JP2013177511A - Method for producing phosphor and phosphor obtained by the method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method for producing a phosphor, in which productivity and safety are made higher.SOLUTION: A method for producing a phosphor comprises a step for firing a raw material of the phosphor under a nitrogen-containing atmosphere. A charge composition of the raw material of the phosphor is shown by formula [1]: (A, Z)DENO. A compound containing two or more elements other than nitrogen and oxygen among elements of the formula [1] is used to be fired at ≤1,500°C.

Description

  The present invention relates to a method for producing an oxynitride phosphor, a phosphor obtained by the production method, a light emitting device using the phosphor, and the like.

  The phosphor is used in a fluorescent display tube (VFD), a field emission display (FED), a plasma display panel (PDP), a cold cathode tube (CRT), a light emitting device (LED), and the like. In any of these applications, in order to cause the phosphor to emit light, it is necessary to supply energy for exciting the phosphor to the phosphor. The phosphor is excited by an excitation source having high energy such as vacuum ultraviolet rays, ultraviolet rays, electron beams, blue light, and emits visible light.

In recent years, there has been a demand for a light emitting device that emits white light with high color rendering and color reproducibility. To achieve this, conventional silicate phosphors, phosphate phosphors, aluminate phosphors, sulfides are required. In addition to phosphors such as nitride phosphors, nitride and oxynitride phosphors are also being searched for.
For example, phosphors having a composition represented by Sr ₂ Al ₃ Si ₇ ON ₁₃ : Eu have been reported as one of oxynitrides that have attracted attention (Patent Documents 1 to 3).

In Patent Document 1, by using AlN as a starting _{material, Sr 2 Al 3 Si 7 ON} 13: manufactures Eu phosphor.
In Patent Document 2, by using AlN as a starting material under normal pressure nitrogen stream containing 10 vol% to 50 vol% of hydrogen, by firing at _{1400 ℃, Sr 2 Al 3 Si} 7 ON 13: Eu fluorescent The body is manufactured.

In Patent Document 3, the SrAlSi ₄ N ₇ : Eu phosphor is manufactured using metal Sr or metal Eu as a raw material.
On the other hand, Patent Document 4 discloses a method of manufacturing, for example, a (Sr, Ca) AlSiN ₃ : Eu phosphor using a phosphor raw material alloy.

JP 2010-106127 A JP 2011-195688 A JP 2010-518194 gazette JP 2008-013627 A

Here, in the phosphor manufacturing method described in Patent Document 1, since AlN is used as a raw material, the raw material has low reactivity and needs to be fired at high temperature and high pressure (for example, 0.72 MPa, 1850 ° C.). There is.
Moreover, in the manufacturing method of the fluorescent substance described in Patent Document 2, firing is performed in a high-concentration hydrogen-containing atmosphere exceeding the lower limit of explosion, and improvement is necessary in terms of safety.

In addition, the phosphor manufacturing method described in Patent Document 3 uses an alkaline earth metal element that is unstable in the atmosphere and a rare earth element as a raw material, which improves the safety of the raw material. is necessary.
As described above, the production methods described in Patent Documents 1 to 3 have a problem in terms of the reactivity of the raw materials or the safety of the raw materials, and there is a reactivity in putting the phosphors described in Patent Documents 1 to 3 into practical use. There is a demand for high and safe raw material compounds.

In Patent Documents 1 to 3, there is no description or suggestion that an alloy is used as a raw material. In Patent Document 4, a material suitable for manufacturing the phosphor described in Patent Documents 1 to 3 is disclosed. Not.
An object of the present invention is to find a raw material compound suitable for producing the phosphors described in Patent Documents 1 to 3, in particular, a highly reactive and safe raw material compound. An object of the present invention is to provide a production method capable of producing a phosphor with high productivity and safety.

  As a result of various studies to achieve the above-mentioned problems, the present inventors have used a compound containing two or more elements other than nitrogen and oxygen among the elements constituting the phosphor as a raw material. It is found that it is possible to synthesize phosphors, and is suitable for the production of phosphors containing oxygen among the phosphors described in Patent Documents 1 to 3, and specifically, the composition of raw materials charged It has been found that a phosphor can be particularly suitably produced when it is represented by the following formula [1]. The present invention has been accomplished based on these findings.

