O ₅ , Ba ₃ (PO ₄ ) ₂ , Sr ₃ (PO ₄ ) ₂ , (NH ₄ ) ₃ PO _{4 and the} like. .

For example, specific examples of the phosphor raw material (B source) containing B include B ₂ O ₃ and H ₃ BO ₃ .
In addition, you may use the raw material illustrated above, after coprecipitating as needed.

  Further, phosphor raw materials corresponding to N element, O element, halogen element, etc. are usually manufactured as phosphors as anion components of the phosphor raw materials of the respective phosphor constituting elements or as components contained in the firing atmosphere. Sometimes supplied.

[1-2. Mixing process]
After the phosphor raw materials are weighed so as to obtain the target composition, the phosphor raw materials are usually mixed to prepare a raw material mixture, and then the raw material mixture is fired at a predetermined temperature and atmosphere. At this time, it is preferable to perform the mixing sufficiently.

  Although it does not specifically limit as said mixing method, Specifically, the well-known method which was mentioned as following (A) and (B) can be used arbitrarily. As for these various conditions, for example, known conditions such as mixing and using two kinds of balls having different particle diameters in a ball mill can be appropriately selected.

  (A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., or pulverization using mortar and pestle, and mixer such as ribbon blender, V-type blender, Henschel mixer, or mortar and pestle And a dry mixing method in which the above phosphor raw materials are pulverized and mixed.

(B) Add a solvent or dispersion medium such as an alcoholic solvent such as methanol or ethanol or water to the phosphor raw material, and mix using, for example, a pulverizer, a mortar and pestle, or an evaporating dish and a stirring bar, A wet mixing method in which a solution or slurry is made and then dried by spray drying, heat drying, or natural drying.

The mixing of the phosphor raw materials may be arbitrarily selected from the above-mentioned wet type and dry type according to the physical properties of the phosphor raw materials.
In addition, when using a material that easily oxidizes and absorbs moisture, such as halide and nitride, it is preferable to fill with an inert gas such as argon gas or nitrogen gas, and to mix with a mixer in a glove box in which moisture is controlled. .
Further, when mixing is performed in the glove box, the moisture in the atmosphere is preferably 10,000 ppm or less, more preferably 1000 ppm or less, still more preferably 10 ppm or less, and particularly preferably 1 ppm or less. Further, oxygen is preferably 1% or less, more preferably 1000 ppm or less, still more preferably 100 ppm or less, and particularly preferably 10 ppm or less.

  In addition, the phosphor material may be sieved as necessary during the mixing and pulverization. In this case, various types of commercially available sieves can be used, but it is preferable to use a resin mesh such as a nylon mesh rather than a metal mesh in terms of preventing impurities from being mixed.

[1-3. Firing step]
In the firing step, a fired product is obtained by firing the obtained raw material mixture. The obtained fired product usually has the composition of the intended phosphor, but the particles are sintered into a fired cake.

(Baking container)
In the firing step, it is preferable that the phosphor material is filled in a container such as a crucible and fired at a predetermined temperature and atmosphere.
As the container, it is preferable to use a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each phosphor 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 carbide, silicon nitride, and magnesium oxide, and metals such as platinum, molybdenum, tungsten, tantalum, niobium, iridium, and rhodium. Alternatively, an alloy mainly containing them, carbon (graphite), or the like can be given. Here, the heat-resistant container made of quartz can be used for heat treatment at a relatively low temperature, that is, 1200 ° C. or less, and a preferable use temperature range is 1000 ° C. or less.
Examples of such heat-resistant containers are preferably heat-resistant containers made of alumina, platinum, molybdenum, tungsten, tantalum, and the like.

  Here, when firing in a reducing atmosphere using a metal carbonate as a phosphor raw material, firing is performed in a multi-stage firing manner so that the firing furnace is not damaged by the desorbed carbon dioxide, and primary firing is performed. It is preferable to convert at least a part into a metal oxide (described later).

  The filling rate when filling the phosphor material into the heat-resistant container (hereinafter referred to as “heat-resistant container filling rate”) varies depending on the firing conditions, but the fired product is pulverized in a post-treatment step described later. It may be filled to such an extent that it does not become difficult to perform, and is usually 10% by volume or more and usually 90% by volume or less. Further, since the phosphor material filled in the crucible has a void ratio between the particles of the phosphor material, the volume of the phosphor material per 100 ml volume filled with the phosphor material is usually 10 ml or more, Usually 90 ml or less.

Further, when it is desired to increase the amount of the phosphor raw material to be processed at a time, it is preferable that heat is uniformly circulated in the heat-resistant container, for example, by decreasing the rate of temperature rise.
Further, it is preferable that the filling rate when filling the heat-resistant container into the furnace (hereinafter, referred to as “furnace filling ratio” as appropriate) is such that the heat does not become uneven between the heat-resistant containers in the furnace.
Furthermore, in the above baking, when the number of heat-resistant containers in the baking furnace is large, for example, to make the heat transfer to each heat-resistant container uniform, such as slowing the temperature increase rate, It is preferable for firing without unevenness.

(Baking conditions)
The firing conditions such as the firing temperature, pressure, and atmosphere in the firing step are preferably set appropriately for each phosphor to be manufactured. Hereinafter, a phosphor having a chemical composition represented by the formula [1] (described later), other oxide phosphors and nitride phosphors will be described with increasing preferred ranges. However, the firing conditions are not limited to the ranges described below.

-Firing conditions of the phosphor having the chemical composition represented by the formula [1]
In the case of producing a phosphor having the chemical composition represented by the formula [1], it is preferable that a part of the phosphor is subjected to reduced pressure conditions in the temperature rising process during firing. Specifically, it is preferably at room temperature or higher, preferably 1500 ° C. or lower, more preferably 1200 ° C. or lower, and even more preferably 1000 ° C. or lower. Is usually preferably in the range of 10 ⁻² Pa or more and less than 0.1 MPa. Among them, it is preferable to introduce an inert gas or a reducing gas into the system after reducing the pressure in the system, and to raise the temperature in that state.
At this time, if necessary, the target temperature may be maintained for 1 minute or longer, preferably 5 minutes or longer, more preferably 10 minutes or longer. The holding time is usually 5 hours or less, preferably 3 hours or less, more preferably 1 hour or less.

  When the phosphor having the chemical composition represented by the formula [1] is produced, the firing temperature (maximum temperature reached) is usually 850 ° C. or higher, preferably 950 ° C. or higher, and usually 1400 ° C. or lower, preferably 1350. It is the range below ℃. If the firing temperature is too low, the crystal does not grow sufficiently and the particle size may be small. On the other hand, if the firing temperature is too high, the crystal grows too much and the particle size may become too large.

  When producing a phosphor having the chemical composition represented by the formula [1], the rate of temperature rise is usually 2 ° C./min or more, preferably 3 ° C./min or more, and usually 10 ° C./min or less, preferably 6 C / min or less. Below this range, the firing time may be longer. Moreover, when it exceeds this range, a baking apparatus, a container, etc. may be damaged.

  When producing a phosphor having the chemical composition represented by the formula [1], the pressure during firing varies depending on the firing temperature and the like, but is not particularly limited, but is usually 0.01 MPa or more, preferably 0.1 MPa or more. Moreover, it is 200 MPa or less normally, Preferably it is 100 MPa or less. Among these, industrially, it is usually about atmospheric pressure to about 0.3 MPa, and atmospheric pressure is preferable in terms of cost and labor.

  When producing a phosphor having the chemical composition represented by the formula [1], the firing time is not particularly limited because it varies depending on the temperature, pressure, etc. during firing, but usually 10 minutes or more, preferably 1 hour or more, more It is preferably 3 hours or longer, more preferably 4 hours or longer, and usually 24 hours or shorter, preferably 15 hours or shorter.

When producing a phosphor having the chemical composition represented by the formula [1], the atmosphere during firing is not particularly limited, but firing is preferably performed in an atmosphere having a low oxygen concentration. The oxygen concentration at the time of firing is usually 150 ppm or less, preferably 100 ppm or less, more preferably 50 ppm or less, still more preferably 20 ppm or less, and particularly preferably 10 ppm or less. Ideally, no oxygen is present at all. As a specific example, it is carried out in a single atmosphere or a mixed atmosphere of two or more of gases such as carbon monoxide, carbon dioxide, nitrogen, hydrogen, and argon. Among these, it is preferable to contain reducing gas, such as carbon monoxide and hydrogen, and especially under a nitrogen atmosphere containing hydrogen.

  Here, the hydrogen content contained in the hydrogen-containing nitrogen atmosphere is usually 1% by volume or more, preferably 2% by volume or more, and usually preferably 5% by volume or less, and the particularly preferable hydrogen content is 4% by volume. is there. 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 cannot be achieved.

Furthermore, when producing a phosphor having the chemical composition represented by the formula [1], the firing atmosphere is a reducing atmosphere such as a hydrogen-containing nitrogen atmosphere during firing, and solid carbon coexists in the reaction system. It is preferable that the oxygen concentration is lowered by, for example, a strong reducing atmosphere. This for producing the phosphor having a chemical composition represented by the formula [1], and selects the atmosphere required as activating element M ^II is contributing ionic state to luminescence (valence) .

For example, it is desirable that at least a part of Eu, which is one of the preferable activating elements M ^II causing green light emission, be a divalent ion. Specifically, the ratio of Eu ²⁺ in the total Eu is preferably as high as possible, and is usually 50% or more, preferably 80% or more, more preferably 90% or more, and particularly preferably 95% or more. However, a compound containing a trivalent Eu ion such as Eu ₂ O ₃ is usually used as the Eu phosphor material. Therefore, in order to obtain a phosphor that contains Eu ²⁺ that is a divalent ion and produces green light emission, carbon monoxide, hydrogen-containing nitrogen is used to reduce the trivalent ion Eu ³⁺ to the divalent ion Eu ^2+. It can also be fired in some reducing atmosphere such as hydrogen. However, even in these firing atmospheres, oxygen derived from raw materials and the like is contained, so that it is difficult to sufficiently reduce the oxygen concentration. Also, Sm as M ^II element, Tm, even when using a Yb etc., there is a problem similar to the case of the aforementioned Eu.

On the other hand, according to the study by the present inventors, when the trivalent ion of the M ^II element is reduced to the divalent ion and simultaneously introduced into the host crystal, solid carbon is coexisted in addition to the normal reducing atmosphere. It is effective to perform firing under the conditions (that is, conditions with stronger reducing power). As a result, the obtained phosphor usually has a feature that it emits light with high brightness in a wavelength range of 510 nm or more and 542 nm or less and has a narrow emission spectrum width.

Moreover, the object color of the phosphor having a chemical composition represented by the formula [1] is considered to have become an indicator of reduction degree of M ^II element. By firing under a strong reducing atmosphere, M ^II element is sufficiently reduced, the phosphor represented by the formula [1] It is believed that will have a luminous object color of a predetermined range.

The type of solid carbon is not particularly limited, and any type of solid carbon can be used. Examples thereof include carbon black, activated carbon, pitch, coke, graphite (graphite) and the like. The reason why it is preferable to use solid carbon is that oxygen in the firing atmosphere reacts with the solid carbon to generate carbon monoxide gas, and this carbon monoxide further reacts with oxygen in the firing atmosphere to form carbon dioxide. This is because the oxygen concentration in the firing atmosphere can be reduced. Among the above-mentioned examples, activated carbon having high reactivity with oxygen is preferable. The shape of the solid carbon includes powder, bead, particle, block, etc., but is not particularly limited.
In addition, solid carbon may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  The amount of solid carbon to be coexisted depends on the amount of the phosphor raw material to be processed at one time and other firing conditions, but from the viewpoint of the balance between the characteristics of the phosphor and the productivity, it is usually 0.1 wt. % Or more, preferably 1% by weight or more, more preferably 10% by weight or more, and further preferably 15% by weight or more.

Further, by using a graphite crucible as a firing container, it is possible to obtain the same effect as the coexistence of solid carbon. On the other hand, when a crucible made of a material other than carbon such as an alumina crucible is used, it is preferable that solid carbon such as graphite beads, granules and blocks coexist separately.
Note that firing is preferably performed under sealed conditions, such as by covering the crucible.

  Note that the firing in the coexistence of solid carbon is sufficient if the phosphor raw material and the solid carbon are present in the same firing container, and it is preferable to arrange them close to each other. Here, the phosphor raw material and solid carbon may be mixed and fired. In general, when carbon is mixed into the phosphor product, black carbon absorbs light emitted from the phosphor, so that the luminous efficiency of the phosphor is often lowered, so care must be taken.

  As a method of arranging the solid carbons in close proximity, for example, the solid carbons are put in a container different from the container containing the phosphor raw material, and these containers are placed in the same crucible (for example, in the upper part of the phosphor raw material container). (So that the solid carbon container is located), embed the container containing the solid carbon in the phosphor material, or conversely, arrange the solid carbon around the container filled with the phosphor material powder, etc. The method is mentioned. When a large crucible is used, it is preferable to take a method in which a container containing solid carbon is placed in the same container as the phosphor raw material and fired. In any case, it is preferable to devise so that solid carbon is not mixed in the phosphor material.

In the case of producing a phosphor having the chemical composition represented by the formula [1], as a method for obtaining a divalent ion of the M ^II element, in addition to the method of coexisting solid carbon described above, or a method of coexisting solid carbon. The following method can also be implemented. That is, it is preferable to remove the air present in the crucible as much as possible simultaneously with the powder of the phosphor raw material to lower the oxygen concentration. As a specific method, it is preferable to depressurize a crucible charged with a predetermined phosphor raw material in a vacuum furnace to remove air, and introduce an atmospheric gas used during firing to restore the pressure. Further, it is more preferable to repeat this operation. Alternatively, an oxygen getter such as Mo can be used as necessary. Further, if safety measures are taken, divalent ions of the M ^II element can also be obtained by firing in a nitrogen atmosphere containing 5% by volume or more of hydrogen.

The presence of solid carbon in this manner is preferable because the oxygen concentration in the firing atmosphere is reduced and the firing atmosphere is made a highly reducing atmosphere, whereby a phosphor with high characteristics can be obtained.
In addition, you may perform a baking process in multiple times.

・ Other oxide phosphor firing conditions
When producing oxide phosphors (other oxide phosphors) other than the phosphor having the chemical composition represented by the formula [1] (for example, the phosphor having the chemical composition represented by the formula [2] described later) In the case of manufacturing), the firing temperature (maximum temperature reached) varies depending on the intended phosphor, but is usually 700 ° C. or higher, preferably 800 ° C. or higher, more preferably 900 ° C. or higher. The temperature is usually 2000 ° C. or lower, preferably 1800 ° C. or lower, more preferably 1700 ° C. or lower.

The firing time in the production of other oxide phosphors is usually 1 hour or longer, preferably 5 hours or longer, although it varies depending on the temperature and pressure during firing. The firing time is preferably longer, but from the viewpoint of productivity, it is usually 24 hours or shorter, preferably 20 hours or shorter, more preferably 15 hours or shorter, and further preferably 12 hours or shorter.

  The pressure during firing in producing other oxide phosphors varies depending on the firing temperature and the like and is not particularly limited, but is usually 10 Pa or more, preferably 20 Pa or more, more preferably 0.05 MPa or more, and further preferably 0. The upper limit is usually 200 MPa or less, preferably 100 MPa or less, more preferably 1 MPa or less. Among these, industrially, atmospheric pressure (about 0.1 MPa) to about 1 MPa is preferable because it is simple in terms of cost and labor.

The firing atmosphere in the case of producing other oxide phosphors is not particularly limited, but usually a gas such as carbon monoxide, carbon dioxide, nitrogen, hydrogen, argon, etc., in any one single atmosphere, or It is performed in a mixed atmosphere of two or more. Moreover, you may coexist solid carbon as needed.
In addition, you may perform a baking process in multiple times.

・ Nitride phosphor firing conditions
When producing a nitride phosphor, the optimum temperature for the firing temperature (maximum temperature reached) varies depending on the intended phosphor, but is usually 1000 ° C. or higher, preferably 1200 ° C. or higher, more preferably 1400 ° C. or higher. The temperature is usually 2500 ° C. or lower, preferably 2300 ° C. or lower, more preferably 2100 ° C. or lower.

  The firing time in the production of the nitride phosphor is usually 1 hour or longer, preferably 2 hours or longer, although it varies depending on the temperature and pressure during firing. The firing time is preferably longer, but from the viewpoint of productivity, it is usually 24 hours or shorter, preferably 20 hours or shorter, more preferably 15 hours or shorter, and further preferably 12 hours or shorter.

  The pressure during firing in the case of producing a nitride phosphor is not particularly limited because it varies depending on the firing temperature and the like, but is usually 0.1 MPa or more, preferably 0.3 MPa or more, more preferably 0.5 MPa or more, and further preferably Is 0.8 MPa or more, and the upper limit is usually 300 MPa or less, preferably 200 MPa or less, more preferably 100 MPa or less. Among these, industrially, atmospheric pressure (about 0.1 MPa) to about 1 MPa is preferable because it is simple in terms of cost and labor.

The firing atmosphere for producing the nitride phosphor is not particularly limited, but is usually performed in an inert atmosphere such as nitrogen, argon, etc., either in a single atmosphere or in a mixed atmosphere of two or more. It is.
In addition, you may perform a baking process in multiple times.

(flux)
In the firing step, it is preferable to fire the phosphor material in the presence of the flux by allowing the reaction system to coexist with the flux from the viewpoint of growing good crystals. In particular, in the method for producing the phosphor of the present invention, it is preferable to use a water-soluble flux.
Here, the water-soluble flux refers to a compound having a solubility in water at 20 ° C. (g / 100 g of water) of 10 g or more. For example, NH ₄ Cl (solubility 37.2), NaCl (solubility 26.4), KCl (solubility 25.5), CsCl (solubility 65.1), CaCl ₂ (solubility 42.7), BaCl ₂ (solubility 26) .3), SrCl ₂ (solubility 35.8) and the like (the solubility is extracted from “Rika Chronology 2008” published by Maruzen Co., Ltd.).
Among these, those having a solubility in water of 20 (g / 100 g of water) or more are preferable, and those having a solubility of 30 (g / 100 g of water) or more are more preferable. Specifically, alkaline earth metal halides such as BaCl ₂ , SrCl ₂ and CaCl ₂ are preferable, and BaCl ₂ , SrC
l ₂ is more preferred, and SrCl ₂ is particularly preferred.
The water-soluble flux is a concept that includes a compound that is used as a raw material for a phosphor as long as it is a compound that exhibits the effects described below.
The water-soluble flux exhibits excellent effects such as promoting crystal growth. On the other hand, when the water-soluble flux is used, the baked cake tends to be hard, and as a result, when pulverizing in the pulverization step, it is necessary to apply a large force, and the surface of the phosphor particles may be damaged. is there. On the other hand, in the method for producing the phosphor of the present invention, it is possible to suppress damage to the phosphor particles by performing a softening step after firing in the presence of such a water-soluble flux. It is possible to obtain a phosphor that is good, nearly spherical, and excellent in light emission characteristics.