That is, the gist of the present invention resides in the following [1] to [8].
[1] A method for producing a phosphor having a step of firing a phosphor material in a nitrogen-containing atmosphere, wherein the charged composition of the phosphor material is represented by the following formula [1], and the following formula [1] Among the elements constituting the phosphor, firing using a compound containing two or more elements other than nitrogen and oxygen at a temperature of 1500 ° C. or less.
The following formula [1]:
^{_{(A l 1-xl, Z}} l xl) al D l bl E l cl N l dl O l el [1]
(In the formula [1], A ¹ represents an alkaline earth metal element in which Sr is essential, Z ^l represents one or more activator elements in which Eu or Ce is essential, and D ^l is essential to Si. a tetravalent metal element and, ^{E l} represents a trivalent metal element essentially containing Al, xl is a number satisfying 0.0001 ≦ xl ≦ 0.20, al, bl, cl, dl And el are respectively
0.7 ≦ al ≦ 1.3
2.5 ≦ bl ≦ 4.0
1.0 ≦ cl ≦ 3.0
3.5 ≦ (bl + cl) /al≦6.0
0.1 ≦ dl ≦ 7.0
0 <el ≦ 2.0
Indicates the number that satisfies )
[2] The phosphor according to [1], wherein a compound containing at least two alkaline earth metal elements and Al is used as the compound containing two or more elements constituting the formula [1]. Manufacturing method.
[3] A phosphor obtained by the production method according to [1] or [2]. [4] The phosphor according to [3], comprising a crystal phase having a composition represented by the following formula [2].
Following formula [2]:
(A _1-x , Z _x ) _a D _b E _c N _d O _e [2]
(In the formula [2], A represents an alkaline earth metal element essential for Sr, Z represents one or more activator elements essential for Eu or Ce, and D represents Si for essential 4 E represents a trivalent metal element in which Al is essential, x represents a number satisfying 0.0001 ≦ x ≦ 0.20, and a, b, c, d, and e are Each,
0.7 ≦ a ≦ 1.3
2.5 ≦ b ≦ 4.0
1.0 ≦ c ≦ 3.0
3.5 ≦ (b + c) /a≦6.0
5.0 ≦ d ≦ 7.0
0 <e ≦ 2.0
6.5 ≦ (d + e) /a≦7.5
Indicates the number that satisfies )
[5] A phosphor-containing composition obtained by dispersing at least one phosphor according to [3] or [4] in a liquid medium.
[6] A light-emitting device having a first light emitter (excitation light source) and a second light emitter capable of emitting visible light by converting light from the first light emitter, The second illuminant contains at least one of the phosphors described in [3] or [4] as the first phosphor, or the fluorescence described in [5] as the second illuminant. A light emitting device comprising a body-containing composition.
[7] The second light emitter contains at least one kind of phosphor having a light emission peak wavelength different from that of the first phosphor as the second phosphor. Light emitting device. [8] An illumination device or an image display device comprising the light-emitting device according to [6] or [7].

ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the fluorescent substance excellent in safety | security and productivity can be provided.
In addition, according to the present invention, it is possible to produce a high-quality phosphor. When the phosphor of the present invention is combined with an LED or the like, a light-emitting device having excellent light-emitting characteristics can be provided.

It is a perspective view which shows typically one Embodiment of the light-emitting device of this invention. It is sectional drawing which shows typically another embodiment of the light-emitting device of this invention. 2A shows a bullet-type light emitting device, and FIG. 2B shows a surface-mounted light-emitting device. It is sectional drawing which shows typically the one aspect | mode of the illuminating device of this invention.

Hereinafter, embodiments of the present invention will be described in detail. However, the present invention is not limited to the following embodiments, and various modifications can be made within the scope of the gist of the present invention. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value. Further, in the phosphor composition formula in this specification, each composition formula is delimited by a punctuation mark (,). In addition, when a plurality of elements are listed separated by commas (,), one or two or more of the listed elements may be included in any combination and composition. For example, the composition formula “(Ca, Sr, Ba) Al ₂ O ₄ : Eu” has “CaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “BaAl ₂ O ₄ : Eu”. “Ca _1−x Sr _x Al ₂ O ₄ : Eu”, “Sr _1−x Ba _x Al ₂ O ₄ : Eu”, “Ca _1−x Ba _x Al ₂ O ₄ : Eu”, _{"Ca 1-x-y Sr x} Ba y Al 2 O 4: Eu " (. in the formula, 0 <x <1,0 <y <1,0 < a x + y <1) all the comprehensive It shall be shown in

[1. Method for producing phosphor]
The phosphor production method of the present invention is a phosphor production method including a step of firing a phosphor material in a nitrogen-containing atmosphere, and a charged composition of the phosphor material is represented by the following formula [1], And it burns at the temperature of 1500 degrees C or less using the compound which contains 2 or more types of elements other than nitrogen and oxygen among the elements which comprise following formula [1].
The following formula [1]:
^{_{(A l 1-xl, Z}} l xl) al D l bl E l cl N l dl O l el [1]
(In the formula [1], A ¹ represents an alkaline earth metal element in which Sr is essential, Z ^l represents one or more activator elements in which Eu or Ce is essential, and D ^l is essential to Si. a tetravalent metal element and, ^{E l} represents a trivalent metal element essentially containing Al, xl is a number satisfying 0.0001 ≦ xl ≦ 0.20, al, bl, cl, dl And el are respectively
0.7 ≦ al ≦ 1.3
2.5 ≦ bl ≦ 4.0
1.0 ≦ cl ≦ 3.0
3.5 ≦ (bl + cl) /al≦6.0
0.1 ≦ dl ≦ 7.0
0 <el ≦ 2.0
Indicates the number that satisfies )
[Phosphor material]
The phosphor production method of the present invention (hereinafter sometimes referred to as “the production method of the present invention”) includes, as its raw material, “other than nitrogen and oxygen among elements constituting the formula [1] described later”. It is essential to use at least one kind of “compound containing two or more of these elements” (hereinafter sometimes referred to as “the raw material compound of the present invention”).

Here, the “compound” is synonymous with the definition of a compound in the Iwanami Physics and Chemical Dictionary “a pure substance that can be divided into two or more elements by chemical change”.
In the production method of the present invention, other raw materials can be used as a raw material together with the raw material compound of the present invention. Hereinafter, the raw material compound of the present invention and other raw materials (hereinafter sometimes referred to as “other raw materials”) that can be used together with the raw material compound of the present invention will be specifically described.

(Raw compound of the present invention)
The raw material compound of the present invention is a compound containing two or more elements other than nitrogen and oxygen among the elements constituting the formula [1]. More specifically, among the elements constituting the above formula [1], A ^l element, Eu elements thereof may comprise two or more elements selected from the group consisting of D ^l elements, and E ^l elements , a ^l element, Eu element may contain the D ^l element, and nitrogen or oxygen in addition to these elements if the contain two or more elements selected from the group consisting of E ^l elements. The raw material compound of the present invention may be partially nitrided or partially oxidized.

Examples of the raw material compound of the present invention include solid solutions of two or more elements, eutectic crystals, intermetallic compounds, alloys, and mixtures thereof. Among them, essential and earth alkali metal elements Sr by (hereinafter sometimes referred to as "A ^l element" or "A ^l".) And Al are thoroughly mixed in Å order, A ^l _A solid solution, an intermetallic compound, and an alloy are particularly preferable in terms of suppressing the by-production of ₂ Si ₅ N ₈ phase.

Since the alkaline earth metal is a pyrophoric substance and a water-inhibiting substance, it must be handled in an inert gas. In addition, since AlN has low reactivity, heating at a high temperature for a long time is required. As described above, from the viewpoint of safety in production and energy saving, the raw material compound of the present invention is preferably a compound containing Al and an alkaline earth metal element essential for Sr. Specific examples include SrAlSi, SrAl, Sr ₈ Al ₇ , SrAl ₂ , SrAl _{4 and the} like.

An alloy such as Sr ₈ Al ₇ and SrAl ₂ is separated into a liquid phase and a solid phase having a composition different from the alloy composition prior to melting, that is, with a peritectic reaction, as the temperature rises. When it is produced by solidification, it tends to be difficult to be an alloy solid with a uniform composition, but it can be used as a raw material compound of the present invention. When an alloy with a peritectic reaction as described above is used as a raw material compound of the present invention, it means a peritectic temperature (a temperature at which a peritectic reaction occurs) before use as a raw material (before the firing step). For example, in the case of Sr ₈ Al ₇ , the temperature is 664 ° C.) It is preferable to perform homogenization by heat treatment below.

In addition, in a method for producing a phosphor containing an alkaline earth metal element, Al, and Si, in the conventional solid phase method, there is a situation in which alkaline earth metal ions are locally surrounded by a large number of Si ions in the firing step. Appear. Once A ^ll ₂ Si ₅ N ₈ (A ^ll represents an alkaline earth metal element) is locally generated, the change to A ^ll AlSi ₄ N ₇ is an endothermic reaction and the reaction is unlikely to proceed. Is also supported by thermodynamic calculations. Therefore, ^A _ll 2 _Si 5 _{N 8} containing no Al ions is easily generated. On the other hand, the raw material compound of the present invention (a compound containing two or more elements other than nitrogen and oxygen among the elements constituting the formula [1]), particularly A ^l (alkaline earth metal essential for Sr) If the element) alloy and the like containing Al was used as a raw material, since always Al ions around the ^{a l} ions ^present, _a l 2 _Si 5 _{N 8} is less likely to generate.

Above aspects, ^and, from the viewpoint of _{A l 2 Si 5-x Al} x N of _{8-x O x} phase generation tends to occur at x ≦ 0.2, the starting compound of the present invention (the above formula [1] of the elements constituting the, preferably the number of moles of Al to a ^l of nitrogen and elements other than oxygen compound containing two or more) exceeds 0.2, more not less than 0.4 Preferably, it is 0.6 or more, more preferably 0.8 or more, and particularly preferably 0.9 or more. the value of x is increased the amount ^{of A l} ions are present to bind to the Al ion is not closed or Å order mixed If it is 0.2 or _{^{less, A l 2 Si 5-x}} Al x N 8-x O x (x ≦ 0.2) tends to increase. Moreover, when 1.2 is exceeded, since insufficient ^Al must be added and the process becomes complicated, 1.2 or less is preferable, and 1.1 or less is more preferable. A ^l of the metal and the nitride safe handling for Al element 1mol since if there is tricky, compounds having the above composition A ^l elements 1mol are most preferred. Further, if the starting compound of the present invention contains Si ^{is, A l: Al: Si =} 1: 1: 1 may be used a compound which is (molar ratio).

  Moreover, Si source may be contained in the raw material compound of this invention, and may be added as another compound. When the Si source is added as another compound, “other raw materials” containing Si can be used together with or in addition to the raw material compound of the present invention. The raw material compound of the present invention as described above may be produced by a known alloy production method (see Japanese Patent Application Laid-Open No. 2007-262574), and various metal elements are heated and produced by a solid phase reaction method. Also good. In the case of a known alloy manufacturing method, since the raw material compound of the present invention passes through a liquid phase in the manufacturing process, a fine component can be uniformly distributed due to a stirring effect, and thus a phosphor having high characteristics can be easily obtained. In the production method of the present invention, a metal element having a small blending ratio in the composition of the phosphor can be added as a single metal as another raw material to be described later. Examples of the simple metal include Eu and Ce.