  Examples of the water-soluble flux include halides such as chloride, bromide, and iodide, borates, compounds having an alkali metal, compounds having an alkaline earth metal, and the like. Among these, a flux that works in a liquid phase during firing of chloride or the like is preferable.

More specific examples of the water-soluble flux suitable for the method for producing the phosphor of the present invention include NH ₄ Cl, LiCl, NaCl, KCl, CsCl, CaCl ₂ , BaCl ₂ , SrCl ₂ , YCl ₃ .6H _2. O (however, it may be an anhydride), NH ₄ Br, LiBr, NaB
r, KBr, CsBr, CaBr ₂ , BaBr ₂ , SrBr ₂ , YBr ₃ .6H ₂ O (however, they may be non-hydrated), NH ₄ I, LiI, NaI, KI, CsI, CaI ₂ , BaI ₂ , SrI ₂ , YI ₃ .6H ₂ O (but may be an anhydrate), NH ₄ F, LiF, NaF, YF ₃ , AlCl _{3 and the} like.
Among these, LiCl, CsCl, BaCl ₂ , SrCl _{2 and} CaCl ₂ are preferably used, and CsCl and SrCl ₂ are particularly preferably used.

Moreover, although it is also possible to use only said water-soluble flux as a flux, it is also possible to use a water-soluble flux and another flux together. Examples of such fluxes other than water-soluble flux are ZnCl ₂ , MgCl ₂ .6H ₂ O (however, it may be an anhydrate), chlorides such as RbCl, LiF, NaF, KF , Fluorides such as CsF, CaF ₂ , BaF ₂ , SrF ₂ , AlF ₃ , MgF ₂ , YF ₃ , K ₃ PO ₄ , K ₂ HPO ₄ , KH ₂ PO ₄ , Na ₃ PO ₄ , Na ₂ HPO ₄ , Phosphate such as NaH ₂ PO ₄ , Li ₃ PO ₄ , Li ₂ HPO ₄ , LiH ₂ PO ₄ , (NH ₄ ) ₃ PO ₄ , (NH ₄ ) ₂ HPO ₄ , (NH ₄ ) H ₂ PO ₄ Is mentioned.
In addition, as for water-soluble flux and other fluxes, all may use only 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

  Here, it is preferable to use an anhydride for the above-mentioned flux having deliquescence, and when the phosphor is produced by multi-stage firing, it is preferred to use the flux at the later stage firing.

  The amount of flux used (the total amount used when two or more fluxes are used in combination) varies depending on the phosphor material type, flux material, firing temperature, atmosphere, etc., but is usually 0.01% by weight. Or more, preferably 0.1% by weight or more, more preferably 1% by weight or more, particularly preferably 2% by weight or more, and usually 30% by weight or less, preferably 20% by weight or less, more preferably 15% by weight or less. It is a range. If the amount of flux used is too small, the effect of flux may not appear. If the amount of flux used is too large, the flux effect may be saturated, the particle size will be too large, the handleability will be poor, it will be incorporated into the host crystal and the emission color may be changed, or the brightness may be reduced. .

(Number of firings)
Note that the firing may be performed a plurality of times by dividing the firing step into primary firing and secondary firing. This is because firing multiple times tends to improve the characteristics of the phosphor, such as crystallinity and reliability, and is preferable. The specific number of firings is usually 1 to 7 times, and preferably 2 to 4 times in consideration of productivity and characteristics of the obtained phosphor.
When firing a plurality of times, the phosphor raw materials mixed in the mixing step may be fired and then pulverized again with a ball mill or the like and then fired again under the above-described firing conditions.

The firing conditions in the case where the first firing is primary firing, the second firing is secondary firing and the second firing is performed are described below.
The primary firing temperature (maximum temperature reached) is usually 850 ° C. or higher, preferably 1000 ° C. or higher, more preferably 1025 ° C. or higher, and usually 1350 ° C. or lower, preferably 1200 ° C. or lower, more preferably 1150 ° C. or lower. It is.

  The temperature increase rate of primary firing is usually 2 ° C./min or more, preferably 3 ° C./min or more, and usually 10 ° C./min or less, preferably 5 ° C./min or less. Below this range, the firing time may be longer. Moreover, when it exceeds this range, a baking apparatus, a container, etc. may be damaged.

  The pressure during primary firing is not particularly limited because it varies depending on the firing temperature and the like, but is usually 0.01 MPa or more, preferably 0.1 MPa or more, and usually 200 MPa or less, preferably 100 MPa or less. Among these, industrially, it is usually about atmospheric pressure to about 0.3 MPa, and atmospheric pressure is preferable in terms of cost and labor.

  The atmosphere during the primary firing is not particularly limited, and may be performed in an atmosphere having a low oxygen concentration as described above. It does not necessarily have to be in an atmosphere having a low oxygen concentration or in a reducing atmosphere. For example, it may be performed in an inert atmosphere such as nitrogen or argon. However, the emission intensity may decrease when performed in an oxygen atmosphere.

  The primary firing time is usually in the range of 1 hour or longer, preferably 2 hours or longer, more preferably 4 hours or longer, and usually 24 hours or shorter, preferably 15 hours or shorter, more preferably 13 hours or shorter.

  The conditions such as the temperature and time of the secondary firing are basically the same as the conditions described in the above-described firing conditions and description of the flux.

  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.

[1-5. High temperature firing process]
In addition, it is preferable to provide a step of firing at a temperature higher than the firing step (hereinafter sometimes referred to as “high temperature firing step”) before performing the firing step. When dividing the firing step into primary firing and secondary firing, a step of firing at a temperature higher than the secondary firing between the primary firing and the secondary firing (a high temperature firing step, which will be described later). In the embodiment, “1.5th order firing” can be added. As a result, a single particle phosphor having a flat and clean surface is obtained, and the luminance and reliability are improved.
The firing temperature (maximum reached temperature) in the high-temperature firing step is higher than the temperature described in the above-mentioned (baking conditions) (when the firing step is divided into primary firing and secondary firing, it refers to the temperature of secondary firing). It is desirable that the temperature is high, preferably 25 ° C. or higher, and usually 100 ° C. or lower, preferably 50 ° C. or lower, than the temperature for secondary firing. If the firing temperature is lower than the temperature of the firing step (secondary firing when the firing step is divided into primary firing and secondary firing), it may be difficult to obtain the effect of flattening the surface of the phosphor. If the firing temperature is too high, the fired product may be discolored. In the high temperature firing step, conditions other than the firing temperature are the same as those described in the above description of the firing conditions, and a small amount of flux may be added in the high temperature firing step.

[1-5. Softening process]
The method for producing a phosphor of the present invention includes a softening step of softening a fired product (baked cake) obtained by the firing step.
The phosphor is generally manufactured by firing the phosphor raw material under desired firing conditions as described in the above-described firing step. In many cases, the phosphor is fired under high temperature conditions. The object is hard and sintered. In particular, as described in the above (Flux) section, when firing in the presence of a water-soluble flux, the fired product tends to become hard. This step is a step of softening the baked cake thus hardly sintered.

  In this step, usually, the baked product lump (baked cake) can be easily crushed with a mortar and pestle. Preferably, the mortar and pestle can pass through a mesh having an opening size of about 500 μm. It is preferable to soften the fired product to such an extent that it can be easily crushed.

  The specific method of the softening step is not particularly limited as long as it is a method that can soften the fired product as described above. For example, water vapor molecules have a higher kinetic energy than water molecules, and can move into the gaps between the phosphor particles by freely moving around and penetrate into the fired product to soften the fired product. Therefore, the fired product may be placed in the presence of steam, preferably in the presence of water vapor.

When softening is performed by placing the fired product in the presence of water vapor, the temperature is usually 50 ° C. or higher, preferably 80 ° C. or higher, more preferably 100 ° C. or higher, and usually 300 ° C. or lower, preferably 200 ° C. or lower. More preferably, it is 150 degrees C or less. If the temperature is too low, the effect of softening tends to be difficult to obtain, and if it is too high, the surface of the phosphor particles may be roughened.
In addition, what is necessary is just to set temperature suitably to such an extent that a softening effect is acquired when performing a softening process with steam other than water vapor | steam.

  In addition, when softening is performed by placing the fired product in the presence of steam, the humidity (relative humidity) is usually 50% or more, preferably 80% or more, and particularly preferably 100%. If the humidity is too low, the effect of softening tends to be difficult to obtain. Note that the liquid phase may coexist in the gas phase having a humidity of 100% as long as the softening effect is obtained.

Furthermore, when softening is performed by placing the fired product in the presence of steam, the pressure is usually normal pressure or higher, preferably 0.12 MPa or higher, more preferably 0.3 MPa or higher, and usually 10 MPa or lower, preferably 1 MPa. Hereinafter, it is more preferably 0.5 MPa or less. Low pressure
If it is too high, the effect of softening tends to be difficult to obtain, and if it is too high, the processing apparatus becomes large, and there may be a problem of work safety.

  When softening is performed by placing a fired product in the presence of steam, the time for holding the fired body in the presence of steam is not uniform depending on the temperature, humidity and pressure, but is usually high. The higher the humidity and the higher the pressure, the shorter the holding time. Specific ranges of time are usually 0.5 hours or more, preferably 1 hour or more, more preferably 1.5 hours or more, and usually 200 hours or less, preferably 100 hours or less, more preferably 12 hours. Hereinafter, it is more preferably 5 hours or less.

When the softening step is performed while satisfying the above conditions, a typical softening method is a method of placing in an autoclave under high humidity and high pressure. Here, in addition to the autoclave or instead of using the autoclave, an apparatus that can be subjected to high temperature and high humidity conditions such as a pressure cooker may be used. As the pressure cooker, for example, TPC-412M (manufactured by ESPEC Co., Ltd.) can be used. According to this, the temperature is 105 ° C. to 162.2 ° C. and the humidity is 75 to 100% (however, the temperature condition The pressure can be controlled to 0.020 MPa to 0.392 MPa (0.2 kg / cm ^{2 to} 4.0 kg / cm ² ).

If the softened step is performed while holding the fired product in the autoclave, the softening can be performed in an environment of high temperature, high pressure and high humidity, so that the softening can be performed particularly in a short time. Specifically, the fired product may be placed in an environment where the pressure is normal pressure (0.1 MPa) or more and steam is present for 0.5 hour or more.
More preferable conditions are described below. The pressure is preferably 0.2 MPa or more, more preferably 0.3 MPa or more, and usually 10 MPa or less, preferably 1 MPa or less, more preferably 0.5 MPa or less. The steam is preferably saturated steam (steam when the gas phase and the liquid phase coexist in equilibrium under a certain pressure). The fired product is preferably left for 1 hour or longer, more preferably 1.5 hours or longer, and usually 12 hours or shorter, preferably 5 hours or shorter, more preferably 3 hours or shorter.
Note that the fired product may be put in an autoclave after being put in a container made of alumina or magnet. At this time, the fired product may be pulverized in advance, but if pulverized, the phosphor particles may be damaged. Therefore, to maximize the effect of the softening process, the baked product is crushed. It is preferable to put the container as it is.

Further, in the softening step, the following method may be used in place of the method of placing in an autoclave under high humidity and high pressure.
(I) While exposing the fired product to the atmosphere, it may be kept at room temperature for a relatively long time, for example, usually 20 hours or more, preferably 50 hours or more, more preferably 100 hours or more. The upper limit of the time for which the fired product is kept at room temperature is not particularly limited, but it is preferable to set the time so that the fired product does not deteriorate.
Here, the fired product is preferably not stored in a bag or a container such as a plastic bag, for example, so that the contact area between the fired product and the atmosphere is increased. Furthermore, you may adjust the humidity around a baked material as needed, for example using a humidifier.
(Ii) The fired product may be subjected to humidification conditions, preferably high-temperature humidification conditions, under normal pressure. Various conditions such as humidity and time in this case are as described above.

  In this way, the softening step makes it soft even if it is a hard fired product, so that in the pulverization step described later, even if the phosphor has weak mechanical strength, the phosphor particles are not damaged more than necessary. Can be crushed. For this reason, according to the method for producing a phosphor of the present invention, phosphor particles closer to a true sphere than that produced by the conventional method are obtained, and the emission peak intensity is improved. In addition, the working efficiency of the grinding process is greatly improved.

  In the above method, the water vapor is exemplified, but a vapor of a solvent that can dissolve the flux can be used instead of or in addition to the water vapor. Examples of the solvent that can dissolve the flux include organic solvents such as alcohol. It is also possible to use a mixture of two or more solvent vapors in an arbitrary ratio.

[1-6. Other processes]
In the method for producing a phosphor of the present invention, steps other than those described above may be performed as long as the effects of the present invention are not significantly impaired.
For example, after the heat treatment in the above-described firing step, post-treatment steps such as a pulverization step, a washing step, a drying step, and a classification step may be performed as necessary.

The pulverization step is performed on the fired product when, for example, the obtained phosphor does not have a desired particle size. The pulverization method is not particularly limited. For example, the dry pulverization method and the wet pulverization method described in the description of the phosphor raw material mixing step can be used, but the destruction of the generated phosphor crystal is suppressed, and the intended treatment such as secondary particle crushing is performed. In order to proceed, for example, balls such as alumina, silicon nitride, ZrO ₂ , glass and the like, or balls such as iron cored urethane are placed and ball milling is performed for about 10 minutes to 24 hours. Is preferred. In this case, you may use 0.05 weight%-2weight% of dispersing agents, such as alkali phosphates, such as organic acid and hexametaphosphoric acid.

In particular, when the fired product is not sufficiently softened and hard even after the softening step, it is preferable to grind the fired product after the softening step using a grinder having a mortar structure. This is because work efficiency can be dramatically improved. Here, a grinder mill etc. are mentioned as a specific example of the grinder which has mortar structure.
The pulverizer having this mortar structure is one in which pulverization is performed when a fired product passes between pulverization devices installed on the upper and lower sides, for example, disks. As an effect when using a pulverizer having a mortar structure, the fired product that is smaller than the gap between the disks is not further pulverized, so by adjusting the distance between the disks, It is not necessary to damage the fired product by pulverization more than necessary. Further, since the fired product is automatically discharged from the gap between the disks, continuous grinding can be performed only by adjusting the charging timing. In addition, the time from when the fired product is actually charged until it is discharged is about several seconds, which is a pulverizer with very high pulverization efficiency.

As conditions for pulverizing the fired product using a grinder mill, the rotation speed is usually 600 rpm or more, preferably 1000 rpm or more, more preferably 1500 rpm or more, and usually 6000 rpm or less, preferably 3000 rpm or less, more preferably 2000 rpm. The following. If the rotational speed is too low, the pulverization efficiency tends to decrease, and if the rotational speed is too high, fine particles tend to be generated. The interval between the disks is usually 10 μm or more, preferably 20 μm or more, more preferably 40 μm or more, and usually 2000 μm or less, preferably 1500 μm or less, more preferably 1000 μm or less. If the distance between the disks is too wide, the grinding efficiency tends to decrease, and if the distance between the disks is too narrow, fine particles tend to be generated.
Furthermore, it is more preferable to use a normal pulverizing means (such as a ball mill) after the pulverization because work efficiency is improved.

  The washing treatment can be performed, for example, with water such as deionized water, an organic solvent such as ethanol, or an alkaline aqueous solution such as ammonia water. In addition, for the purpose of removing the impurity phase adhering to the phosphor surface such as the flux used and improving the light emission characteristics, for example, an inorganic acid such as hydrochloric acid, nitric acid, sulfuric acid; or an organic acid such as acetic acid. An aqueous solution of can also be used. In this case, it is preferable to further wash with water after washing in an acidic aqueous solution.

As the degree of washing, it is preferable that the pH of the supernatant obtained by dispersing the washed phosphor in water 10 times by weight and allowing it to stand for 1 hour is neutral (about pH 7 to 9). This is because if it is biased toward basicity or acidity, the liquid medium or the like may be adversely affected when mixed with the liquid medium or the like described later.
The degree of washing can also be expressed by the electrical conductivity of the supernatant obtained by dispersing the washed phosphor in 10 times the weight ratio of water and allowing it to stand for 1 hour. The electrical conductivity is preferably as low as possible from the viewpoint of light emission characteristics. However, in consideration of productivity, the washing treatment is usually repeated until it is 1000 mS / m or less, preferably 500 mS / m or less, more preferably 100 mS / m or less. It is preferable.

  As a method for measuring electrical conductivity, phosphor particles having a specific gravity heavier than water are obtained by stirring and dispersing in water 10 times the weight of the phosphor for a predetermined time, for example, 10 minutes, and then allowing to stand for 1 hour. The electrical conductivity of the supernatant liquid at this time may be measured using an electrical conductivity meter “EC METER CM-30G” manufactured by Toa Decay Co., Ltd. Although there is no restriction | limiting in particular as water used for a washing process and a measurement of electrical conductivity, Demineralized water or distilled water is preferable. Among them, those having particularly low electric conductivity are preferable, and those having a conductivity of usually 0.0064 mS / m or more, and usually 1 mS / m or less, preferably 0.5 mS / m or less are used. The electrical conductivity is usually measured at room temperature (about 25 ° C.).

  The classification step can be performed, for example, by performing a water sieve or a water tank treatment, or by using various classifiers such as various air classifiers or vibrating sieves. In particular, when dry classification using a nylon mesh is used, a phosphor with good dispersibility having a weight median diameter of about 20 μm can be obtained.

  Moreover, it is preferable to perform a drying process after a washing | cleaning process. Although there is no restriction | limiting in particular in the drying method in a drying process, It is preferable to select a drying processing method suitably according to the property of fluorescent substance. For example, when the phosphor of the present invention is exposed to a high-temperature and high-humidity atmosphere (for example, hot water) for a long time, a part of the surface of the phosphor matrix is dissolved, and the dissolved part is carbon dioxide in the air. May react to carbonate. Therefore, when performing the drying treatment, for example, low temperature drying such as vacuum drying, reduced pressure drying, freeze drying, and short time drying such as spray drying are preferable, and in an atmosphere not containing carbon dioxide such as nitrogen or argon gas. A method of drying or air-drying by replacing moisture with a low boiling point solvent is preferred.

  Moreover, when manufacturing a light-emitting device by the method described later using the phosphor obtained by the above procedure, the phosphor of the light-emitting device described later is used to further improve weather resistance such as moisture resistance. In order to improve the dispersibility with respect to the resin in the containing portion, a surface treatment such as coating the surface of the phosphor with a different substance may be performed as necessary.