Moreover, when producing the alloy accompanied by the peritectic reaction described above, solids of various metals such as nitrogen and argon are used at a temperature lower than the peritectic temperature (for example, a temperature of 600 ° C. or higher and 900 ° C. or lower in the Sr—Al system). It is also possible to produce an alloy by a solid phase reaction method by heating for 10 minutes to 12 hours in an inert atmosphere. The heating temperature at this time is preferably close to the peritectic temperature.
The raw material compound of the present invention is preferably used in the form of a powder having a desired particle size. The pulverization method for obtaining the powdery raw material compound of the present invention (powder of the raw material compound of the present invention. For example, an alloy powder) is not particularly limited, but is described in, for example, JP-A-2006-307182. It can be crushed by the method.

The powder of the raw material compound of the present invention needs to be adjusted in particle size depending on the activity of the metal element constituting the powder of the raw material compound of the present invention, and its weight median diameter D ₅₀ is usually 1 mm or less, The thickness is preferably 100 μm or less, more preferably 80 μm or less, particularly preferably 60 μm or less, and 0.1 μm or more, preferably 0.5 μm or more, particularly preferably 1 μm or more. Further, when the raw material compound powder of the present invention contains Sr, the reactivity with the atmospheric gas is high, so that the weight median diameter D ₅₀ of the raw material compound powder of the present invention is usually 5 μm or more, preferably 8 μm or more. More preferably, the thickness is 10 μm or more, and particularly preferably 13 μm or more. If the weight median diameter D ₅₀ is smaller than the above range, the rate of heat generation during the reaction such as nitriding tends to increase, so that the control of the reaction may be difficult. On the other hand, when the weight median diameter D ₅₀ is larger than the above range, the reaction such as nitriding inside the particles of the raw material compound of the present invention may be insufficient.

The weight-average median diameter D ₅₀ is, for example, obtained by measuring particle size distribution by laser diffraction scattering method, is a value determined from the mass-standard particle size distribution curve. The median diameter D ₅₀ is in this mass-standard particle size distribution curve, the accumulated value refers to the particle size value when the 50%.
The proportion of particles having a particle size of 10 μm or less contained in the powder of the raw material compound of the present invention is preferably 80% by weight or less, and the proportion of particles having a particle size of 45 μm or more is 40% by weight or less. preferable. The value of QD (Quartile Deviation, quadrant deviation) is not particularly limited, but it is usually preferably 0.8 or less. Here, QD is defined as QD = (D75−D25) / (D75 + D25) where the particle size values when the integrated values are 25% and 75% are denoted as D25 and D75, respectively. A small QD value means a narrow particle size distribution.

  When the raw material compound of the present invention has high activity depending on its composition or particle size and may spontaneously ignite in the air, for example, by the method described in JP-A-2008-7751, After the raw material compound is stabilized by partial nitriding, it can be used as a raw material. The partially nitrided raw material means a case where nitrogen is contained and metal remains. Moreover, the raw material compound of the present invention may be partially oxidized. The partially oxidized raw material means a case where oxygen is contained and metal remains.

(Other raw materials)
Other raw materials that can be used together with the raw material compound of the present invention and the raw material compound of the present invention include alkaline earth metal oxides (SrO, CaO, BaO, MgO), alkaline earth metal carbonates (SrCO _3). , CaCO ₃ , BaCO ₃ , MgCO ₃ ), Si ₃ N ₄ , Si imide compounds, SiO, SiO ₂ , Si ₂ N ₂ O, SiC, Al metal, Al ₂ O ₃ , Al (OH) ₃ , Al ₄ C ₃ , Sr ₃ Al ₂ N ₄ , Ca ₃ Al ₂ N ₄ , Ba ₃ Al ₂ N ₄ , Mg ₃ Al ₂ N ₄ , Sr ₃ AlN ₃ , Ca ₃ AlN ₃ , Ba ₃ AlN ₃ , Mg ₃ AlN ₃ , Eu ₂ O ₃ , EuF _{3 and the} like.

In the solid phase reaction method, the target organism can be obtained in a shorter reaction time as the raw material particle size is smaller and the contact area between the particles is larger. Therefore, the weight median diameter D ₅₀ of “other raw materials” is usually 100 μm or less, preferably 80 μm or less, particularly preferably 60 μm or less. If the particle size is too small, some of the other raw materials described above may undergo chemical changes such as absorption of moisture or carbon dioxide, or oxidation. Therefore, the weight median diameter D ₅₀ of “other raw materials” is usually 0.1 μm or more, preferably 0.5 μm or more, and particularly preferably 1 μm or more.

(Baking aid)
If necessary, a firing aid may be used. The constituent elements of the compound serving as the firing aid may or may not be included as the composition of the formula [1]. That is, when a firing aid is used, the firing aid may be present together with the phosphor material in the firing step.
By using the firing aid, the firing aid compound acts as a flux to promote the reaction, and a more uniform phosphor can be obtained. In addition, since the flux, that is, the liquid phase is involved in the chemical reaction, the diffusion of atoms is accelerated, so that the firing time for obtaining the phosphor can be shortened and the amount of energy used can be reduced.

As typical firing aids, alkali metal, alkaline earth metal or rare earth element halides (M ¹ X, M ² X ₂ or LnX ₃ etc., where M ¹ is an alkali such as Li, Na, K etc. Metal element, M ² is an alkaline earth metal element such as Mg, Ca, Sr, Ba, Ln is a rare earth element such as Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb, X Is a halogen such as F, Cl, Br, or I.). Among these, a compound that is liquid at the maximum temperature of the following heating step and has a low vapor pressure can be arbitrarily used.

  The amount used in the case of using a firing aid as the flux may be added as required, but is preferably 1% by weight or more based on 1 unit weight of the composition of the formula [1]. When the amount used is increased, the product aggregates or the sintered density becomes high, which may make it difficult to carry out the following post-treatment step. Therefore, the upper limit of the amount used is the composition of the formula [1]. It is preferably 15% by weight or less with respect to 1 unit weight.

(Prepared composition)
In the method for producing the phosphor of the present invention, it is preferable that the above-described phosphor raw material of the present invention and other raw materials are charged with each raw material so as to have a composition represented by the following [1]. That is, in the conventional method for producing a phosphor using a phosphor raw material alloy as a raw material, it has been preferable that the oxygen content of the raw material and the produced phosphor is low. It is preferable to contain oxygen both in the composition (the following formula [1]) and in the finished composition (the following formula [2]).
The following formula [1]:

^{_{(A l 1-xl, Z}} l xl) al D l bl E l cl N l dl O l el [1]
(In the formula [1], A ¹ represents an alkaline earth metal element in which Sr is essential, Z ^l represents one or more activator elements in which Eu or Ce is essential, and D ^l is essential to Si. a tetravalent metal element and, ^{E l} represents a trivalent metal element essentially containing Al, xl is a number satisfying 0.0001 ≦ xl ≦ 0.20, al, bl, cl, dl And el are 0.7 ≦ al ≦ 1.3, 2.5 ≦ bl ≦ 4.0, 1.0 ≦ cl ≦ 3.0, 3.5 ≦ (bl + cl) /al≦6.0, respectively. Numbers satisfying 0.1 ≦ dl ≦ 7.0 and 0 <el ≦ 2.0 are shown.)
As described above, in the formula [1], “A ¹ ” represents an alkaline earth metal element that essentially requires Sr, and has the same meaning as “A” in formula [2] described later.

In the above formula [1], “Z ^l ” represents an activator element that essentially requires europium or cerium, and is synonymous with “Z” in formula [2] described below.
In the above formula [1], “D ^l ” represents a tetravalent metal element that essentially requires Si, and has the same meaning as “D” in formula [2] described later.
In the above formula [1], “E ^l ” represents a trivalent metal element that essentially requires Al, and is synonymous with “E” in formula [2] described later.

In the formula [1], “N” represents nitrogen and has the same meaning as “E” in formula [2] described later.
In the formula [1], “O” represents oxygen and has the same meaning as “E” in formula [2] described later.
Moreover, the phosphor raw material used in the production method of the present invention is within the range that does not affect the effects of the present invention in addition to the constituent elements of A ^l , Eu, D ^l , E ^l , N and O described above. An element inevitably mixed, for example, an impurity element may be included.

In said Formula [1], "x" shows the molar ratio of an activator element (Z), and is synonymous with "x" in below-mentioned Formula [2].
In the formula [1], "in the" al "indicates the sum of the molar ratio of the activator element (Z) (alkaline earth metal element essentially including Sr) A ^l elemental formula below [2] It is synonymous with “a”.

In the formula [1], "bl" indicates the molar ratio of D ^l elements (tetravalent metal elements essentially containing Si). b is a number satisfying 2.5 ≦ bl ≦ 4.0, preferably 2.6 or more, more preferably 2.7 or more, further preferably 2.8 or more, and particularly preferably 2.85 or more. Moreover, it is preferably 3.9 or less, more preferably 3.8 or less, still more preferably 3.7 or less, and particularly preferably 3.65 or less.

In the formula [1], “cl” represents the molar ratio of the ^El element (trivalent metal element in which Al is essential), and is synonymous with “x” in the formula [2] described later.
Further, (bl + cl) / al is the ratio of the sum of the molar ratio of ^{D l} elements and ^{E l} element to the sum of the molar ratio of A element and activator element, typically, 3.5 ≦ (bl + cl) / al The number satisfies ≦ 6.0. Further, (bl + cl) / al is preferably 3.7 or more, more preferably 3.9 or more, still more preferably 4.1 or more, and preferably 5.65 or less, more preferably 5.5. Hereinafter, it is more preferably 5.35 or less.

In the above formula [1], “dl” represents the molar ratio of N element (nitrogen). dl is a number satisfying 0.1 ≦ d ≦ 7.0, preferably 0.8 or more, more preferably 1.8 or more, still more preferably 2.8 or more, and particularly preferably 3.8 or more. Also, it is preferably 6.9 or less, more preferably 6.8 or less, and particularly preferably 6.7 or less.
In the above formula [1], “el” represents the molar ratio of the O element (oxygen) and is synonymous with “e” in formula [2] described later. Preferably it is 0.1 or more, More preferably, it is 0.3 or more, More preferably, it is 0.6 or more, Preferably it is 1.9 or less, More preferably, it is 1.8 or less, More preferably, it is 1.7 or less.