Examples of substances that can be present on the surface of the phosphor (hereinafter referred to as “surface treatment substances” as appropriate) include organic compounds, inorganic compounds, glass materials, and the like.
Examples of the organic compound include acrylic resins, polycarbonates, polyamides, hot-melt polymers such as polyethylene, latex, polyorganosiloxane, and the like.
Examples of inorganic compounds include magnesium oxide, aluminum oxide, silicon oxide, titanium oxide, zirconium oxide, tin oxide, germanium oxide, tantalum oxide, niobium oxide, vanadium oxide, boron oxide, antimony oxide, zinc oxide, yttrium oxide, oxide Examples thereof include metal oxides such as lanthanum and bismuth oxide, metal nitrides such as silicon nitride and aluminum nitride, orthophosphates such as calcium phosphate, barium phosphate, and strontium phosphate, and polyphosphates. And at least one selected from the group consisting of lithium phosphate, sodium phosphate, and potassium phosphate, and at least one selected from the group consisting of barium nitrate, calcium nitrate, strontium nitrate, barium hydrochloride, calcium hydrochloride, and strontium hydrochloride. Can also be used in combination. Among them, it is preferable to use a combination of sodium phosphate and calcium nitrate. Further, when barium, calcium, or strontium is present on the phosphor surface, the surface treatment can be carried out using only a phosphate such as sodium phosphate.
Examples of the glass material include borosilicate, phosphosilicate, and alkali silicate.
Any one of these surface treatment substances may be used alone, or two or more kinds thereof may be used in any combination and ratio.

The phosphor subjected to the surface treatment has these surface treatment substances. Examples of the presence of the surface treatment substance include the following.
(I) A mode in which the surface treatment substance constitutes a continuous film and covers the surface of the phosphor.
(Ii) A mode in which the surface treatment substance is coated with the surface of the phosphor by forming a large number of fine particles and adhering to the surface of the phosphor.

  The adhesion amount or coating amount of the surface treatment substance on the surface of the phosphor is usually 0.1% by weight or more, preferably 1% by weight or more, more preferably 5% by weight or more, based on the weight of the phosphor. It is usually 50% by weight or less, preferably 30% by weight or less, and more preferably 15% by weight or less. If the amount of the surface treatment substance relative to the phosphor is too large, the light emission characteristics of the phosphor may be impaired. If the amount is too small, the surface coating will be incomplete, and the moisture resistance and dispersibility will not be improved. There is.

  Further, the film thickness (layer thickness) of the surface treatment substance formed by the surface treatment is usually 10 nm or more, preferably 50 nm or more, and usually 2000 nm or less, preferably 1000 nm or less. If the film thickness is too thick, the light emission characteristics of the phosphor may be impaired. If the film thickness is too thin, the surface coating may be incomplete and the moisture resistance and dispersibility may not be improved.

The surface treatment method is not particularly limited, and examples thereof include a coating treatment method using a metal oxide (silicon oxide) as described below.
The phosphor is mixed in an alcohol such as ethanol and stirred, and further an alkaline aqueous solution such as ammonia water is mixed and stirred. Next, a hydrolyzable alkyl silicate such as tetraethylorthosilicate is mixed and stirred. The obtained solution is allowed to stand for 3 to 60 minutes, and then the supernatant containing silicon oxide particles that have not adhered to the phosphor surface is removed with a dropper or the like. Subsequently, after mixing alcohol, stirring, standing, and removing the supernatant several times, a surface-treated phosphor is obtained through a reduced-pressure drying step at 120 ° C. to 150 ° C. for 10 minutes to 5 hours, for example, 2 hours.

Other methods for surface treatment of the phosphor include, for example, a method in which spherical silicon oxide fine powder is adhered to the phosphor (JP-A-2-209998, JP-A-2-233794), and a phosphor-based silicon compound. A method of attaching a film (Japanese Patent Laid-Open No. 3-231987), a method of coating the surface of phosphor fine particles with polymer fine particles (Japanese Patent Laid-Open No. 6-314593), a phosphor with an organic material, an inorganic material, a glass material, etc. A coating method (Japanese Patent Laid-Open No. 2002-223008), a method of coating a phosphor surface by a chemical vapor reaction method (Japanese Patent Laid-Open No. 2005-82788), and a method of attaching metal compound particles (Japanese Patent Laid-Open No. 2006-2006) No. 28458) can be used.
In addition to the above-described treatment, a generally known technique is used for known phosphors, for example, phosphors used in cathode ray tubes, plasma display panels, fluorescent lamps, fluorescent display tubes, X-ray intensifying screens, and the like. And can be selected as appropriate according to the purpose and application.

[1-7. Advantages of this manufacturing method]
According to the method for producing a phosphor of the present invention, the impact given to the phosphor particles during pulverization or the like can be reduced. Therefore, when trying to reduce the particle size of a very hard phosphor, the conventional production method may damage the phosphor particles because a large force is applied to the phosphor. The method for producing the phosphor of the present invention According to the present invention, since the sintered body of the phosphor particles (that is, the fired product of the phosphor raw material) can be softened by the softening process, the powder can be pulverized with a smaller force than before. It can suppress that a body particle is damaged. Therefore, the phosphor particles produced by the method for producing a phosphor of the present invention have few scratches, and the shape thereof is close to a true sphere. The specific form is usually the same as that of the phosphor of the present invention described later. For this reason, the obtained phosphor is excellent in handleability and light emission characteristics.

  Moreover, the manufacturing method of the fluorescent substance of this invention is applicable also when manufacturing the fluorescent substance with a large particle size to some extent. The specific particle diameter varies depending on the composition and the like, but the phosphor production method of the present invention can also be applied to the production of a phosphor having a weight median diameter of usually 5 μm or more, preferably 10 μm or more. . For this reason, the phosphor obtained by the method for producing a phosphor according to the present invention can be suitably applied even when used in combination with a semiconductor light emitting device, and its application can be expanded.

The phosphor to which the method for producing a phosphor of the present invention can be applied is not particularly limited, and various phosphors based on, for example, oxides, oxynitrides, nitrides, sulfides and carbides can be produced. Moreover, there is no restriction | limiting in particular in the structural element and crystal system of the fluorescent substance which can apply the manufacturing method of the fluorescent substance of this invention. Examples of applicable phosphor crystal structures include (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu and other orthosilicate crystal structures such as Ca ₃ (Sc, Mg, Na, Li) ₂ Si ₃ O. ₁₂ : Garnet-based crystal structure such as Ce, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Apatite-based crystal structure such as Eu, M ₃ Si ₆ O ₁₂ N ₂ : Eu (provided that M Represents an alkaline earth metal element)) and the like. Among these, an orthosilicate crystal structure or a garnet crystal structure is preferable. This is because the fired phosphors having these crystal structures tend to be hard. In particular, in the case of a phosphor containing Si, a phosphor material having a low melting point such as SiO ₂ is often used, and the fired product tends to be hard. In such a case, it is effective to perform a softening step. is there.
According to the production method of the present invention, even when the production scale is small, the ratio of particles having a circularity of less than 85% is reduced and the relative luminance is improved. Further, in industrial production with a large scale, in addition to the effect that the proportion of particles having a circularity of less than 85% is reduced and the relative luminance is improved, the 4-minute deviation in particle size is 0.4 or less. In addition, the productivity is greatly improved.
The production method having the softening step of the present invention is particularly suitable for industrial production with a large scale. For example, the amount of the baked cake to be subjected to the softening step is usually 200 g or more, preferably 300 g or more. More preferably, a softening step is provided when the weight is 400 g or more. Moreover, as an upper limit of the quantity of the baking cake provided to a softening process, if the effect of a softening process is acquired, there will be no restriction | limiting, Usually, it is 10000 g or less, and it is preferable to set it as 1000 g or less.

[2. Phosphor]
Since the phosphor produced by the method for producing a phosphor of the present invention is suppressed from being damaged, it has excellent light emitting characteristics such as luminance and is easy to handle. In addition, the phosphor production method of the present invention is particularly difficult to suppress damage caused during pulverization or the like in the conventional production method because of the high hardness of the fired body obtained by the firing step. It is particularly suitable for use in a production method.
Hereinafter, a phosphor suitable for the method for producing a phosphor of the present invention and having an effect such as an improvement in light emission characteristics only by the method for producing a phosphor of the present invention (hereinafter referred to as “the phosphor of the present invention” as appropriate). Will be explained.

[2-1. Phosphor composition]
The phosphor of the present invention is a phosphor having an alkaline earth metal element as part of the host crystal. Examples of the alkaline earth metal element include Ca, Sr, Ba, Zn, and Mg. Among them, Ca, Sr, and Ba are preferable, and Sr and Ba are more preferable. Since Zn and Mg have an effect of promoting particle growth, it may be difficult to control the particle size. When Ca is excessively contained, the luminance may be lowered. In addition, the fluorescent substance of this invention may contain only 1 type of alkaline-earth metal elements, and may contain 2 or more types by arbitrary combinations and ratios.
The phosphor of the present invention preferably contains Si in addition to the above alkaline earth metal element. Part or all of this Si may be replaced with Ge.
The phosphor of the present invention preferably contains Eu as an activator element. In addition to Eu, Tb and / or Ce may be further contained as a coactivator element. When the coactivator element is contained, the durability of the phosphor tends to be improved.

Specific examples of the composition of the phosphor of the present invention include (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu and Ca ₃ (Sc, Mg, Na, Li) ₂ Si ₃ O ₁₂ : Ce. And those represented by the composition formula selected from the group consisting of: This is because the phosphors represented by these composition formulas are very hard and are suitable for the method for producing the phosphor of the present invention.

The phosphor represented by the composition formula of (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu preferably has a chemical composition represented by the following formula [1].
(M ^I _(1-xy) M ^II _x M ^III _y ) _α SiO _β [1]
(In the formula [1], M ^I represents one or more elements selected from the group consisting of Ba, Ca, Sr, Zn, and Mg, and M ^II can take a divalent or trivalent valence. M ^III represents one or more metal elements, M ^III represents one or more elements selected from the group consisting of Tb, Pr, Ce, Lu, La, and Gd, and x, y, α, and β are respectively 0.01 <x <0.3, 0 ≦ y ≦ 0.025, 1.5 ≦ α ≦ 2.5, and 3.5 ≦ β ≦ 4.5.

In the formula [1], M ^I represents one or more elements selected from the group consisting of Ba, Ca, Sr, Zn, and Mg. As M ^I , any one of these elements may be contained alone, or two or more may be contained in any combination and ratio.

Among them, M ^I preferably contains at least Ba. In this case, the molar ratio of Ba to the entire M ^I is usually 0.4 or more, preferably 0.45 or more, more preferably 0.5 or more, and usually less than 1, particularly 0.97 or less, and more preferably 0.8. A range of 9 or less, particularly 0.8 or less is preferred. If the molar ratio of Ba is too high, the emission peak wavelength tends to shift to the short wavelength side. On the other hand, if the molar ratio of Ba is too low, the light emission efficiency tends to decrease.

In particular, M ^I preferably contains at least Ba and Sr. Here, when the molar ratios of Ba and Sr to the entire M ^I are [Ba] and [Sr], respectively, the ratio of [Ba] to the sum of [Ba] and [Sr], that is, [Ba] / ([Ba ] + [Sr]) is usually larger than 0.4, preferably 0.5 or more, more preferably 0.55 or more, and usually 1 or less, especially 0.9 or less, Is preferably in the range of 0.8 or less. If the value of [Ba] / ([Ba] + [Sr]) is too small (that is, the ratio of Ba is too small), the emission peak wavelength of the phosphor shifts to the longer wavelength side, and the half-value width increases. Tend. On the other hand, if the value of [Ba] / ([Ba] + [Sr]) is too large (that is, the ratio of Ba is too large), the emission peak wavelength of the phosphor tends to shift to the short wavelength side.

  On the other hand, when it is desired to obtain a phosphor having a narrow emission peak half-value width, the relative ratio between [Ba] and [Sr], that is, the value represented by [Ba] / [Sr] is usually from 1. In particular, it is preferably 1.2 or more, more preferably 1.5 or more, particularly 1.8 or more, and usually 15 or less, especially 10 or less, more preferably 5 or less, particularly 3.5 or less. It is preferable. If the value of [Ba] / [Sr] is too small (that is, the ratio of Ba is too small), the emission peak wavelength of the phosphor tends to shift to the longer wavelength side and the half-value width tends to increase. On the other hand, if the value of [Ba] / [Sr] is too large (that is, the ratio of Ba is too large), the emission peak wavelength of the phosphor tends to shift to the short wavelength side.

In the formula [1], when M ^I contains at least Ca, substitution with Ca
As for the amount, when the total of M ^I and M ^II is 2, the value of the molar ratio of Ca to the total of M ^I and M ^II is usually 0.005 or less, particularly 0.0005 or less, more preferably 0.0002 or less. It is preferable that it is the range of these. If the ratio of the Ca content is too high, light emission tends to be yellowish and the light emission efficiency tends to decrease. Therefore, the smaller the Ca content, the better, but usually 0.000001 or more, especially 0.000005 or more, A range of 0.00001 or more is preferable. Since Ca may be included in the manufacturing process such as being contained in other raw materials, the amount of Ca to be contained may be adjusted in consideration of them.

  Further, Si may be partially substituted by other elements such as Ge. However, from the standpoint of green emission intensity and the like, it is preferable that the ratio of Si substituted by other elements is as low as possible. Specifically, other elements such as Ge may be contained in an amount of 20 mol% or less of Si, and it is more preferable that all are made of Si.

In the formula [1], M ^II is listed as an activator element and represents one or more metal elements that can have a divalent and trivalent valence. Specific examples include transition metal elements such as Cr and Mn; rare earth elements such as Eu, Sm, Tm, and Yb. As M ^II , any one of these elements may be contained alone, or two or more may be contained in any combination and ratio. Among them, as the M ^II Sm, Eu, Yb are preferred, Eu is particularly preferable. Among them, the proportion of Eu to the total M ^II is preferably at least 50 mol%, and more preferably 80 mol% or more. Further, the molar ratio of the divalent element to the entire M ^II (the sum of the divalent element and the trivalent element) is usually 0.5 or more, preferably 0.7 or more, more preferably 0.8 or more, Usually, it is less than 1, and the closer to 1, the better. If the molar ratio of the divalent element to the entire M ^II is too low, the light emission efficiency tends to decrease. This is because a divalent element and a trivalent element are taken into the crystal lattice, but it is considered that the trivalent element absorbs emission energy in the crystal.

In the formula [1], M ^III represents one or more elements selected from the group consisting of Tb, Pr, Ce, Lu, La, and Gd. The M ^III, any one of these elements may be contained in alone, or two or more may be of them together in any combination and in any ratio.
These Tb, Pr, Ce, Lu, La, and Gd have the property of low ionization energy. For example, Tb, Pr, and Ce tend to change from divalent to trivalent, and easily change from trivalent to tetravalent. Lu, La, and Gd are likely to change from divalent to trivalent. Thus, it is preferable to coexist an element having a small ionization energy, since it is possible to suppress a change in the valence of Eu and improve durability.

M ^III contributes to light emission together with M ^II , and is presumed to function as a coactivator element. That is, for example, when Tb is contained as M ^III , the same change in emission spectrum as when M ^II (an activator element, eg, Eu) is excessively contained is observed. That is, the emission peak wavelength shifts to the longer wavelength side, but no change is seen in the half-value width of the emission spectrum, and a green emission spectrum with high color purity can be maintained. Therefore, it is speculated that M ^III including Tb contributes to light emission together with M ^II and functions as a coactivator element.

Among these, M ^III is preferably one or more elements selected from the group consisting of Tb, Pr and Ce, more preferably contains at least Tb, and particularly preferably consists only of Tb. When containing Tb as M ^III, the case of manufacturing a light-emitting device by combining (first luminous body to be described later) and a light source such as a phosphor and a semiconductor light emitting device, the durability than with only M ^II as activating element As a result, the spectral shape change when the lamp is lit for a long time is small and the color shift is small. Further, when Tb is added in a specific range, the temperature characteristics can also be improved. It is presumed that the same effect as Tb can be obtained with other elements other than Tb.
Incidentally, Ag, a monovalent metal element such as Au may be used in combination as M ^III.

In the above formula [1], x is a number representing the number of moles of M ^II, specifically, greater than 0.01, preferably 0.02 or more, more preferably 0.03 or more, particularly preferably Represents a number of 0.04 or more, usually less than 0.3, preferably 0.2 or less, more preferably 0.16 or less. If the value of x is too small, the emission intensity tends to decrease. On the other hand, if the value of x is too large, the emission intensity tends to decrease.

In the above formula [1], y is a number representing the number of moles of M ^III , specifically, usually 0 or more, preferably 0.0001 or more, more preferably 0.001 or more, and still more preferably 0.00. It represents a number of 002 or more, usually 0.025 or less, preferably 0.02 or less, more preferably 0.015 or less. If the value of y is too small, the durability improving effect tends to be difficult to obtain. On the other hand, if the value of y is too large, the temperature characteristics tend to deteriorate. In particular, when it is desired to obtain a phosphor having excellent durability and excellent temperature characteristics, it is preferable to adjust the value of y to a range of 0.002 to 0.01.

  In the formula [1], α is preferably close to 2, but is usually 1.5 or more, preferably 1.7 or more, more preferably 1.8 or more, and usually 2.5 or less, preferably 2 .3 or less, more preferably 2.2 or less. If the value of α is too small or too large, heterogeneous crystals appear, and the light emission characteristics tend to deteriorate.

  In the formula [1], β is usually 3.5 or more, preferably 3.8 or more, more preferably 3.9 or more, and usually 4.5 or less, preferably 4.4 or less, more preferably 4 Represents a number in the range of 1 or less. If the value of β is too small or too large, heterogeneous crystals appear and the light emission characteristics tend to deteriorate.

Further, the phosphor having the chemical composition represented by the formula [1] is not limited to the elements described in the formula [1], that is, M ^I , M ^II , M ^III , Si (silicon) and O (oxygen). Furthermore, an element selected from the group consisting of a monovalent element, a divalent element, a trivalent element, a −1 valent element, and a −3 valent element (hereinafter referred to as “trace element” as appropriate) is contained. You may do it.

  Among these, as trace elements, alkali metal elements, alkaline earth metal elements, zinc (Zn), yttrium (Y), aluminum (Al), scandium (Sc), phosphorus (P), boron (B), nitrogen (N ), At least one element selected from the group consisting of rare earth elements and halogen elements.

  The total content of the trace elements is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less. When the phosphor of the present invention contains plural kinds of trace elements, the total amount thereof satisfies the above range.

  Specific examples of preferred compositions of the phosphor having the chemical composition represented by the formula [1] are listed in Table 1 below, but the composition of the phosphor of the present invention is not limited to the following examples.

  The phosphor of the present invention may contain Al in addition to the above elements. The Al content is usually 1 ppm or more, preferably 5 ppm or more, more preferably 10 ppm or more, and usually 500 ppm or less, preferably 200 ppm or less, more preferably 100 ppm or less.

  The phosphor of the present invention may contain B (boron) in addition to the above elements. The content of B is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less.

  The phosphor of the present invention may contain Fe in addition to the above elements. The Fe content is usually 1 ppm or more, preferably 3 ppm or more, more preferably 5 ppm or more, and usually 100 ppm or less, preferably 50 ppm or less, more preferably 30 ppm or less.

  The phosphor of the present invention may contain N in addition to the above elements. The content of N is usually 10 mol% or less, preferably 5 mol% or less, more preferably 3 mol% or less with respect to the amount of oxygen contained in the phosphor.