In addition, the raw material corresponding to the element which comprises the fluorescent substance of this invention may use only 1 type, respectively, and may use 2 or more types together by arbitrary combinations and a ratio. That is, in order to obtain a desired phosphor composition, necessary elements other than the above-mentioned “raw material compound of the present invention” may be added as other raw materials as necessary.
As a combination of the raw material compound of the present invention and other raw materials, Sr ₈ Al ₇ , SrAl ₂ and / or SrAl ₄ are used as the raw material compound of the present invention, and Al ₂ O ₃ , Si ₃ N ₄ , And Eu ₂ O ₃ are used.

The N element and the O element are basically derived from the raw material compound, but may be taken in from the heating atmosphere.
In addition, when the “raw material compound of the present invention” is an alloy, the calorific value due to the nitriding reaction may increase, thereby impairing the phosphor synthesis reaction. Therefore, it is preferable to appropriately adjust the alloy composition.
Hereinafter, a method for producing a phosphor using the raw material compound of the present invention will be described. JP-A-2006-307182, JP-A-2008-7751 and the like disclose a method for producing a phosphor using an alloy as a phosphor material.

[Mixing process]
The above-described phosphor raw material compound of the present invention, other raw materials, etc. (hereinafter sometimes simply referred to as “phosphor raw material”) are weighed so as to have the composition of the formula [1], and then a known powder. It is preferable to mix thoroughly using a mixing method. When alloy raw materials are used, it is preferable to perform mixing operations under an inert atmosphere as necessary to prevent unnecessary chemical and physical reactions.

[Baking process]
The firing step is performed by filling the phosphor material described above into a heating container such as a crucible or a tray and heating it in a nitrogen-containing atmosphere. Specifically, the following procedure is used.
That is, first, a phosphor material is filled in a container. The material of the container used here is arbitrary as long as the effect of the production method of the present invention can be obtained, and examples thereof include boron nitride, alumina, molybdenum, silicon nitride, carbon, aluminum nitride, and tungsten. Of these, boron nitride and alumina are preferable because of their excellent corrosion resistance. In addition, the said material may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  Moreover, the shape of the container used here is arbitrary as long as the effect of the manufacturing method of this invention is acquired. For example, the bottom surface of the container may be a shape without a corner such as a circle or an ellipse, or a polygon such as a triangle or a rectangle, and the height of the container may be referred to as a heating device (“heating furnace”). ) As long as it enters, and may be low or high. Among these, it is preferable to select a shape with good heat dissipation.

A container filled with the phosphor material is placed in a heating device. The heating device used here is arbitrary as long as the effects of the production method of the present invention can be obtained, but a device capable of controlling the atmosphere and gas flow rate in the device is preferable, and a device capable of controlling the pressure is also preferable. For example, a normal pressure atmosphere furnace, a resistance heating type vacuum pressure atmosphere heat treatment furnace, a hot isostatic press (HIP) and the like are preferable.
Moreover, it is preferable to circulate the nitrogen-containing gas in the heating device and sufficiently replace the system with the nitrogen-containing gas before starting the heating. If necessary, a nitrogen-containing gas may be circulated after the system is evacuated. The temperature at which the nitrogen-containing gas is circulated is preferably 1000 ° C. or less. More preferably, the raw material compound of the present invention and the mixture of the raw material compound of the present invention and other raw materials are at a temperature lower than the temperature at which nitrogen is taken from the nitrogen-containing gas. More preferably, the temperature is lower than the temperature at which the raw material compound of the present invention and the mixture of the raw material compound of the present invention and other raw materials start to react in the nitrogen-containing gas. These temperatures can be estimated by thermal analysis such as thermogravimetry (TG), differential thermal analysis (DTA), or differential scanning calorimetry (DSC). In addition, for the raw material compound of the present invention heated at a predetermined temperature, and a mixture of the raw material compound of the present invention and other raw materials, changes in the powder X-ray diffraction pattern before and after heating were compared, and at the temperature at which the change was observed. You can also estimate. In addition, it may be defined as a temperature at which any compound among the used raw materials undergoes changes such as decomposition and melting.

  Examples of the nitrogen-containing gas used in the heat treatment include a gas containing a nitrogen element, such as nitrogen, ammonia, or a mixed gas of nitrogen and hydrogen. In addition, only 1 type may be used for nitrogen-containing gas and it may use 2 or more types together by arbitrary combinations and a ratio. The oxygen concentration in the system affects the oxygen content of the phosphor to be produced, and if the content is too high, the target product and high luminescence cannot be obtained. Therefore, the oxygen concentration in the nitriding atmosphere is preferably as low as possible, Usually 1000 ppm or less, preferably 100 ppm or less, more preferably 10 ppm or less. Further, if necessary, an oxygen getter such as carbon, molybdenum, or aluminum nitride may be placed in the in-system heating portion to lower the oxygen concentration. In addition, an oxygen getter may be used only by 1 type and may use 2 or more types together by arbitrary combinations and a ratio. In addition, the moisture concentration in the system also affects the oxygen content of the phosphor to be produced. If the content is too high, the target product and high light emission cannot be obtained. Preferably, it is usually 1000 ppm or less, preferably 100 ppm or less, more preferably 10 ppm or less.