The phosphor of the present invention preferably contains an element derived from a water-soluble flux in an amount of usually 1 ppm or more, preferably 5 ppm or more, more preferably 10 ppm or more.
Here, examples of the element derived from the water-soluble flux include Cl, Br, I, B, Li, Na, K, Rb, Cs, Mg, Zn, and Bi. Especially, since it is an element which comprises the flux with high solubility to water, it is preferable to contain Cl and Cs. In addition, the fluorescent substance of this invention may contain only 1 type of elements derived from a water-soluble flux, and may contain 2 or more types.
In the phosphor manufactured using the water-soluble flux, the fired body obtained by the firing process is very hard, and when manufactured by the conventional manufacturing method, the phosphor particles are easily damaged by pulverization. However, when the phosphor is manufactured by the method for manufacturing a phosphor of the present invention, the above-described damage can be suppressed, and therefore, it is preferable to manufacture the phosphor using the method for manufacturing a phosphor of the present invention.
The upper limit of the content of the element derived from the water-soluble flux is arbitrary as long as the effects of the present invention are not significantly impaired. More preferably, it is 0.1% by weight or less, and particularly preferably 0.05% by weight or less.
The element derived from the water-soluble flux does not necessarily have to be derived from the water-soluble flux, and may be derived from, for example, a phosphor material.

[2-2. Crystal structure]
The phosphor of the present invention is a phosphor having an orthosilicate or garnet crystal structure. Among them, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu and Ca ₃ (Sc, Mg, N
a, Li) ₂ Si ₃ O ₁₂ : Ce is preferably represented by a composition formula selected from the group consisting of Ce.
Examples of the orthosilicate crystal structure include a phosphor having a chemical composition represented by the above formula [1]. On the other hand, when an example of a garnet crystal structure is given, a phosphor represented by the following formula [2] can be mentioned.
M ¹ _a M ² _b X _c M ³ _d M ⁴ ₃ O _e [2]
(In the formula [2], M ¹ represents Mg or / and Zn, M ² represents a divalent metal element excluding Mg and Zn, X represents a metal element of a luminescent center ion mainly composed of Ce, M ³ represents a trivalent metal element excluding X, M ⁴ represents a tetravalent metal element, and a, b, c, d, and e each represent a number that satisfies the following formula.
0.001 ≦ a ≦ 0.5
2.5 ≦ b ≦ 3.3
0.005 ≦ c ≦ 0.5
1.5 ≦ d ≦ 2.2
e = {(a + b) × 2 + (c + d) × 3 + 12} / 2)

  Further, the phosphor of the present invention is preferably as the crystallite diameter is larger, and is usually 20 nm or more, and preferably 100 nm or more. Here, the crystallite diameter can be obtained by measuring a half width in powder X-ray diffraction. It is believed that non-radiative deactivation occurs at the interface between crystallites, and conversion of luminescence energy into thermal energy occurs. When the crystallite is large, the crystallite interface is reduced, so that the conversion to heat energy is small and the luminance is increased.

[2-3. Form]
The phosphor of the present invention has a feature that the particle diameter is smaller than that of the conventional phosphor and there are few cracked particles and it is almost spherical. Among them, when the phosphor production method of the present invention promotes particle growth using the aforementioned water-soluble flux and performs a softening step, a phosphor having a beautiful shape is obtained. I think. When each phosphor particle is nearly spherical, the external quantum efficiency tends to increase, which is desirable as a phosphor.
Hereinafter, the form of the phosphor of the present invention will be specifically described in detail.

(Weight median diameter D ₅₀ and 4-minute deviation)
The weight median diameter D ₅₀ (hereinafter referred to as “median diameter D ₅₀ ” as appropriate) is defined as follows.
The median diameter D ₅₀ is a value obtained from a weight-based particle size distribution curve. The weight-based particle size distribution curve is obtained by measuring the particle size distribution by a laser diffraction / scattering method. Specifically, it is a value obtained by measuring using CILAS laser diffraction / scattering particle size distribution measuring apparatus model 1064 using water as a dispersion medium. The median diameter D ₅₀ means a particle size value when the integrated value is 50% in this weight-based particle size distribution curve. Similarly, in the weight-based particle size distribution curve, the particle size values when the integrated values are 25% and 75% are denoted as D ₂₅ and D ₇₅ , respectively.

The 4-minute deviation (hereinafter sometimes referred to as “QD”) is defined as QD = (D ₇₅ −D ₂₅ ) / (D ₇₅ + D ₂₅ ). A small value of the 4-minute deviation means that the particle size distribution is narrow.

The phosphor of the present invention usually has a substantially normal particle size distribution, and the median diameter D ₅₀ is preferably 5 μm or more, more preferably 10 μm or more, and preferably 40 μm or less, more preferably 25 μm or less. It is. If the median diameter D ₅₀ is too small, the absorbance of the blue excitation light tends to be low, and it may be difficult to obtain a high-luminance phosphor. On the other hand, when the median diameter D ₅₀ is too large for practical use, it tends to be difficult to use in the nozzle device or the like.

The 4-minute deviation of the particle size of the phosphor of the present invention is usually 0.4 or less, preferably 0.35 or less, particularly preferably 0.30 or less when a phosphor having a single median diameter D ₅₀ is used. It is. As described above, since the phosphor of the present invention has a narrow particle size distribution, it has an effect of high brightness and excellent handleability when a light emitting device is used.
When a plurality of phosphors having different median diameters D ₅₀ are mixed and used in order to increase the light emission efficiency and the light absorption efficiency, the 4-minute deviation in the particle diameter of the mixed phosphor may be larger than 0.4. is there.

(Particle shape / average circularity)
The phosphor of the present invention is preferably closer to a true sphere. The degree of circularity can be used as an index that quantitatively represents the sphericity of the phosphor particles. Here, the degree of circularity is a degree of circularity representing the degree of approximation to a perfect circle of each particle size in a projected view of particles (circularity = perimeter length of a perfect circle equal to the projected area of the particle / perimeter length of the projected particle) Sa)). If it is a perfect sphere, the circularity is 100%. Method of measuring the circularity is measured using a after dispersing the sample as in the case of the weight-average median diameter D ₅₀ of the above-described flow particle image analyzer (manufactured by Sysmex "FPIA-2000").
In addition, it is preferable to remove particles that are extremely large or small in the production of the phosphor, but some contamination is unavoidable in practice. In the phosphor of the present invention, it is preferable to compare the circularity of particles having a particle diameter of 5 μm or more and 30 μm or less, instead of comparing the circularity for the entire range of particle diameters.

  In the phosphor of the present invention, the proportion of particles having a circularity of less than 85% in the particle size distribution of the phosphor particles is usually 4% by number or less, preferably 3% by number or less. The phosphor of the present invention has such a high degree of circularity because this can suppress damage to the phosphor particles by performing the softening treatment in the phosphor manufacturing method of the present invention. . The lower limit of the ratio is ideally 0% by number, but in reality it is 1% by number.

  Moreover, if the average circularity of the phosphor of the present invention is 60% or less, the light emission efficiency of a light emitting device using the phosphor may not be sufficient. Therefore, the average circularity of the phosphor of the present invention is preferably 94% or more, more preferably 95% or more, and more preferably close to 100%. For example, if the surface of the phosphor is damaged or the shape of the phosphor is irregular, such as when broken in the pulverization process, the emission peak intensity tends to decrease, and moreover, it tends to aggregate in the dispersion medium. There is a tendency that uniform light emission is difficult to obtain.

(SEM image)
When the phosphor of the present invention is observed with a scanning electron microscope (SEM), a very beautiful crystal plane is observed. That is, the phosphor of the present invention is composed of particles that exhibit little aggregation between the phosphor particles and that show the original outer shape of the crystal. In addition, the angle formed by the flat portions formed on the surface is usually an obtuse angle, whereby the circularity of the particles approaches 1.
On the other hand, in the conventional phosphor manufactured without performing the softening step, many crystal fracture surfaces are observed. These crushing surfaces often have an acute angle between the surfaces, which contributes to a reduction in the circularity of the particles themselves.
Moreover, the phosphor of the present invention is nearly spherical and has a high ratio of existing as single particles, that is, a single particle formation rate is high.

[2-4. Object color]
The object color of the phosphor of the present invention is not limited. For example, in the case of a phosphor having the chemical composition represented by the above formula [1], the object color is represented by the L ^* a ^* b ^* color system (CIE 1976 table). Expressed in color)
In this case, the L ^* value, a ^* value, and b ^* value satisfy the following expression.
L ^* ≧ 90
a ^* ≦ −20
b ^* ≧ 30

When the phosphor having the chemical composition represented by the formula [1] has an object color that satisfies the above conditions, a light emitting device with high luminous efficiency can be realized when used in the light emitting device.
Specifically, the upper limit value of a ^* of the phosphor having the chemical composition represented by the formula [1] is usually −20 or less, preferably −25 or less, more preferably −30 or less. A phosphor in which a ^* is too large tends to reduce the total luminous flux. Also, from the viewpoint of increasing luminance, it is desirable that the value of a ^* is small.

The phosphor of b ^* is having a chemical composition represented by the formula [1], usually 30 or more, preferably 35 or more, more preferably in the range of 40 or more. If b ^* is too small, the luminance tends to decrease. On the other hand, the upper limit of b ^* is theoretically 200 or less, but is usually preferably 120 or less. If b ^* is too large, the emission wavelength tends to shift to the longer wavelength side and the luminance tends to decrease.

The ratio of a ^* and b ^* of the phosphor having the chemical composition represented by the formula [1], that is, the value represented by a ^* / b ^* is usually −0.45 or less, preferably −0.5. Hereinafter, the range is more preferably −0.55 or less. When the value of a ^* / b ^* is too large, the object color tends to be yellowish and the luminance tends to decrease.

The L ^* of the phosphor having the chemical composition represented by the formula [1] is usually 90 or more, preferably 95 or more, more preferably 100 or more. If the value of L ^* is too small, the light emission tends to be weak. On the other hand, the upper limit of L ^* generally does not exceed 100 because it deals with objects that do not emit light by irradiation light, but the phosphor having the chemical composition represented by the formula [1] is excited by irradiation light. Since the generated light is superimposed on the reflected light, the value of L ^* may exceed 100. Specifically, the upper limit value of L ^* of the phosphor having the chemical composition represented by the formula [1] is usually 115 or less.

The object color of the phosphor can be measured by using, for example, a commercially available object color measuring device (for example, CR-300 manufactured by Minolta).
The object color means a color when light is reflected by the object. In the present invention, an object to be measured (that is, a phosphor) is irradiated with a predetermined light source (white light source, for example, standard light D ₆₅ can be used), and the obtained reflected light is dispersed with a filter. Thus, the values of L ^* , a ^* , and b ^* are obtained.
Object color, the reduction of the phosphor material (e.g., in the case of a phosphor having a chemical composition represented by the formula [1], represented by a molar ratio of bivalent elements to the entire M ^II.) If the degree of reduction is high (for example, in the case of the phosphor having the chemical composition represented by the formula [1], the ratio of the molar ratio of the divalent element to the entire M ^II is high), the above range It is thought that it has the object color. When manufactured according to the method for manufacturing a phosphor of the present invention, such as firing a phosphor material in a strongly reducing atmosphere such as the presence of solid carbon, a phosphor having an object color in the above range can be stably obtained. .

[2-5. Luminescent characteristics]
The phosphor of the present invention has the following characteristics when an emission spectrum is measured when excited with light having a peak wavelength of 400 nm or 455 nm.

・ Emission peak wavelength
The phosphor of the present invention has an emission peak wavelength λp (nm) of usually 400 nm or more, preferably 450 nm or more, more preferably 500 nm or more, and usually 690 nm or less, preferably 680 nm or less, more preferably 670 nm or less. is there. If the emission peak wavelength λ _p is too short or too long, the visibility tends to be low and the luminance tends to decrease.

Among them, the phosphor having the chemical composition represented by the formula [1] has an emission peak wavelength λ _p (nm) of usually 510 nm or more, preferably 518 nm or more, more preferably 520 nm or more, and usually 542 nm or less, preferably The range is 528 nm or less, more preferably 525 nm or less. While the color tends to be bluish green when emission peak wavelength lambda _p is too short, they tend to take on yellowish and that too long, both in some cases the characteristics of the green light decreases.

・ Relative emission peak intensity
The relative intensity of the emission peak of the phosphor of the present invention (hereinafter sometimes referred to as “relative emission peak intensity”) is usually 40 or more, preferably 50 or more, more preferably 60 or more. Among them, the relative emission peak intensity of the phosphor having the chemical composition represented by the formula [1] is usually 75 or more, preferably 85 or more, more preferably 95 or more.
The relative emission peak intensity is higher in the phosphor produced by the phosphor production method of the present invention than in the phosphor produced by the conventional production method. This is considered to be because the phosphor particles were prevented from being damaged by performing the softening step.
Incidentally, the relative emission peak intensity Kasei Optonix Ltd. BaMgAl ₁₀ O _17: Eu represents the emission intensity when the (product number LP-B4) was excited at a wavelength of 365nm light as 100. A higher relative emission peak intensity is preferred.

·Half width
The phosphor of the present invention is not particularly limited in the emission peak half-width (hereinafter referred to as “FWHM” as appropriate) in the emission spectrum. However, the FWHM of the phosphor having the chemical composition represented by the formula [1] is narrow. The narrow FWHM means that the color purity is excellent, and for example, the phosphor is excellent in applications such as a backlight.

  Specifically, the FWHM of the phosphor of the present invention is usually 10 nm or more, preferably 20 nm or more, more preferably 25 nm or more, and usually 130 nm or less, preferably 100 nm or less, more preferably 80 nm or less. Among them, the FWHM of the phosphor having the chemical composition represented by the formula [1] is usually in the range of 10 nm or more, preferably 20 nm or more, more preferably 25 nm or more, and usually 85 nm or less, especially 75 nm or less, and further 70 nm or less. It is. If the FWHM is too narrow, the luminance may decrease. On the other hand, if the FWHM is too wide, the color purity may decrease.

  In order to excite the phosphor with light having a peak wavelength of 400 nm or 455 nm, for example, a GaN-based light emitting diode can be used. Moreover, the measurement of the emission spectrum of the phosphor and the calculation of the emission peak wavelength, the relative emission peak intensity and the peak half width can be performed using, for example, FP-6500 manufactured by JASCO Corporation.

[2-6. Excitation characteristics]
The excitation wavelength of the phosphor of the present invention is not particularly limited, but is usually 300 nm or more, preferably 350 nm or more, more preferably 380 nm or more, and usually 550 nm or less, preferably 500 nm or less, more preferably 480 nm or less. . Among them, the excitation wavelength of the phosphor having the chemical composition represented by the formula [1] is usually 300 nm or more, particularly 350 nm or more, more preferably 380 nm or more, and usually 500 nm or less, especially 480 nm or less, more preferably 470 nm or less. It is preferable that it can be excited by the light. For example, if it can be excited by light in a blue region and / or light in a near ultraviolet region, it can be suitably used for a light emitting device using a semiconductor light emitting element or the like as a first light emitter.

  In addition, the measurement of an excitation spectrum can be measured using FP-6500 by JASCO Corporation at room temperature, for example, 25 degreeC. The excitation peak wavelength can be calculated from the excitation spectrum obtained using the emission peak wavelength when excited with light having a peak wavelength of 400 nm or 455 nm as the monitor wavelength.

[2-7. durability]
The phosphor of the present invention is usually excellent in durability (sustained light emission). Specifically, when it is lit for a long time (for example, 1000 hours) under a high temperature and high humidity condition (for example, an ambient temperature of 85 ° C. and a relative humidity of 85%), it is fluorescent compared to immediately after the start of lighting. This means that the change in intensity of the light emission peak derived from the body is small, that is, the light emission of the phosphor does not decrease even when the light is lit for a long time. This is considered to be an effect obtained by suppressing the damage to the phosphor particles by performing the softening step in the phosphor production method of the present invention.

Among them, the phosphor having the chemical composition represented by the formula [1] is particularly excellent in durability when it contains the ^MIII element.

[2-8. Temperature characteristics]
The phosphor of the present invention is usually excellent in temperature characteristics. This is considered to be an effect obtained by suppressing the damage to the phosphor particles by performing the softening step in the phosphor production method of the present invention. As a specific index, in the emission spectrum when the phosphor of the present invention is irradiated with light having a wavelength of 455 nm, the ratio of the luminance I (100) at 100 ° C. to the luminance I (25) at 25 ° C. is Usually, it is 50% or more, preferably 55% or more, more preferably 60% or more. Among them, the phosphor having the chemical composition represented by the formula [1] is particularly excellent in temperature characteristics by containing an M ^III element such as Tb. Specifically, in the emission spectrum, the ratio of I (100) to I (25) is usually 64% or more, preferably 65% or more, and particularly preferably 66% or more.

  In addition, since the emission intensity of ordinary phosphors decreases with increasing temperature, it is unlikely that the ratio exceeds 100%, but it may exceed 100% for some reason. However, if it exceeds 150%, the color shift tends to occur due to temperature change.

  In the case of measuring the temperature characteristics, for example, an MCPD7000 multi-channel spectrum measuring device manufactured by Otsuka Electronics as a light emission spectrum device, a stage having a cooling mechanism by a Peltier element and a heating mechanism by a heater, and a 150 W xenon lamp as a light source. It can measure as follows using the apparatus provided. A cell containing a phosphor sample is placed on the stage, and the temperature is changed in the range of 20 ° C to 180 ° C. It is confirmed that the surface temperature of the phosphor is constant at a predetermined temperature. Next, the emission spectrum is measured by exciting the phosphor with light having a wavelength of 455 nm extracted from the light source by the diffraction grating. From the measured emission spectrum, the luminance is determined in accordance with JIS 27824 in a wavelength region where excitation light is not mixed (specifically, 480 nm or more and 780 nm or less). Here, as the measurement value of the surface temperature of the phosphor, a value corrected using the temperature measurement value by the radiation thermometer and the thermocouple is used.

[2-9. Quantum efficiency]
The absorption efficiency (hereinafter sometimes referred to as “α _q ”) is determined by the fact that the phosphor is less than the number of photons of light (excitation light) emitted by the excitation light source (corresponding to “first illuminant” described later). It means the ratio of the number of photons absorbed. In the following description, “photon” may be referred to as “photon”.
Further, the internal quantum efficiency (hereinafter sometimes expressed as “η _i ”) means the ratio of the number of photons emitted by the phosphor to the number of photons of the excitation light absorbed by the phosphor.
Furthermore, (which may be expressed by the following "eta _o".) External quantum efficiency is a value representing the ratio of the emission photon number of the phosphor against the photon number of the excitation light, wherein the said absorption efficiency alpha _q Is equivalent to the product of the internal quantum efficiency η _i of. That is, the external quantum efficiency η _o is defined by the following equation.
(External quantum efficiency η _o ) = (internal quantum efficiency η _i ) × (absorption efficiency α _q )

The phosphor of the present invention usually has a high quantum efficiency such as the above-described absorption efficiency α ₀ , internal quantum efficiency η _i, and external quantum efficiency η _o . This is considered to be an effect obtained by suppressing the damage to the phosphor particles by performing the softening step in the phosphor production method of the present invention.

Specifically, the absorption efficiency α _q when the phosphor of the present invention is excited with light having a peak wavelength of 400 nm or 455 nm is usually 0.4 or more, preferably 0.5 or more, more preferably 0.6 or more. is there. Among them, the absorption efficiency α _q of the phosphor having the chemical composition represented by the formula [1] is desirably 0.55 or more, preferably 0.6 or more, more preferably 0.75 or more. If the absorption efficiency α _q of the phosphor is too low, the amount of excitation light necessary to obtain the predetermined light emission tends to increase and the energy consumption tends to increase.

Further, when the phosphor of the present invention is excited with light having a peak wavelength of 400 nm or 455 nm, the internal quantum efficiency η _i is usually 0.4 or more, preferably 0.45 or more, more preferably 0.5 or more. Among these, the internal quantum efficiency η _i of the phosphor having the chemical composition represented by the formula [1] is desirably 0.57 or more, preferably 0.69 or more, more preferably 0.79 or more. If the internal quantum efficiency η _i of the phosphor is too low, the amount of excitation light necessary to obtain predetermined light emission tends to increase and the energy consumption tends to increase.

Furthermore, the external quantum efficiency η _o when the phosphor of the present invention is excited with light having a peak wavelength of 400 nm or 455 nm is usually 0.3 or more, preferably 0.4 or more, more preferably 0.5 or more. Among these, the external quantum efficiency η _o of the phosphor having the chemical composition represented by the formula [1] is usually 0.42 or more, preferably 0.50 or more, more preferably 0.55 or more, and further preferably 0.65. That's it. When the external quantum efficiency η _o of the phosphor is low, the amount of excitation light necessary for obtaining predetermined light emission tends to increase and the energy consumption tends to increase.

(Measurement method of absorption efficiency α _q , internal quantum efficiency η _i , and external quantum efficiency η _o )
A method for obtaining the absorption efficiency α _q , internal quantum efficiency η _i and external quantum efficiency η _o of the phosphor will be described below.

  First, a phosphor sample to be measured (for example, a phosphor powder) is packed in a cell with a sufficiently smooth surface so that measurement accuracy is maintained, and is attached to a condenser such as an integrating sphere. The use of a condenser such as an integrating sphere makes it possible to count all the photons reflected by the phosphor sample and the photons emitted from the phosphor sample due to the fluorescence phenomenon. This is to eliminate the photons that fly away.

  A light emission source for exciting the phosphor sample is attached to the light collecting device. For example, an Xe lamp or the like is used as the light source. Further, adjustment is performed using a filter, a monochromator (diffraction grating spectrometer), or the like so that the emission peak wavelength of the light emission source is monochromatic light of, for example, 405 nm or 455 nm.

The phosphor sample to be measured is irradiated with light from the light emission source whose emission peak wavelength is adjusted, and a spectrum including light emission (fluorescence) and reflected light is measured with a spectrometer (for example, MCPD7000 manufactured by Otsuka Electronics Co., Ltd.). taking measurement. The spectrum measured here is actually reflected light that has not been absorbed by the phosphor among the light from the excitation light source (hereinafter simply referred to as “excitation light”), and the phosphor is excited light. And other wavelengths of light (fluorescence) emitted by the fluorescence phenomenon. That is, the excitation light region corresponds to the reflection spectrum, and the longer wavelength region corresponds to the fluorescence spectrum (sometimes referred to herein as the emission spectrum).

The absorption efficiency α _q is obtained as a value obtained by dividing the number of photons _Nabs of the excitation light absorbed by the phosphor sample by the total number of photons N of the excitation light. The specific calculation procedure is as follows.

First, the total photon number N of the latter excitation light is obtained as follows.
That is, a white reflection plate such as a substance having a reflectance R of almost 100% with respect to excitation light, for example, “Spectralon” manufactured by Labsphere (having a reflectance R of 98% with respect to excitation light of 450 nm) is measured. As described above, the light-emitting device is attached to the above-described condensing device in the same arrangement as the phosphor sample, and the reflection spectrum is measured using the spectroscopic measurement device (this reflection spectrum is hereinafter referred to as “I _ref (λ)”).

From this reflection spectrum I _ref (λ), a numerical value represented by the following (formula A) is obtained. The numerical value represented by the following (formula A) is proportional to the total photon number N of the excitation light.

It should be noted that the integration interval of the above (formula A) may be limited to only an interval where I _ref (λ) has a significant value.

On the other hand, number N _abs of the photons in the excitation light that is absorbed in the phosphor sample is proportional to the amount calculated by the following equation (B).

In the above (Formula B), "I (lambda)" represents the reflection spectrum when fitted with a phosphor sample to be measured of the absorption efficiency alpha _q to condenser.

  Further, the integration interval of the above (formula B) is made the same as the integration interval defined by the above (formula A). By limiting the integration interval in this way, the second term of the above (formula B) is a numerical value corresponding to the number of photons generated when the phosphor sample to be measured reflects the excitation light, that is, the measurement target. This is a numerical value corresponding to the number of photons excluding photons derived from the fluorescence phenomenon among all photons generated from the phosphor sample. Since the actual spectrum measurement value is generally obtained as digital data divided by a certain finite bandwidth with respect to λ, the integration of (Equation A) and (Equation B) above is based on the sum based on the bandwidth. I want.

From the above, the absorption efficiency α _q can be obtained by the following equation.
Absorption efficiency α _q = N _abs / N = (Formula B) / (Formula A)

Next, a method for obtaining the internal quantum efficiency η _i will be described.
Internal quantum efficiency eta _i is a number N _PL of photons originating from the fluorescence phenomenon, divided by the number N _abs of photons phosphor sample has absorbed.

Here, N _PL is proportional to the amount obtained by the following (formula C).

Note that the integration interval of the above (formula C) is limited to the wavelength range of photons derived from the fluorescence phenomenon of the phosphor sample. This is because the contribution of photons reflected from the phosphor sample is removed from I (λ).
Specifically, the lower limit of the integration interval of (Equation C) takes the upper end of the integration interval of (Equation A), and the upper limit of the integration interval is a range that is necessary and sufficient to include photons derived from fluorescence. To do.

As described above, the internal quantum efficiency α _q is obtained by the following equation.
η _i = (Formula C) / (Formula B)

It should be noted that the point of integration from the spectrum that has become digital data is the same as when the absorption efficiency α _q is obtained.

The external quantum efficiency η _o can be obtained by taking the product of the absorption efficiency α _q obtained by the above procedure and the internal quantum efficiency η _i .

The external quantum efficiency η _o can also be obtained from the following relational expression.
η _o = (Formula C) / (Formula A)
That is, the external quantum efficiency η _o is a value obtained by dividing the number of photons N _PL derived from fluorescence by the total number of photons N of excitation light.

[3. Phosphor with low Ca content]
The other phosphor of the present invention is not necessarily manufactured by the phosphor manufacturing method of the present invention, except that [2. Of the phosphor of the present invention is described in the section of the phosphor, a phosphor having a chemical composition represented by the formula [1], when the two the sum of the M ^I and M ^II, M ^I and The value of the molar ratio of Ca to the total of M ^II is usually 0.005 or less, preferably 0.0005 or less, more preferably 0.0002 or less, and usually 0.000001 or more, preferably 0.000005 or more, more Preferably it is the same as that of the range of 0.00001 or more.
That is, another phosphor of the present invention is a phosphor having at least an alkaline earth metal element as a part of a host crystal and having an orthosilicate or garnet crystal structure, and has a circularity of 85%. The proportion of particles less than 4 is 4% by number or less, the value of QD is 0.4 or less, the chemical composition is represented by the formula [1], M ^I contains at least Ca, and M ^I and when two of the sum of M ^II, the value of Ca molar ratio of to the total of M ^I and M ^II is 0.005 or less, a phosphor is 0.000001 or more.
However, you may manufacture another fluorescent substance of this invention with the manufacturing method of the fluorescent substance of this invention.

  This another phosphor of the present invention has improved luminance as compared with the conventional phosphor.

[4. Phosphor-containing composition]
[2. Phosphor] or [3. Any of the phosphors of the present invention described in the section “Fluorescent substance with low Ca content” 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, sealed and then cured by heat or light. 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.

[4-1. 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, the phosphor-containing composition of the present invention may contain a phosphor other than the phosphor of the present invention as long as the effects of the present invention are not significantly impaired.

[4-2. 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 an inorganic material (for example, an inorganic material having a siloxane bond). System materials) and the like.

  Examples of organic materials include thermoplastic resins, thermosetting resins, and photocurable resins. Specific examples include methacrylic resins such as methyl polymethacrylate; styrene resins such as polystyrene and styrene-acrylonitrile copolymers; polycarbonate resins; polyester resins; phenoxy resins; butyral resins; polyvinyl alcohols; Cellulose-based resins such as cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins.

  Among these, in particular, when the phosphor of the present invention is used in a light-emitting device having a high output such as illumination, it is preferable to use a silicon-containing compound as a liquid medium for the purpose of improving heat resistance, light resistance and the like.

  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. And glass materials such as phosphosilicate and alkali silicate. Among these, silicone materials are preferable from the viewpoint of ease of handling.

The silicone material generally refers to an organic polymer having a siloxane bond as a main chain, and examples thereof include a compound represented by the general composition formula (i) and / or a mixture thereof.
(R ¹ R ² R ³ SiO _1/2 ) _M (R ⁴ R ⁵ SiO _2/2 ) _D (R ⁶ SiO _3/2 ) _T (SiO _4/2 ) _Q Formula (i)
In the general composition formula (i), R ¹ to R ⁶ represent those selected from the group consisting of organic functional groups, hydroxyl groups, and hydrogen atoms. R ¹ to R ⁶ may be the same or different.
In the above formula (i), M, D, T, and Q are numbers that are 0 or more and less than 1, respectively, and that satisfy M + D + T + Q = 1.

  When used for sealing a semiconductor light emitting device, the silicone material can be used after being sealed with a liquid silicone material and then cured by heat or light.

  When silicone materials are classified according to the curing mechanism, silicone materials such as an addition polymerization curing type, a condensation polymerization curing type, an ultraviolet curing type, and a peroxide vulcanization type can be generally cited. Among these, addition polymerization curing type (addition type silicone material), condensation curing type (condensation type silicone material), and ultraviolet curing type are preferable. Hereinafter, the addition type silicone material and the condensation type silicone material will be described.

  The addition-type silicone material refers to a material in which polyorganosiloxane chains are crosslinked by organic addition bonds. Typical examples include compounds having a Si—C—C—Si bond at the crosslinking point obtained by reacting vinylsilane and hydrosilane in the presence of an addition catalyst such as a Pt catalyst. As these, commercially available products can be used. Specific examples of addition polymerization curing type trade names include “LPS-1400”, “LPS-2410”, and “LPS-3400” manufactured by Shin-Etsu Chemical Co., Ltd.

  On the other hand, examples of the condensation type silicone material include a compound having a Si—O—Si bond obtained by hydrolysis and polycondensation of an alkylalkoxysilane at a crosslinking point. Specific examples thereof include polycondensates obtained by hydrolysis and polycondensation of compounds represented by the following general formula (ii) and / or (iii) and / or oligomers thereof.

M ^{m +} X _n Y ¹ _mn (ii)
(In formula (ii), M represents at least one element selected from silicon, aluminum, zirconium, and titanium, X represents a hydrolyzable group, and Y ¹ represents a monovalent organic group. M represents one or more integers representing the valence of M, and n represents one or more integers representing the number of X groups, provided that m ≧ n.

_{^{(M s + X t Y 1}} st-1) u Y 2 (iii)
(In formula (iii), M represents at least one element selected from silicon, aluminum, zirconium, and titanium, X represents a hydrolyzable group, and Y ¹ represents a monovalent organic group. Y ² represents a u-valent organic group, s represents an integer of 1 or more representing the valence of M, t represents an integer of 1 or more and s−1 or less, and u is Represents an integer of 2 or more.)

  Further, the condensation type silicone material may contain a curing catalyst. As this curing catalyst, for example, a metal chelate compound or the like can be suitably used. The metal chelate compound preferably contains one or more of Ti, Ta, and Zr, and more preferably contains Zr. In addition, only 1 type may be used for a curing catalyst and it may use 2 or more types together by arbitrary combinations and a ratio.

  Examples of such condensation type silicone materials include members for semiconductor light emitting devices described in JP-A Nos. 2007-112973 to 112975, JP-A No. 2007-19459, and Japanese Patent Application No. 2006-176468. Is preferred.

Of the condensed silicone materials, particularly preferred materials will be described below.
Silicone-based materials generally have a problem of poor adhesion to semiconductor light-emitting elements, substrates on which the elements are arranged, packages, and the like, but as silicone-based materials having high adhesion, the following features [1] to A condensation type silicone material having one or more of [3] is preferred.

[1] The silicon content is 20% by weight or more.
[2] The solid Si-nuclear magnetic resonance (NMR) spectrum measured by the method described in detail later has at least one peak derived from Si in the following (a) and / or (b).
(A) A peak whose peak top position is in a region where the chemical shift is −40 ppm or more and 0 ppm or less with respect to tetramethoxysilane, and the half width of the peak is 0.3 ppm or more and 3.0 ppm or less.
(B) A peak whose peak top position is in a region where the chemical shift is −80 ppm or more and less than −40 ppm with respect to tetramethoxysilane, and the half width of the peak is 0.3 ppm or more and 5.0 ppm or less.
[3] The silanol content is 0.1% by weight or more and 10% by weight or less.

In the present invention, among the above features [1] to [3], a silicone material having the feature [1] is preferable, a silicone material having the above features [1] and [2] is more preferable, Particularly preferred are silicone materials having all the features [1] to [3].
Hereinafter, the above features [1] to [3] will be described.

[4-2-1. Feature [1] (silicon content)]
The basic skeleton of conventional silicone materials is an organic resin such as an epoxy resin having carbon-carbon and carbon-oxygen bonds as the basic skeleton, whereas the basic skeleton of silicone materials suitable for the present invention is glass (silica). It is the same inorganic siloxane bond as acid glass). As apparent from the chemical bond comparison table shown in Table 2 below, this siloxane bond has the following characteristics excellent as a silicone material.

(I) Since the binding energy is large and thermal decomposition and photolysis are difficult, light resistance is good.
(II) It is slightly polarized electrically.
(III) The degree of freedom of the chain structure is large, a structure with high flexibility is possible, and the chain structure can freely rotate around the center of the siloxane chain.
(IV) The degree of oxidation is large and no further oxidation occurs.
(V) Rich in electrical insulation.

  Because of these characteristics, silicone-based silicone materials that are formed with a skeleton in which siloxane bonds are three-dimensionally bonded with a high degree of crosslinking are close to inorganic materials such as glass or rock, and have a high heat resistance and light resistance. Can be understood. In particular, a silicone-based material having a methyl group as a substituent has no absorption in the ultraviolet region, so that photolysis hardly occurs and has excellent light resistance.

The silicon content of the silicone material suitable for the present invention is usually 20% by weight or more, preferably 25% by weight or more, and more preferably 30% by weight or more. On the other hand, the upper limit is usually in the range of 47% by weight or less because the silicon content of the glass composed solely of SiO ₂ is 47% by weight.

Note that the silicon content of the silicone-based material is measured by, for example, inductively coupled plasma spectrum using the following method.
ometry: hereinafter abbreviated as “ICP” as appropriate ) Analysis can be performed and calculated based on the result.

{Measurement of silicon content}
Silicone material is baked in a platinum crucible in the air at 450 ° C. for 1 hour, then at 750 ° C. for 1 hour, and at 950 ° C. for 1.5 hours to remove the carbon component, and then a small amount of residue is obtained. Add more than 10 times the amount of sodium carbonate and heat with a burner to melt, cool this, add demineralized water, and adjust the pH to neutral with hydrochloric acid to a few ppm as silicon. ICP analysis is performed.

[4-2-2. Feature [2] (Solid Si-NMR Spectrum)]
When a solid Si-NMR spectrum of a silicone-based material suitable for the present invention is measured, at least one peak in the peak region of (a) and / or (b) derived from a silicon atom to which a carbon atom of an organic group is directly bonded, Preferably, a plurality of peaks are observed.

When arranged for each chemical shift, in the silicone-based material suitable for the present invention, the half width of the peak described in (a) is generally less than the peak described in (b) described later because molecular motion is less restricted. It is smaller than the case, usually in the range of 3.0 ppm or less, preferably 2.0 ppm or less, and usually 0.3 ppm or more.
On the other hand, the full width at half maximum of the peak described in (b) is usually 5.0 ppm or less, preferably 4.0 ppm or less, and usually 0.3 ppm or more, preferably 0.4 ppm or more.

  If the half-value width of the peak observed in the chemical shift region is too large, the molecular motion is constrained and the strain becomes large, cracks are likely to occur, and the member may be inferior in heat resistance and weather resistance. For example, when a large amount of tetrafunctional silane is used, or when a large internal stress is accumulated by rapid drying in the drying process, the half width range becomes larger than the above range.

  In addition, if the half width of the peak is too small, Si atoms in the environment will not be involved in siloxane crosslinking, and heat resistance is higher than that of substances formed mainly from siloxane bonds, such as cases where trifunctional silane remains in an uncrosslinked state. -It may be a member inferior in weather resistance.

  However, in a silicone material containing a small amount of Si component in a large amount of organic component, good heat resistance / light resistance and coating performance can be obtained even if the peak of the above-mentioned half-value range is observed at -80 ppm or more. There may not be.

  The value of the chemical shift of the silicone material suitable for the present invention can be calculated based on the results of solid Si-NMR measurement using the following method, for example. In addition, analysis of measurement data (half-width or silanol amount analysis) is performed by a method of dividing and extracting each peak by, for example, waveform separation analysis using a Gaussian function or a Lorentz function.

{Solid Si-NMR spectrum measurement and silanol content calculation}
When performing a solid Si-NMR spectrum about a silicone type material, a solid Si-NMR spectrum measurement and waveform separation analysis are performed on condition of the following. Further, from the obtained waveform data, the half width of each peak is determined for the silicone material. Also, from the ratio of the peak area derived from silanol to the total peak area, the ratio (%) of silicon atoms that are silanols in all silicon atoms is obtained, and the silanol content is determined by comparing with the silicon content analyzed separately. Ask.

{Device conditions}
Apparatus: Chemmagnetics Infinity CMX-400 Nuclear magnetic resonance spectrometer
²⁹ Si resonance frequency: 79.436 MHz
Probe: 7.5mmφCP / MAS probe
Measurement temperature: room temperature
Sample rotation speed: 4 kHz
Measurement method: Single pulse method
¹ H decoupling frequency: 50 kHz
²⁹ Si flip angle: 90 °
²⁹ Si 90 ° pulse width: 5.0μs
Repeat time: 600s
Integration count: 128 times
Observation width: 30 kHz
Broadening factor: 20Hz
Reference sample: Tetramethoxysilane

  For silicone-based materials, 512 points are taken as measurement data, zero-filled to 8192 points, and Fourier transformed.