  The nitriding treatment of the “raw material compound of the present invention” is performed by heating the phosphor raw material in a state of being filled or flowing with a nitrogen-containing gas. Although it may be in any state of atmospheric pressure or pressurization, it is preferable from the viewpoint of manufacturing cost reduction to be near atmospheric pressure or about 0.92 MPa or less, and more preferably near atmospheric pressure.

In addition, the temperature at which the phosphor material is heated is relatively low in both the vicinity of atmospheric pressure and the pressurization of about 0.92 MPa or less, specifically, 1300 ° C. or more, preferably 1350 ° C. or more. More preferably, heating is performed in a temperature range of 1400 ° C. or higher and 1500 ° C. or lower.
The heating time (holding time at the maximum temperature) during the heat treatment may be a time required for the reaction between the phosphor raw material and nitrogen, but is usually 1 minute or more, preferably 10 minutes or more, more preferably 30 minutes or more, More preferably, it is 60 minutes or more. If the heating time is shorter than 1 minute, the nitriding reaction may not be completed and a phosphor having high characteristics may not be obtained. The upper limit of the heating time is determined from the viewpoint of production efficiency, and is usually 24 hours or less.

In the heating process of the present invention, since the ratio of highly reactive alkaline earth metal elements to the entire raw material is small, the phosphor characteristics are generally less likely to deteriorate due to rapid reaction progress. Therefore, the heating rate can be selected as necessary in the range of 0.01 ° C./min to 50 ° C./min. However, from the viewpoint of production efficiency, it should be 5 ° C./min to 30 ° C./min. Is preferred. However, when a large amount of the powder of the phosphor raw material of the present invention is heated at once, there is a possibility that the nitriding reaction proceeds rapidly and the characteristics of the phosphor of the present invention are deteriorated. In that case, in order to suppress the rapid progress of the nitriding reaction, the rate of temperature increase at 900 ° C. to 1200 ° C. may be 0.01 ° C./min or more and 2 ° C./min or less.
In the production method of the present invention, when a nitride (for example, a nitride containing a crystal phase represented by the formula [2]) coexists in addition to the phosphor raw material described above, the rapid progress of the nitriding reaction is suppressed. be able to.

(Reheating process)
The phosphor obtained by the heat treatment step may be subjected to a reheating step as necessary, and may be subjected to a heat treatment (reheat treatment) again to grow particles. Thereby, the characteristics of the phosphor may be improved, for example, the particles grow and the phosphor can obtain high light emission.
In this reheating step, the material may be once cooled to room temperature and then heated again. The heating temperature in the reheating treatment is usually 800 ° C. or higher, preferably 900 ° C. or higher, more preferably 1000 ° C. or higher, and usually 1600 ° C. or lower, preferably 1500 ° C. or lower, more preferably 1400 ° C. or lower. . When heated below 800 ° C., the effect of growing phosphor particles tends to be small. On the other hand, when heating at a temperature exceeding 1600 ° C., not only wasteful heating energy is consumed but also the phosphor may be decomposed. Further, in order to prevent the phosphor from being decomposed, the pressure of nitrogen that is a part of the atmospheric gas is made extremely high, so that the manufacturing cost tends to increase.

  The atmosphere during the reheating treatment of the phosphor is basically preferably a nitrogen-containing gas atmosphere, an inert gas-containing atmosphere, or a reducing gas-containing atmosphere. In addition, only 1 type may be used for an inert gas and reducing gas, respectively, and 2 or more types may be used together by arbitrary combinations and a ratio. The oxygen concentration in the atmosphere is usually 1000 ppm or less, preferably 100 ppm or less, more preferably 10 ppm or less. If reheating treatment is performed in an oxidizing atmosphere such as in an oxygen-containing gas or in the air where the oxygen concentration exceeds 1000 ppm, the phosphor may be oxidized and the target phosphor may not be obtained. However, it is preferable to use an atmosphere containing a trace amount of oxygen of 0.1 ppm to 10 ppm because phosphors can be synthesized at a relatively low temperature.

The pressure condition during the reheating treatment is preferably set to a pressure equal to or higher than the atmospheric pressure in order to prevent oxygen from being mixed in the atmosphere. If the pressure is too low, a large amount of oxygen may be mixed in if the heating furnace is poorly sealed as in the nitriding process described above, and a phosphor having high characteristics may not be obtained.
The heating time (retention time at the maximum temperature) during the reheating treatment is usually 1 minute or more, preferably 10 minutes or more, more preferably 30 minutes or more, and usually 100 hours or less, preferably 24 hours or less, More preferably, it is 12 hours or less. If the heating time is too short, particle growth tends to be insufficient. On the other hand, if the heating time is too long, useless heating energy tends to be consumed, and nitrogen may be desorbed from the surface of the phosphor and the light emission characteristics may deteriorate.

[Post-processing process]
The obtained phosphor may be used for various applications after performing post-treatment steps such as a dispersion step, a classification step, a washing step, and a drying step, if necessary.
(Dispersion process)
In the dispersion step, a mechanical force is applied to the phosphor that has been agglomerated due to particle growth, sintering, etc. during the heating step, and is crushed. For example, a method such as crushing with an air current such as a jet mill or crushing with a medium such as a ball mill or a bead mill can be used.