{Waveform separation analysis method}
For each peak of the spectrum after Fourier transform, optimization calculation is performed by a non-linear least square method with the center position, height, and half width of the peak shape created by Lorentz waveform and Gaussian waveform or a mixture of both as variable parameters.
For peak identification, refer to AIChE Journal, 44 (5), p.1141, 1998, etc.

[4-2-3. Feature [3] (silanol content)]
The silicone material suitable for the present invention has a silanol content of usually 0.1% by weight or more, preferably 0.3% by weight or more, and usually 10% by weight or less, preferably 8% by weight or less, more preferably The range is 5% by weight or less. By reducing the silanol content, the silanol-based material has excellent performance with little change over time, excellent long-term performance stability, and low moisture absorption and moisture permeability. However, since a member containing no silanol is inferior in adhesion, there exists an optimum range for the silanol content as described above.

  The silanol content of the silicone material is, for example, the above [4-2-2. The solid Si-NMR spectrum was measured using the method described in the section {Characteristic [2] (Solid Si-NMR spectrum)} {Solid Si-NMR spectrum measurement and silanol content calculation}. It can be calculated by obtaining the ratio (%) of silicon atoms that are silanols in all silicon atoms from the ratio of the peak area derived from and comparing with the silicon content analyzed separately.

  In addition, since the silicone-based material suitable for the present invention contains an appropriate amount of silanol, the silanol usually bonds with hydrogen at the polar portion present on the device surface, thereby exhibiting adhesion. Examples of the polar part include a hydroxyl group and a metalloxane-bonded oxygen.

  In addition, the silicone material suitable for the present invention is usually heated in the presence of an appropriate catalyst to form a covalent bond by dehydration condensation with the hydroxyl group on the device surface, thereby exhibiting stronger adhesion. can do.

On the other hand, if there is too much silanol, the inside of the system will thicken and it will be difficult to apply, or it will become more active and solidify before the light-boiling components volatilize by heating, leading to increased foaming and internal stress. It may occur and induce cracks.

[4-3. 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 there is too little liquid medium, there is a possibility that it will be difficult to handle due to lack of fluidity.

  The liquid medium mainly has a role as a binder in the phosphor-containing composition of the present invention. Only one type of liquid medium may be used, but two or more types may be used 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.

[4-4. Other ingredients]
The phosphor-containing composition of the present invention may contain other components in addition to the phosphor and the liquid medium as long as the effects of the present invention are not significantly impaired. 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.

[4-5. Advantages of phosphor-containing composition]
According to the phosphor-containing composition of the present invention, the phosphor of the present invention can be easily fixed at a desired position. For example, when the phosphor-containing composition of the present invention is used in the production of a light-emitting device, the phosphor-containing composition of the present invention is molded at a desired position and the liquid medium is cured. The phosphor can be sealed, and the phosphor of the present invention can be easily fixed at a desired position.

[5. Light emitting device]
A light-emitting device of the present invention is a light-emitting device that includes a first light-emitting body (excitation light source) and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body. The above-mentioned [2. Phosphor] or [3. The phosphor of the present invention described in the section of “phosphor with low Ca content” is contained as the first phosphor.

Specifically, the light-emitting device of the present invention uses an excitation light source as will be described later as the first light emitter, adjusts the type and proportion of the phosphor used as the second light emitter, and is a known device configuration By arbitrarily taking, a light emitting device that emits light in any color can be manufactured.
For example, a white light emitting device is manufactured by combining an excitation light source that emits blue light, a phosphor that emits green fluorescence (green phosphor), and a phosphor that emits orange or red fluorescence (orange or red phosphor). be able to. The emission color in this case can be changed to a desired emission color by adjusting the emission wavelength of the phosphor of the present invention or the combined orange or red phosphor. For example, so-called pseudo white (for example, blue LED and It is also possible to obtain an emission spectrum similar to the emission spectrum of the light emitting device combined with a yellow phosphor. Furthermore, combining this white light-emitting device with a phosphor that emits red fluorescence (red phosphor) realizes a light-emitting device that excels in red color rendering and a light-emitting device that emits light bulb color (warm white). can do. Also, a white light emitting device can be manufactured by combining an excitation light source that emits near-ultraviolet light with a phosphor that emits blue fluorescence (blue phosphor), a green phosphor, and a red phosphor.

  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 Z 8701 Of these, white is preferred.

Furthermore, if necessary, yellow phosphors (phosphors that emit yellow fluorescence), blue phosphors, orange to red phosphors, other types of green phosphors, etc. It is also possible to manufacture a light emitting device that adjusts and emits light in an arbitrary color.
Only one kind of the phosphor of the present invention may be used, or two or more kinds may be used in any combination and ratio.

  In the emission spectrum of the light emitting device of the present invention, the emission peak in the green region preferably has an emission peak in the wavelength range of 515 nm to 535 nm, and the emission peak in the red region has an emission peak in the wavelength range of 580 nm to 680 nm. Those having a light emission peak in the wavelength range of 430 nm to 480 nm as the light emission peak in the blue region are preferable, and those having a light emission peak in the wavelength range of 540 nm to 580 nm as the light emission peak in the yellow region are preferable.

  Note that the emission spectrum of the light emitting device is measured by energizing 20 mA with a color / illuminance measurement software and USB2000 series spectroscope (integral sphere specification) manufactured by Ocean Optics in a room maintained at a temperature of 25 ± 1 ° C. It can be carried out. Chromaticity values (x, y, z) can be calculated as chromaticity coordinates in the XYZ color system defined by JIS Z8701 from data in the wavelength region of 380 nm to 780 nm of the emission spectrum. In this case, the relational expression x + y + z = 1 holds. In the present specification, the XYZ color system may be referred to as an XY color system, and is usually expressed as (x, y).

  The luminous efficiency is obtained by obtaining the total luminous flux from the result of the emission spectrum measurement using the light emitting device as described above, and dividing the lumen (lm) value by the power consumption (W). The power consumption is obtained by measuring a voltage using a True RMS Multimeters Model 187 & 189 manufactured by Fluke in a state in which 20 mA is energized, and obtaining the product of the current value and the voltage value.

[5-1. Configuration of Light Emitting Device (Light Emitter)]
(First luminous body)
The 1st light-emitting body in the light-emitting device of this invention light-emits the light which excites the 2nd light-emitting body mentioned later.

  The light emission wavelength of the first light emitter is not particularly limited as long as it overlaps with the absorption wavelength of the second light emitter described later, and a light emitter having a wide light emission wavelength region can be used. Usually, an illuminant having an emission wavelength from the ultraviolet region to the blue region is used, and it is particularly preferable to use an illuminant having an emission wavelength from the near ultraviolet region to the blue region.

  As a specific numerical value of the emission peak wavelength of the first illuminant, 200 nm or more is usually desirable. Among these, when near-ultraviolet light is used as excitation light, it is usually 300 nm or more, preferably 330 nm or more, more preferably 360 nm or more, and a light emitter having an emission peak wavelength of usually 420 nm or less is used. desirable. When blue light is used as excitation light, it is usually 420 nm or more, preferably 430 nm or more, and it is desirable to use a light emitter having an emission peak wavelength of usually 500 nm or less, preferably 480 nm or less. Both are from the viewpoint of color purity of the light emitting device.

As the first light emitter, a semiconductor light emitting element is generally used, specifically a light emitting LED.
And a semiconductor laser diode (hereinafter, abbreviated as “LD” as appropriate) 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 LED or LD using a GaN compound semiconductor is preferable. This is because GaN-based LEDs and LDs have significantly higher light emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely bright with very low power when combined with the phosphor. This is because light emission can be obtained. For example, for a current load of 20 mA, GaN-based LEDs and LDs usually have a light emission intensity 100 times or more that of SiC-based. GaN-based LEDs and LDs preferably have an Al _x Ga _y N light emitting layer, a GaN light emitting layer, or an In _x Ga _y N light emitting layer. Among GaN-based LEDs, those having an In _X Ga _Y N light-emitting layer are particularly preferable because of their very high emission intensity. In GaN-based LEDs, a multiple quantum well structure of In _X Ga _Y N layers and GaN layers is preferred. Is particularly preferable because the emission intensity is very strong.

  In the above, the value of X + Y is usually a value in the range of 0.8 to 1.2. In the GaN-based LED, those in which the light emitting layer is doped with Zn or Si or those without a dopant are preferable for adjusting the light emission characteristics.

A GaN-based LED has these light-emitting layer, p-layer, n-layer, electrode, and substrate as basic components, and the light-emitting layer is composed of n-type and p-type Al _x Ga _y N layers, GaN layers, or In _x. Those having a hetero structure sandwiched by Ga _Y N layers or the like are preferable because of high light emission efficiency, and those having a hetero structure having a quantum well structure are more preferable because of high light emission efficiency.
Note that only one first light emitter may be used, or two or more first light emitters may be used in any combination and ratio.

(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 contains the phosphor of the present invention described above as the first phosphor. In addition, a second phosphor (an orange to red phosphor, a green phosphor, a blue phosphor, a yellow phosphor, etc.), which will be described later, is contained as appropriate according to the application. Further, for example, the second light emitter is configured by dispersing the first and second phosphors in a sealing material.

There is no restriction | limiting in particular in the composition of fluorescent substance other than the fluorescent substance of this invention used in the said 2nd light-emitting body. For example, metal oxides represented by Y ₂ O ₃ , YVO ₄ , Zn ₂ SiO ₄ , Y ₃ Al ₅ O ₁₂ , Sr ₂ SiO _4, etc., which become the crystal matrix, Sr ₂ Si ₅ N ₈ Metal nitrides typified by, etc., phosphates typified by Ca ₅ (PO ₄ ) ₃ Cl, etc. and sulfides typified by ZnS, SrS, CaS, etc., Y ₂ O ₂ S, La ₂ O ₂ S Ions of rare earth metals such as Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, Ag, Cu, Au, Al, Mn, What combined the ion of metals, such as Sb, as an activator element or a coactivator element is mentioned.

Preferred examples of the crystal matrix include, for example, sulfides such as (Zn, Cd) S, SrGa ₂ S ₄ , SrS, ZnS; oxysulfides such as Y ₂ O ₂ S; (Y, Gd) ₃ Al ₅ O ₁₂ , YAlO ₃ , Ba MgAl ₁₀ O ₁₇ , (Ba, Sr) (Mg, Mn) Al ₁₀ O ₁₇ , (Ba, Sr, Ca) (Mg, Zn, Mn) Al ₁₀ O ₁₇ , BaAl ₁₂ O ₁₉ , Aluminates such as CeMgAl ₁₁ O ₁₉ , (Ba, Sr, Mg) O.Al ₂ O ₃ , BaAl ₂ Si ₂ O ₈ , SrAl ₂ O ₄ , Sr ₄ Al ₁₄ O ₂₅ , Y ₃ Al ₅ O ₁₂ ; Silicates such as Y ₂ SiO ₅ and Zn ₂ SiO ₄ ; oxides such as SnO ₂ and Y ₂ O ₃
Borate salts such as GdMgB ₅ O ₁₀ and (Y, Gd) BO ₃ ; Ca ₁₀ (PO ₄ ) ₆ (F, Cl) ₂ , (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl _{2 and the} like And phosphates such as Sr ₂ P ₂ O ₇ and (La, Ce) PO ₄ .

  However, the above-mentioned crystal matrix, activator element and coactivator element are not particularly limited in element composition, and can be partially replaced with elements of the same family, and the obtained phosphor is light in the near ultraviolet to visible region. Any material that absorbs and emits visible light can be used.

  Specifically, the following phosphors can be used, but these are merely examples, and phosphors that can be used in the present invention are not limited to these. In the following examples, as described above, phosphors that differ only in part of the structure are omitted as appropriate.

(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, or two or more 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. For example, when the phosphor of the present invention is a green phosphor, another type of green phosphor can be used together with the phosphor of the present invention as the first phosphor. In the case of an orange or red phosphor, as the first phosphor, another type of orange or red phosphor can be used together with the phosphor of the present invention. When the phosphor of the present invention is a blue phosphor, Can be used together with the phosphor of the present invention in combination with another type of blue phosphor, and when the phosphor of the present invention is a yellow phosphor, the first phosphor Other types of yellow phosphors can be used in combination with the phosphor of the present invention.
Any phosphor can be used as long as the effects of the present invention are not significantly impaired.

(Green phosphor)
The emission peak wavelength of the green phosphor is usually 500 nm or more, preferably 510 nm or more, more preferably 515 nm or more, and is usually 550 nm or less, particularly 542 nm or less, more preferably 535 nm or less. If this emission peak wavelength λp is too short, it tends to be bluish, while if it is too long, it tends to be yellowish, and there is a possibility that the characteristics as green light will deteriorate.

  In addition, the half-value width of the emission peak of the green phosphor is usually 10 nm or more and usually 130 nm or less, and is preferably adjusted as appropriate according to the application. If the full width at half maximum FWHM is too narrow, the emission intensity may decrease, and if it is too wide, the color purity may decrease.

The green phosphor, the external quantum efficiency is usually 60% or more, preferably more than 70%, the median diameter D ₅₀ is usually 1μm or more, preferably 5μm or more, more preferably 10mμ more usually It is 30 μm or less, preferably 20 μm or less, more preferably 15 μm or less.

As a specific example of the green phosphor, europium activation represented by (Mg, Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu that is composed of fractured particles having a fracture surface and emits light in the green region. Examples thereof include alkaline earth silicon oxynitride phosphors.

Other green phosphors include Eu-activated aluminate phosphors such as Sr ₄ Al ₁₄ O ₂₅ : Eu, (Ba, Sr, Ca) Al ₂ O ₄ : Eu, and (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, Ce, Tb activated silicate phosphor such as Tb, Sr ₂ P ₂ O ₇ —Sr ₂ B ₂ O ₅ : Eu activated borate phosphate phosphor such as Eu, Sr 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} , ₃ Al ₅ O _12: Tb-activated aluminate phosphors such as _{Tb, Ca 2 Y 8 (SiO} 4) 6 O 2: Tb, La 3 Ga 5 SiO 14: Tb -activated silicate phosphors such as Tb, (Sr, Ba, Ca) Ga ₂ S ₄ : Eu, Tb, Sm activated thiogallate phosphors 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 phosphor such as Ce, Ce activated oxide phosphor such as CaSc ₂ O ₄ : Ce, Eu activated oxynitride phosphor such as Eu activated β sialon _{, BaMgAl 10 O 17: Eu,} Eu such as Mn, Mn-activated aluminate phosphor, SrAl ₂ O _4: Eu such as Eu Activated aluminate phosphors, (La, Gd, Y) 2 O 2 S: Tb Tsukekatsusan sulfide phosphor such as Tb, LaPO _4: Ce, Ce and Tb such, Tb-activated phosphate phosphor, Sulfide phosphors such as ZnS: Cu, Al, ZnS: Cu, Au, 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 Eu, Mn activated halosilicate phosphors such as (Sr, Ca, Ba) (Al, Ga, In) ₂ S ₄ : Eu activated thioaluminate phosphors and thiogallate phosphors such as Eu, (Ca, Sr) ₈ (Mg, Zn) (SiO ₄ ) ₄ Cl ₂ : Eu, Mn activated halosilicate phosphor such as Eu, Mn, M ₃ S i 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

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

(Orange to red phosphor)
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.

Examples of such orange to red phosphors include europium represented by (Mg, Ca, Sr, Ba) ₂ Si ₅ N ₈ : Eu that is composed of fractured particles having a red fracture surface and emits light in the red region. The activated alkaline earth silicon nitride phosphor is composed of growing particles having a substantially spherical shape as a regular crystal growth shape, and emits light in the red region (Y, La, Gd, Lu) ₂ O ₂ S: Eu And europium activated rare earth oxychalcogenide phosphors represented by the formula:

In addition, the half-value width of the emission peak of the red phosphor is usually in the range of 1 nm to 100 nm.
The red phosphor has an external quantum efficiency of usually 60% or more, preferably 70% or more, and a median diameter D ₅₀ is usually 1 μm or more, preferably 5 μm or more, more preferably 10 mμ or more. It is 30 μm or less, preferably 20 μm or less, more preferably 15 μm or less.

  Furthermore, an oxynitride and / or an acid containing at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, W, and Mo described in JP-A No. 2004-300247 A phosphor containing a sulfide and 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, examples of red phosphors include Eu-activated oxysulfide phosphors such as (La, Y) ₂ O ₂ S: Eu, Y (V, P) O ₄ : Eu, Y ₂ O ₃ : Eu, and the like. Eu-activated oxide phosphor, (Ba, Mg) ₂ SiO ₄ : Eu, Mn, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, Mn-activated silicate phosphor such as Eu, Mn, Eu-activated tungstate phosphors such as 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 : Sm Eu-activated sulfide phosphors such as (Ca, Sr) S: Eu, Eu-activated aluminate phosphors such as YAlO ₃ : Eu, 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 oxidation such as Eu , Nitride or oxynitride phosphor, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, Mn activated halophosphate phosphor such as Eu, Mn, Ba ₃ MgSi ₂ O ₈ : Eu, Mn, (Ba, Sr, Ca, Mg) ₃ (Zn, Mg) Si ₂ O ₈ : Eu, Mn activated silicate phosphor such as Eu, Mn, 3.5MgO · 0.5MgF ₂ · GeO _2: Mn activated germanate salt phosphors such as Mn, Eu Tsukekatsusan nitride phosphor such as Eu-activated α-sialon, (Gd, Y, Lu _{La) 2 O 3: Eu,} Eu Bi, etc., Bi-activated oxide phosphor, (Gd, Y, Lu, La) 2 O 2 S: Eu, Eu Bi, etc., Bi Tsukekatsusan sulfide phosphor (Gd, Y, Lu, La) VO ₄ : Eu, Bi activated vanadate phosphors such as Eu and Bi, SrY ₂ S ₄ : Eu and Ce activated sulfide phosphors such as Eu and Ce, CaLa ₂ S ₄ : Ce-activated sulfide phosphor such as Ce, (Ba, Sr, Ca) MgP ₂ O ₇ : Eu, Mn, (Sr, Ca, Ba, Mg, Zn) ₂ P ₂ O ₇ : Eu, Eu, Mn activated phosphor phosphor such as Mn, (Y, Lu) ₂ WO ₆ : Eu, Mo activated tungstate phosphor such as Eu, Mo, (Ba, Sr, Ca) _x Si _y N _z : Eu, Ce (where x, y, z represent 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 Ce phosphors such as salt phosphors, ((Y, Lu, Gd, Tb) _1-xy Sc _x Ce _y ) ₂ (Ca, Mg) _1-r (Mg, Zn) _{2 + r} Si _zq Ge _q O _{12 + δ} 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 red phosphors, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (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 ₂ : Eu, (Ca, Sr) S: Eu , (La, Y) ₂ O ₂ S: Eu or Eu complex, preferably (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca 2, 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 or _{(La, Y) 2 O 2} S: Eu or Eu (dibenzoylmethane) ₃ · Preferably contains a β- diketone Eu complex or carboxylic acid type Eu complex such as 10-phenanthroline complex, (Ca, Sr, Ba) 2 Si 5 (N, O) 8: Eu, (Sr, Ca) AlSi (N, O): Eu or (La, Y) ₂ O ₂ S: Eu is particularly preferred.

Of the above examples, (Sr, Ba) ₃ SiO ₅ : Eu is preferable as the orange phosphor.
In addition, orange or red fluorescent substance may use only 1 type, and may use 2 or more types together by arbitrary combinations and ratios.

(Blue phosphor)
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, more preferably 460 nm or less. It is preferable that it exists in.

In addition, the half-value width of the emission peak of the blue phosphor is usually in the range of 20 nm to 80 nm.
The blue phosphor, the external quantum efficiency is usually 60% or more, preferably more than 70%, the median diameter D ₅₀ is usually 1μm or more, preferably 5μm or more, more preferably 10mμ more usually It is 30 μm or less, preferably 20 μm or less, more preferably 15 μm or less.

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-based 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): Europium activated phosphor represented by Eu, composed of a calcium halophosphate phosphor, and growth particles having a substantially cubic shape as a regular crystal growth shape, and emits light in a blue region (Ca, Sr, Ba) ₂ B ₅ Europium-activated alkaline earth chloroborate phosphor represented by O ₉ Cl: Eu, composed of fractured particles having a fractured surface, blue-green Europium activated alkaline earth aluminate-based phosphors represented by (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu that emit light in the color region. It is done.

In addition, other blue phosphors include Sn-activated phosphate phosphors such as Sr ₂ P ₂ O ₇ : Sn, (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba). ₄ Al ₁₄ O ₂₅ : Eu, 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 attached Active aluminate phosphor, Ce-activated thiogallate phosphor such as SrGa ₂ S ₄ : Ce, CaGa ₂ S ₄ : Ce, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, Mn, etc. Active aluminate phosphor, (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 Eu-activated silicate phosphor such as O ₈ : Eu, (Sr, Ba) ₃ MgSi ₂ O ₈ : Eu, Eu-activated phosphate phosphor such as Sr ₂ P ₂ O ₇ : Eu, ZnS: Ag, ZnS: sulfide phosphors such as Ag and Al, Y ₂ SiO ₅ : Ce activated silicate phosphors such as Ce, tungstate phosphors 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, Mn -activated borate phosphate phosphors such as Eu Sr ₂ Si ₃ O ₈ .2SrCl ₂ : Eu-activated halosilicate phosphor such as Eu, SrSi ₉ Al ₁₉ ON ₃₁ : Eu-activated oxynitride phosphor such as Eu, EuSi ₉ Al ₁₉ ON ₃₁ , _{la 1-x Ce x Al (} Si 6-z Al z) (N 10-z O z) ( here, x, and y are each 0 ≦ Is a number satisfying ≦ 1,0 ≦ z ≦ 6.) , La 1-xy Ce x Ca y Al (Si 6-z Al z) (N 10-z O z) ( here, x, y, and z is a number satisfying 0 ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ z ≦ 6, respectively), etc. It is also possible to use Ce-activated oxynitride phosphors and the like.

  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 or It is preferable to contain (Ba, Ca, Mg, Sr) ₂ SiO ₄ : Eu, and (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ ( Cl, F) ₂ : Eu or (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : Eu is more preferable, and BaMgAl ₁₀ O ₁₇ : Eu, Sr ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu or Ba ₃ MgSi ₂ O ₈ : Eu is more preferable. Of these, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu or (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu is particularly preferred for illumination and display applications.
In addition, only 1 type may be used for blue fluorescent substance and it may use 2 or more types together by arbitrary combinations and a ratio.

(Yellow phosphor)
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 there.

Further, the half-value width of the emission peak of the yellow phosphor is usually in the range of 60 nm to 200 nm.
The yellow phosphor has an external quantum efficiency of usually 60% or more, preferably 70% or more, and a median diameter D ₅₀ is usually 1 μm or more, preferably 5 μm or more, more preferably 10 mμ or more. It is 30 μm or less, preferably 20 μm or less, more preferably 15 μm or less.

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 Sc. And M ^a ₃ M ^b ₂ ^Mc ₃ O ₁₂ : Ce (where M ^a is a divalent metal element and M ^b is a trivalent metal element) , M ^c represents a tetravalent metal element.) A garnet-based phosphor having a garnet structure represented by AE ₂ M ^d O ₄ : Eu (where AE is Ba, Sr, Ca, Mg, and represents at least 1 kind of elements selected from the group consisting of Zn, M ^d is, Si, and / or represent Ge.) Orusoshiri Kate phosphors represented by such as oxygen constituting the phosphor of these systems Of oxynitride, AEAl, in which a part of the oxynitride is replaced with nitrogen A nitride system having a CaAlSiN ₃ structure such as Si (N, O) ₃ : Ce (where AE represents at least one element selected from the group consisting of Ba, Sr, Ca, Mg and Zn). Examples thereof include phosphors activated with Ce such as phosphors.

Other examples of yellow phosphors include 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. Body, Ca _x (Si, Al) ₁₂ (O, N) ₁₆ : phosphor activated by Eu such as oxynitride phosphor having sialon structure such as Eu, (M _1-ab 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. It is also possible to use Eu-activated or Eu / Mn co-activated halogenated borate phosphors.

Moreover, as yellow fluorescent substance, for example, brilliant sulfoflavine
FF (Color Index Number 56205), basic yellow HG (Color Index Number 46040), eosine (Color Index Number 45380), rhodamine
It is also possible to use fluorescent dyes such as 6G (Color Index Number 45160).
In addition, yellow fluorescent substance may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(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. This second phosphor is a phosphor having an emission peak 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.

As described above, when a green phosphor is used as the first phosphor, examples of the second phosphor include other than a green phosphor such as an orange to red phosphor, a blue phosphor, and a yellow phosphor. A phosphor is used. When an orange or red phosphor is used as the first phosphor, examples of the second phosphor include phosphors other than orange or red phosphors such as a green phosphor, a blue phosphor, and a yellow phosphor. Use. When a blue phosphor is used as the first phosphor, a phosphor other than a blue phosphor such as a green phosphor, an orange to red phosphor, or a yellow phosphor is used as the second phosphor. When a yellow phosphor is used as the first phosphor, a phosphor other than a yellow phosphor such as a green phosphor, an orange to red phosphor, or a blue phosphor is used as the second phosphor.
Examples of the green phosphor, orange to red phosphor, blue phosphor, and yellow phosphor include the same phosphors as described in the section of the first phosphor.

The median diameter D ₅₀ of the second phosphor used in the light emitting device of the present invention is usually 10 μm or more, preferably 12 μm or more, and usually 30 μm or less, preferably 25 μm or less. When the median diameter D ₅₀ is too small, and the luminance decreases tends to phosphor particles tend to aggregate. On the other hand, when the median diameter D ₅₀ is too large, there is a tendency for blockage, such as uneven coating or a dispenser.

(Combination of second phosphors)
As the second phosphor, only one kind of phosphor may be used, or two or more kinds of phosphors may be used in any combination and 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 and ratio of the phosphors used as the second phosphor, and the like may be arbitrarily set according to the use of the light emitting device.

  For example, the case where the phosphor of the present invention having the chemical composition represented by the formula [1] is used as the first phosphor will be described as an example. Since the phosphor having the chemical composition represented by the formula [1] is usually a green to yellow-green phosphor, the second phosphor includes an orange to red phosphor, a blue phosphor, a yellow phosphor, and the like. Used. At this time, in the light emitting device, whether or not the second phosphor is used and the type thereof may be appropriately selected according to the use of the light emitting device. For example, when the light emitting device of the present invention is configured as a green light emitting device, only the first phosphor (green 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 (green phosphor), and the first phosphor so as to obtain desired white light. What is necessary is just to combine 2 fluorescent substance 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: (I) to (iii) are included.

(I) A blue phosphor (blue LED or the like, preferably having a light emission peak in a wavelength range of 420 nm to 500 nm) is used as the first phosphor, and a green phosphor (formula [ 1) and a red phosphor (preferably one having an emission peak in the wavelength range of 570 nm to 780 nm) is used as the second phosphor. . In this case, the red phosphor is preferably one or more red phosphors selected from the group consisting of (Sr, Ca) AlSiN ₃ : Eu.

(Ii) A near-ultraviolet light emitter (near-ultraviolet LED or the like, preferably having a light emission peak in a wavelength range of 300 nm to 420 nm) is used as the first light emitter, and a green phosphor (first phosphor) is used. The phosphor of the present invention having a chemical composition represented by the formula [1] is used, and the second phosphor is preferably a blue phosphor (having an emission peak in the wavelength range of 420 nm or more and 490 nm or less) and. A red phosphor (preferably one having an emission peak in the wavelength range of 570 nm to 780 nm) is used in combination. In this case, as the blue phosphor, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu and (Mg, Ca, Sr, Ba) ₅ (PO ₄ ) ₃ (
Cl, F): One or two or more blue phosphors selected from the group consisting of Eu are preferred.
The red phosphor is preferably one or two or more red phosphors selected from the group consisting of (Sr, Ca) AlSiN ₃ : Eu and La ₂ O ₂ S: Eu. Among them, it is preferable to use a near ultraviolet LED, the phosphor of the present invention, BaMgAl ₁₀ O ₁₇ : Eu as a blue phosphor, and (Sr, Ca) AlSiN ₃ : Eu as a red phosphor.

(Iii) A blue phosphor (blue LED or the like, preferably having an emission peak in a wavelength range of 420 nm to 500 nm) is used as the first phosphor, and a green phosphor (formula [ The phosphor of the present invention having a chemical composition represented by 1] is used, and an orange phosphor is used as the second phosphor. In this case, the orange phosphor preferably has an emission peak in the wavelength range of 580 nm or more and 620 nm or less, and (Sr, Ba) ₃ SiO ₅ : Eu is particularly preferable.

Specific examples of preferable combinations of the phosphors in the case of (i) are listed in Table 3.

In the above combinations, as shown in Table 4 below, by using (Ba, Sr) ₂ SiO ₄ : Eu or Sr ₂ GaS ₄ : Eu as the green phosphor, the balance between color tone and emission intensity is particularly excellent. In addition, a light emitting device for a liquid crystal backlight source can be obtained.

  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 and the ratio of the fluorescent substance to mix.

(Sealing material)
In the light emitting device of the present invention, the first and / or second phosphors are usually used after being dispersed and sealed in a liquid medium which is a sealing material, and then cured by heat or light.
Examples of the liquid medium include [4. Examples thereof are the same as those described in the section “Fluorescent substance-containing composition”.

  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, a uniform glass layer may be formed as a metalloxane bond, and is present in a particulate form in the sealing member. You may do it. 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 silicon oxide, aluminum oxide, zirconium oxide, titanium oxide, yttrium oxide, niobium oxide, etc. with a silicone-based material, the metal element can be present in the sealing member in the form of particles. .

  The liquid medium may further contain known additives such as a diffusing agent, a filler, a viscosity modifier, and an ultraviolet absorber. In addition, only 1 type may be used for these additives, and 2 or more types may be used together by arbitrary combinations and a ratio.

[5-2. Configuration of light emitting device (others)]
The other configurations of the light emitting device of the present invention are not particularly limited as long as the first light emitting body and the second light emitting body described above are provided. Usually, the first light emitting body described above is formed on an appropriate frame. And a second light emitter. At this time, the second light emitter is excited by the light emission of the first light emitter (that is, the first and second phosphors are excited) to emit light, and the first light emitter emits light. And / or it arrange | positions so that light emission of a 2nd light-emitting body may be taken out outside. In this case, the first phosphor and the second phosphor are not necessarily mixed in the same layer. For example, the second phosphor is contained on the layer containing the first phosphor. For example, the phosphor may be contained in a separate layer for each color development of the phosphor, such as by stacking layers.

  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.

[5-3. 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. Any change can be made.

  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 is a mount lead, reference numeral 6 is an inner lead, reference numeral 7 is an excitation light source (first light emitter), reference numeral 8 is a phosphor-containing resin portion, reference numeral 9 is a conductive wire, reference numeral Reference numeral 10 denotes 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 resin portion as 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 indicate electrodes.

[5-4. 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 where ordinary light-emitting devices are used. However, since the color reproduction range is wide and the color rendering property is high, illumination is particularly important. It is particularly preferably used as a light source for a device or an image display device.

[5-4-1. 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 phosphor-containing resin part as the containing part (second light emitter) absorbs and emits visible light, while having high color rendering due to color mixing with blue light or the like that is not absorbed by the phosphor. Luminescence is obtained, and this light 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). Become.

[5-4-2. 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.

The color reproduction range by light after passing through the color filter at this time is usually 60% or more, preferably 80% or more, more preferably 90% or more, more preferably 100% or more, and usually 150% in terms of NTSC ratio. It is as follows.
The amount of light transmitted from each color filter (light utilization efficiency) relative to the amount of light transmitted from the entire color filter is usually 20% or more, preferably 25% or more, more preferably 28% or more, Preferably it is 30% or more. The higher the utilization efficiency, the better, but it is usually 33% or less because of the use of three filters of red, green and blue.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples. However, the present invention is not limited to the following examples without departing from the gist thereof.

[Evaluation methods]
The physical property values of the phosphors obtained in Examples and Comparative Examples described later were evaluated by the following methods.

[Luminescent characteristics]
・ Emission spectrum
In Examples 1-1 to 1-7, Comparative Example 1-1, and Examples 3-1 to 3-2, emission spectra were measured using FP-6500 manufactured by JASCO Corporation. The excitation wavelength was 455 nm.
Further, in Examples 2-1 to 2-5 and Comparative Example 2-1, the emission spectrum was measured at room temperature (25 ° C.) using a 150 W xenon lamp as an excitation light source and a multichannel CCD detector C7041 (spectrum measurement device). Measured using a fluorescence measuring apparatus (manufactured by JASCO Corporation) equipped with Hamamatsu Photonics). More specifically, 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 emitted 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 480 nm to 800 nm, and a personal computer is used. An emission spectrum was obtained through signal processing such as sensitivity correction. In the measurement, the slit width of the light-receiving side spectroscope was set to 1 nm.

・ Relative brightness
The relative luminance is calculated from the stimulation value Y in the XYZ color system calculated according to JIS Z8701 based on the data in the wavelength region of 480 nm to 800 nm (in the case of the excitation wavelength of 455 nm) of the emission spectrum. It was calculated as a relative value (hereinafter sometimes simply referred to as “luminance”) with the stimulation value Y of the yellow phosphor YAG (product number: P46-Y3) made as 100%.

・ Chromaticity coordinates
The chromaticity coordinates of the x, y color system (CIE 1931 color system) are the chromaticity coordinates in the XYZ color system defined in JIS Z8701- from the data of the wavelength region excluding the excitation wavelength region of the emission spectrum. Calculated as CIEx and CIEy.

[Shape of phosphor particles]
・ Circularity
Before measuring the circularity, the phosphor sample was dispersed with ultrasonic waves for 90 seconds using an ultrasonic dispersing device (manufactured by Kaijo Co., Ltd.) with a frequency of 19 KHz and an ultrasonic intensity of 25 W.
The circularity was measured using a flow type particle image analyzer (“FPIA-2000” manufactured by Sysmex), and the proportion of particles having a circularity of less than 85% was calculated.

[Particle size]
・ Median diameter D ₅₀
Using a laser diffraction / scattering type particle size distribution measuring apparatus model 1064 made by CILAS, measurement was performed using water as a dispersion medium to obtain a weight-based particle size distribution curve.
In the weight particle size distribution curve, the accumulated value was calculated particle size value when the 50% as the median diameter D _50.

・ Weight diameter D ₁₀ , weight diameter D ₉₀ , and weight diameter D _MAX
In the weight-based particle size distribution curve obtained by the measurement of the median diameter D _50, the integrated value is the weight diameter D ₁₀ of the particle size value when the 10%, by weight diameter D of the particle size value when the integrated value of 90% ₉₀ , the particle diameter value when the integrated value was 100% was calculated as the weight diameter D _MAX .

・ QD (4-minute deviation)
QD is a particle size distribution value (D ₂₅ ) when the integrated value is 25% and a particle size value (D ₇₅ ) when the integrated value is 75% in the weight-based particle size distribution curve obtained by measuring the median diameter D _50. Was calculated as a value represented by (D ₇₅ -D ₂₅ ) / (D ₇₅ + D ₂₅ ).

・ Scanning electron microscope (SEM) photograph
In each Example and Comparative Example, in order to observe the shape and the like of the phosphor particles, SEM photographs were obtained at 1000 times and 3000 times using SEM (manufactured by Hitachi, S-4500 and JEOL, JSM-6300F). I took a picture.

[Composition analysis]
・ Cl content
A sample is prepared by a combustion absorption method using a combustion absorption device (Dia Instruments, AQF-100 type), and then Ion Chromatography (IC) measurement is performed using an IC analyzer (Dionex, DX-500). Thus, the amount of Cl contained in the sample was measured.

・ Cs amount
After preparing a sample by performing microwave wet decomposition using a microwave wet decomposition apparatus (CEM, MARS5 type), using an ICP mass spectrometer (Agilent Technologies, 7500ce type), Inductively Coupled Plasma Mass The amount of Cs was measured by performing Spectrometry (ICP-MS) measurement.

[Example 1-1]
・ Mixing process
As phosphor raw materials, powders of barium carbonate (BaCO ₃ ), strontium carbonate (SrCO ₃ ), europium oxide (Eu ₂ O ₃ ), and silicon dioxide (SiO ₂ ) were used. These phosphor materials were weighed so that the charged composition was as shown in Table 5 below. These phosphor raw material powders were mixed with a small desktop mixer until dry and sufficiently uniform to obtain a raw material mixture.

・ Baking process
(Primary firing)
The obtained raw material mixture was filled in an alumina crucible and set in a box-type electric furnace (manufactured by Motoyama, RH-2035D).
The temperature was raised to 1050 ° C. (maximum temperature reached) at a rate of temperature rise of 5 ° C./min in a nitrogen atmosphere at atmospheric pressure, and held for 5 hours to obtain a baked cake as a baked product. Next, after cooling to room temperature, the contents of the crucible were taken out and crushed.

(Secondary firing)
SrCl ₂ was added to the fired product obtained by primary firing so that the amount of SrCl ₂ with respect to the total amount (hereinafter sometimes referred to as “primary fired product”) was 2% by weight (Table 5). reference)
After addition and mixing, the mixture was filled in an alumina crucible, and solid graphite was placed thereon and covered. The crucible was set in an electric furnace (HAF 443060 manufactured by Hirokisha).

  After reducing the pressure to 5 Pa with a vacuum pump in an electric furnace, hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)) was introduced until atmospheric pressure was reached. Thereafter, while flowing hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)) at a rate of 2.5 ± 0.5 L / min, 1225 ° C. (maximum) at a heating rate of 5 ° C./min under atmospheric pressure. The temperature was raised to a final temperature) and held for 5 hours. Subsequently, after cooling to room temperature, the obtained fired product was taken out.

・ Softening process
The fired product (320 g) obtained in the firing step was put in a magnetic container (inner diameter 120 mm). At this time, the thickness of the fired product in the magnetic container was 5 cm ± 2 cm. At this time, pressure filling was not performed. This magnetic container was placed in an autoclave (Hiclave HG-50, manufactured by Hirayama Seisakusho), and the obtained fired product was left in the autoclave, that is, under saturated steam for 2 hours under conditions of 135 ° C. and 0.33 MPa.
In addition, said pressure value adds the normal pressure 0.1MPa to the pressure (differential pressure with respect to a normal pressure) displayed on an apparatus. The same applies to the following embodiments.

・ Post-processing process
The softened fired product obtained in the softening step was pulverized for 6 hours by a ball mill. The coarse particles were passed through a sieve while the pulverized product was in a slurry state, and then washed with water. After drying, the phosphor was manufactured by sieving to break up the agglomerated particles.

[Example 1-2]
In the firing step, SrCl ₂ and CsCl were added and mixed such that the amounts of SrCl ₂ and CsCl were 3% by weight and 1% by weight, respectively, and the time of secondary firing was set to 8 hours, and A phosphor was produced under the same conditions as in Example 1-1 except that the grinding time in the ball mill was set to 1 hour in the post-treatment process.

[Example 1-3]
In the firing step, the temperature of the primary firing was set to 1100 ° C., and in addition to the primary firing and the secondary firing, firing after the primary firing and before the secondary firing was performed at a maximum reached temperature of 1250 ° C. and a holding time of 8 hours (1. A phosphor was produced under the same conditions as in Example 1-2 except that the fifth firing was performed and the standing time was 5 hours in the softening step.

[Example 1-4]
In the softening step, 110 g of the fired product obtained in the firing step was placed in a magnetic container (inner diameter 120 mm) and left for 95 hours in an atmosphere of 85 ° C. and 85% humidity, and using a magnetic mortar in the post-treatment step. A phosphor was produced under the same conditions as in Example 1-2 except that the pulverization was performed.

[Example 1-5]
In the softening step, 110 g of the fired product obtained in the firing step was placed in a magnetic container (inner diameter 120 mm) and left in an atmosphere of a temperature of 25 ° C. and a humidity of 50% for 192 hours, and using a magnetic mortar in the post-treatment step A phosphor was produced under the same conditions as in Example 1-2 except that the pulverization was performed.

[Example 1-6]
The fired product obtained by the primary firing was mixed and added so that the amounts of SrCl ₂ and CsCl were 3.5% by weight and 2% by weight, respectively, with respect to the total amount of the fired product, and the softening process was allowed to stand. A phosphor was produced under the same conditions as in Example 1-2 except that the time was 5 hours.

[Example 1-7]
The phosphor material was weighed so that the charged composition was the same as in Example 1-4, and a phosphor was produced under the same conditions as in Example 1-2 using the phosphor material.

[Comparative Example 1-1]
The phosphor was obtained under the same conditions as in Example 1-1, except that the fired product (320 g) obtained in the firing step was not subjected to the softening step and was ground using a magnetic mortar instead of the ball mill. Manufactured.

[Example 2-1]
・ Mixing process
As phosphor materials, powders of barium carbonate (BaCO ₃ ), strontium carbonate (SrCO ₃ ), calcium carbonate (CaCO ₃ ), europium oxide (Eu ₂ O ₃ ), and silicon dioxide (SiO ₂ ) were used. These phosphor materials were weighed out so that the charged composition was as shown in Table 5. These phosphor raw material powders were mixed with a small desktop mixer until dry and sufficiently uniform.

・ Baking process
(Primary firing)
The obtained raw material mixture was filled in an alumina crucible and set in a box-type electric furnace (manufactured by Motoyama, RH-2035D).
In a nitrogen atmosphere, under atmospheric pressure, the temperature was raised to 1100 ° C. (maximum temperature reached) at a rate of temperature increase of 5 ° C./min and held for 12 hours to obtain a fired product. Next, after cooling to room temperature, the contents of the crucible were taken out and crushed.

(Secondary firing)
SrCl ₂ was added to the calcined product and mixed so that the amount of SrCl ₂ was 2 wt% with respect to the total amount of the primary calcined product, then filled in an alumina crucible, solid graphite was placed on it, and the lid was covered. did. The crucible was set in an electric furnace (HAF 443060 manufactured by Hirokisha).

  After reducing the pressure to 5 Pa with a vacuum pump in an electric furnace, hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)) was introduced until atmospheric pressure was reached. Then, while flowing hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)) at a rate of 0.5 ± 0.5 L / min, 1200 ° C. (maximum at a heating rate of 5 ° C./min under atmospheric pressure) The temperature was raised to (attainable temperature) and held for 6 hours. Subsequently, after cooling to room temperature, the obtained fired product was taken out.

・ Softening process
The fired product (10 g) obtained in the above firing step was placed in an alumina container (inner diameter: 80 mm). At this time, pressure filling was not performed. This magnetic container is placed in an autoclave (Hiclave HG-50, manufactured by Hirayama Seisakusho), and the obtained fired product is left in the autoclave, that is, under saturated steam, at 130 ° C. and 0.33 MPa for 1.5 hours. did.

・ Post-processing process
The softened fired product obtained in the softening step was pulverized using an alumina mortar. The coarse particles were passed through a sieve while the pulverized product was in a slurry state, and then washed with water. After drying, the phosphor was manufactured by sieving to break up the agglomerated particles.

[Example 2-2]
In the mixing step, phosphors were produced under the same conditions as in Example 2-1, except that each raw material powder was weighed so that the charged composition had the composition shown in Table 5.

[Examples 2-3 to 2-5]
In the mixing step, each of the raw material powders was weighed so that the charged composition became the composition shown in Table 5, and the phosphor was subjected to wet mixing in the mixing step under the same conditions as in Example 2-1. Manufactured.
Note that terbium oxide (Tb ₄ O ₇ ) was used as the Tb source, and cerium oxide (CeO ₂ ) was used as the Ce source.

[Comparative Example 2-1]
A phosphor was produced under the same conditions as in Example 2-3, except that the softening step was not performed on the fired product obtained in the firing step.

[Evaluation]
The phosphors produced in the examples and comparative examples were evaluated by the evaluation method described above. The results are shown in Table 6.
Moreover, about Example 1-1, 1-2, 1-3, and Comparative Example 1-1, the SEM photograph was image | photographed by the method mentioned above. Drawing substitute photographs showing the results are shown in FIGS. 4, 5, 6 and 7, respectively. 4 to 7, (a) shows a photograph taken at a magnification of 1000 times, and (b) shows a photograph taken at a magnification of 3000 times.

  Moreover, when the quantity of Cl and Cs was analyzed by the method mentioned above about the fluorescent substance obtained in Example 1-6, Cl was contained at 21 ppm and Cs was contained at 19 ppm. Furthermore, when the quantity of Cl was analyzed by the method mentioned above about the fluorescent substance obtained in Example 1-7, 36 ppm of Cl was contained.

[Consideration]
From the above results, the following can be understood.
When Examples 1-1 to 1-7 are compared with Comparative Example 1-1, it is understood that the light emission characteristics such as luminance and the particle size characteristics such as circularity are clearly improved by providing the softening step. . This is considered to be because the damage to the phosphor due to pulverization in the post-processing step can be reduced by providing the softening step. Specifically, by providing a softening step, it is possible to suppress the generation of fine particles during pulverization, to reduce the value of the 4-minute deviation of the particle size distribution, and to break the phosphor particles during pulverization. It is considered that the ratio of particles having low circularity can be reduced and the ratio of particles having low circularity can be reduced. In terms of manufacturing, if a softening step is provided, it is not necessary to use a large pulverizer to pulverize a hard fired product, which is advantageous in terms of cost.

In addition, also from the SEM photograph shown to FIGS. 4-7, the fluorescent substance of the Example which provided the softening process rather than the fluorescent substance of a comparative example has each fluorescent substance particle uniform, and is nearly spherical. It can be seen that it has a particle shape. In particular, in Example 1-3 in which the primary firing was performed, the surface state of the particles was improved by applying sufficient heat treatment by firing. These effects on the shape of the phosphor particles are considered to contribute greatly to the improvement of luminance.
Moreover, it was confirmed that the phosphor obtained in Examples 1-6 and 1-7 contains Cl or Cs. Cl and Cs are considered to be derived from flux, and the phosphors obtained in other examples are also considered to contain elements derived from flux.
In Examples 2-1 to 2-5, compared with Examples 1-1 to 1-7, the amount of the fired product to be subjected to the softening process is small. Comparing Comparative Example 2-1 with Examples 2-1 to 2-5, when the softening step is performed, the proportion of particles having a circularity of less than 85% is obtained even when the production scale is small. It can be seen that the effect of decreasing the relative luminance is obtained.
Moreover, when Examples 1-1 to 1-7 are compared with Comparative Example 1-1, the proportion of particles having a circularity of less than 85% is reduced and the relative luminance is improved by performing the softening step. In addition to the effect, it can be seen that the effect that the 4-minute deviation in particle size (“QD” in Table 6) is 0.4 or less is obtained.
Therefore, the production method having the softening step of the present invention can provide particularly excellent effects when used for industrial production with a large scale.
[Comparative Example 3-1]
・ Mixing process
As phosphor materials, calcium carbonate (CaCO _3), magnesium carbonate (MgCO _3), scandium oxide _(Sc 2 _CO 3), cerium oxide _(CeO 2), using each powder of silicon dioxide (SiO _2). These phosphor materials were weighed so that the charged composition was Ca _2.94 Ce _0.06 Sc _1.93 Mg _0.07 Si ₃ O ₁₂ . These phosphor raw material powders were mixed with a small desktop mixer until dry and sufficiently uniform to obtain a raw material mixture.

・ Baking process
(Primary firing)
The obtained raw material mixture was filled in an alumina crucible and set in a box-type electric furnace (manufactured by Motoyama, RH-2035D).
In a nitrogen atmosphere, under atmospheric pressure, the temperature was raised to 1380 ° C. (maximum temperature reached) at a rate of temperature increase of 5 ° C./min and held for 5 hours to obtain a baked cake as a baked product. Next, after cooling to room temperature, the contents of the crucible were taken out and crushed.

(Secondary firing)
The obtained fired product was mixed and mixed so that the amount of CaCl ₂ · 2H ₂ O was 13% by weight relative to the total amount of the primary fired product, and then filled in an alumina crucible and capped. The crucible was set in an electric furnace (HAF 443060 manufactured by Hirokisha).

  After reducing the pressure to 5 Pa with a vacuum pump in an electric furnace, hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)) was introduced until atmospheric pressure was reached. Then, while flowing hydrogen-containing nitrogen gas (nitrogen: hydrogen = 96: 4 (volume ratio)) at a rate of 2.5 ± 0.5 L / min, 1450 ° C. (maximum) at a heating rate of 5 ° C./min under atmospheric pressure. The temperature was raised to (attainable temperature) and held for 6 hours. Subsequently, after cooling to room temperature, the obtained fired product was taken out.

・ Post-processing process
We tried crushing the calcined product (400 g) obtained without the softening process with a magnetic mortar and pestle, but it was difficult to grind because the calcined product was very hard, producing a phosphor. I couldn't.

[Example 3-1]
A phosphor was produced in the same manner as Comparative Example 3-1, except that the following softening step and post-treatment step were carried out after the secondary firing to produce the phosphor.

・ Softening process
The fired product (400 g) obtained in the above firing step was placed in a magnetic container (inner diameter 120 mm). At this time, the thickness of the fired product in the magnetic container was 7 cm ± 2 cm. At this time, pressure filling was not performed. This magnetic container was placed in an autoclave (Hiclave HG-50, manufactured by Hirayama Seisakusho), and the obtained fired product was left in the autoclave, that is, under saturated steam for 2 hours under conditions of 135 ° C. and 0.33 MPa.

・ Post-processing process
The softened baked product obtained in the softening step was pulverized manually with a magnetic mortar and pestle and then pulverized with a ball mill for 12 hours. The coarse particles were passed through a sieve while the pulverized product was in a slurry state, and then washed with water. After drying, the phosphor was manufactured by sieving to break up the agglomerated particles.

[Example 3-2]
A phosphor was produced under the same conditions as in Example 3-1, except that it was pulverized using a grinder mill before the post-treatment process.
When grinding using a grinder mill, the disc gap was 50 μm, and the rotational family was 1200 rpm.
[Evaluation]
The phosphors produced in the examples and comparative examples were evaluated by the evaluation method described above. The results are shown in Table 7.
In Table 7, “post-treatment yield (%)” is a value calculated from the following formula [A]. In the following formula [A], “weight (g) before being used in the post-treatment process” refers to the weight of the softened fired product obtained in the softening process to be used in the post-treatment process.
Post-treatment yield (%) =
{(Weight of phosphor after post-treatment step (g)) / Weight before subjecting to post-treatment step (g)} × 100
... Formula [A]
[Consideration]
From the above results, the following can be understood.
As shown in Examples 3-1 and 3-2, if a softening step is provided, even after the baking step, even if the baked cake is a phosphor that is too hard to be crushed by human power, light is emitted on a large scale. It is possible to produce a phosphor that can withstand both practical characteristics and particle size characteristics.
Furthermore, as shown in Example 3-2, if the grinding is performed using a grinder mill, the ratio of the number of particles having a circularity of 85% or more (number%) slightly increases, but the light emission characteristics and particle size characteristics The working time can be greatly shortened without sacrificing, and the post-treatment yield (%) is also improved. This shortening of the working time and improvement of the post-treatment yield (%) greatly contribute to the improvement of productivity.

The phosphor of the present invention can be used in any industrial field, for example, in a light emitting device. Among these, the phosphor of the present invention is suitable for use in a white light emitting device.
The phosphor, the phosphor-containing composition and the light emitting device of the present invention are widely used and can be used in the fields of illumination and display. Among them, the LED for general illumination is particularly suitable for the purpose of realizing a high-power lamp, particularly a white LED for backlight having a high luminance and a wide color reproduction range.

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 cross sections showing an embodiment of a light emitting device having an excitation light source (first light emitter) and a phosphor-containing portion (second light emitter). FIG. It is sectional drawing which shows typically one Embodiment of the illuminating device of this invention. (A) and (b) are drawings substitute photographs showing SEM photographs of the phosphors obtained in Example 1-1 of the present invention, (a) shows photographs taken at a magnification of 1000 times, (B) shows an image taken at a magnification of 3000 times. (A) and (b) are drawings substitute photographs showing SEM photographs of the phosphors obtained in Example 1-2 of the present invention, (a) shows those photographed at a magnification of 1000 times, (B) shows an image taken at a magnification of 3000 times. (A) and (b) are drawings substitute photographs showing SEM photographs of the phosphors obtained in Example 1-3 of the present invention, (a) shows those photographed at a magnification of 1000 times, (B) shows an image taken at a magnification of 3000 times. (A) And (b) is drawing substitute photograph which shows the SEM photograph which image | photographed the fluorescent substance obtained in Comparative Example 1-1, (a) shows what was image | photographed by 1000 time magnification, (b) Indicates an image taken at a magnification of 3000 times.

Explanation of symbols

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

Claims (18)

A phosphor having an alkaline earth metal element as a part of a base crystal and having an orthosilicate or garnet crystal structure,
The proportion of particles having a circularity of phosphor particles of less than 85% is 4% by number or less, and the value of the 4-minute deviation of the particle size of the phosphor particles is 0.4 or less, Phosphor. 2. The phosphor according to claim 1, comprising 1 ppm or more of an element derived from a water-soluble flux. It is represented by a composition formula selected from the group consisting of (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu and Ca ₃ (Sc, Mg, Na, Li) ₂ Si ₃ O ₁₂ : Ce. The phosphor according to claim 1 or 2. The phosphor according to claim 1 or 2, which has a chemical composition represented by the following formula [1].
(M ^I _(1-xy) M ^II _x M ^III _y ) _α SiO _β [1]
(In the above formula [1],
M ^I represents one or more elements selected from the group consisting of Ba, Ca, Sr, Zn and Mg,
M ^II represents one or more activator elements capable of taking a divalent and trivalent valence,
M ^III represents one or more elements selected from the group consisting of Tb, Pr, Ce, Lu, La, and Gd,
x, y, α and β are respectively
0.01 <x <0.3,
0 ≦ y ≦ 0.025,
1.5 ≦ α ≦ 2.5, and
It represents a number satisfying 3.5 ≦ β ≦ 4.5. ) In the formula [1], M ^I contains at least Ca, and the molar ratio of Ca when the sum of M ^I and M ^II is 2 is 0.000001 or more and 0.005 or less. The phosphor according to claim 4. In Formula [1], M ^I contains at least Ba and Sr,
When the molar ratios of Ba and Sr to the entire M ^I are [Ba] and [Sr], respectively, [Ba] and [Sr]
0.4 <{[Ba] / ([Ba] + [Sr])} ≦ 1
The phosphor according to claim 4 or 5, characterized in that: A method for producing a phosphor, comprising: a firing step of firing a phosphor material; and a softening step of softening a fired product obtained by the firing step. The method for producing a phosphor according to claim 7, wherein in the firing step, the phosphor material is fired in the presence of a flux. The fluorescence according to claim 7 or 8, wherein, in the softening step, the fired product is left for 0.5 hours or more in an environment where the pressure is normal pressure or higher and steam exists. Body manufacturing method. Before the firing step,
10. The method for producing a phosphor according to claim 8, further comprising a step of firing at a temperature higher than that of the firing step. The phosphor production according to any one of claims 7 to 10, further comprising a pulverization step of pulverizing the fired product using a pulverizer having a mortar structure after the softening step. Method. A phosphor-containing composition comprising the phosphor according to any one of claims 1 to 6 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, wherein the second light emitter is any one of claims 1 to 6. A light emitting device comprising one or more of the phosphors described in 1) as a first phosphor. The light emitting device according to claim 13, wherein the second phosphor includes at least one phosphor having a different emission peak wavelength from the first phosphor as the second phosphor. . The first light emitter has a light emission peak in a wavelength range of 420 nm to 500 nm, and the second light emitter has a light emission peak in a wavelength range of 570 nm to 780 nm as the second phosphor. The light emitting device according to claim 14, comprising at least one phosphor. The first light emitter has a light emission peak in a wavelength range of 300 nm to 420 nm, and the second light emitter has a light emission peak in a wavelength range of 420 nm to 490 nm as the second phosphor. The light emitting device according to claim 14, comprising at least one kind of phosphor and at least one kind of phosphor having an emission peak in a wavelength range of 570 nm to 780 nm. The light emitting device according to claim 13.
An image display device characterized by that. The light emitting device according to claim 13.
A lighting device.