(Classification process)
The phosphor powder dispersed by the above method can be adjusted to a desired particle size distribution by performing a classification step. For classification, for example, a sieving apparatus using a mesh such as a vibratory screen or a shifter, an inertia classifier such as an air separator or a water tank apparatus, or a centrifugal classifier such as a cyclone can be used.

(Washing process)
In the washing step, the phosphor is roughly pulverized with, for example, a jaw crusher, a stamp mill, a hammer mill or the like, and then used with a neutral or acidic solution (hereinafter sometimes referred to as “cleaning medium”). Wash by technique.
By performing the washing step, an impurity phase other than the target product is removed, and a high-quality phosphor can be obtained.

(Drying process)
After the washing, the phosphor can be dried until it is free from adhering moisture and can be used. As an example of specific operation, the phosphor slurry that has been washed may be dehydrated with a centrifugal separator or the like, and the obtained dehydrated cake may be filled in a drying tray. Then, it dries in the temperature range of 100 ° C. to 200 ° C. until the water content becomes 0.1% by weight or less. The obtained dried cake is passed through a sieve or the like and lightly crushed to obtain a phosphor.
In many cases, the phosphor is used as a powder and is used in a state dispersed in another dispersion medium. Therefore, in order to facilitate these dispersion operations, various surface treatments are performed on phosphors as a normal method among those skilled in the art. In the case of the phosphor that has been subjected to such surface treatment, it is appropriate to understand that the stage before the surface treatment is performed is the phosphor according to the present invention.

[2. Phosphor]
<Crystal structure>
The phosphor of the present invention has a skeletal structure composed of Si, Al, N, and O, and has a crystal structure in which Sr sites exist in the voids.
(Crystal system)
The crystal system of the crystal phase contained in the phosphor of the present invention is orthorhombic or monoclinic, and is preferably orthorhombic.

The phosphor of the present invention preferably has a crystal structure similar to that of SrAlSi ₄ N _{7. As} the space group of the crystal phase, “International Tables for Crystallography (Third, Revised Edition), Volume A Space-Group Symptom”. 62 [Pnma], 33 [Pna2 ₁ ], 19 [P2 ₁ 2 ₁ 2 ₁ ], 7 [Pc], or 4 [P2 ₁ ]
It is preferable that it belongs to any one of the above, and the one belonging to No. 33 [Pna2 ₁ ] is most preferable.
The space group is determined by electron diffraction or convergent electron diffraction.

<Composition of phosphor>
The phosphor of the present invention has the following formula [2]:
(A _1-x , Z _x ) _a D _b E _c N _d O _e [2]
(In the formula [2], A represents an alkaline earth metal element essential for Sr, Z represents one or more activator elements essential for Eu or Ce, and D required Si for 4 E represents a trivalent metal element in which Al is essential, x represents a number satisfying 0.0001 ≦ x ≦ 0.20, and a, b, c, d, and e are 0.7 ≦ a ≦ 1.3, 2.5 ≦ b ≦ 4.0, 1.0 ≦ c ≦ 3.0, 3.5 ≦ (b + c) /a≦6.0, 5.0 ≦, respectively. (The number satisfies d ≦ 7.0, 0 <e ≦ 2.0, 6.5 ≦ (d + e) /a≦7.5.)
The crystal phase which has the composition represented by these is included. That is, the phosphor of the present invention has a (A, Eu) (Si, Al) ₅ (N, O) ₇ phase that requires oxygen (where A represents an alkaline earth metal element that requires Sr). .).

As described above, in the formula [2], “A” represents an alkaline earth metal element in which Sr is essential. The proportion of Sr to the entire element A is preferably 50 mol% or more, more preferably 70 mol% or more, and particularly preferably 90 mol% or more. In addition to Sr, the A element may include alkaline earth metal elements such as calcium (Ca) and barium (Ba).
In the formula [2], when Ca is contained as the A element, the ratio of Ca to the entire A element is preferably 0.001 mol% or more and 80 mol% or less, more preferably 0.01 mol% or more, More preferably 1 mol% or more, particularly preferably 5 mol% or more, most preferably 7 mol% or more, preferably 65 mol% or less, more preferably 50 mol% or less, and further preferably 35 mol% or less. Especially preferably, it is 20 mol% or less.

When the proportion of Ca is in the above range, the lattice volume becomes a more appropriate size, and the skeletal structure can take a stable state without distortion.
In said Formula [2], "Z" shows the activator element which has europium or cerium essential. In addition to the activator europium (Eu) or cerium (Ce), other activators include titanium (Ti), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), tin ( Sn), antimony (Sb), bismuth (Bi), praseodymium (Pr), neodymium (Nd), samarium (Sm), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium ( It may be substituted with at least one metal element selected from the group consisting of Tm) and ytterbium (Yb). Of these other activators, at least one metal element selected from the group consisting of Pr, Sm, Tb and Yb is preferred.

The proportion of europium (Eu) or cerium (Ce) with respect to the entire activator element is preferably 50 mol% or more, more preferably 70 mol% or more, and preferably 90 mol% or more. Further, the proportion of europium (Eu) with respect to the entire activator element is preferably 50 mol% or more, more preferably 70 mol% or more, and more preferably 90 mol% or more.
In the above formula [2], “D” represents a tetravalent metal element in which Si is essential. The element D may contain germanium (Ge), tin (Sn), or the like within a range that does not affect the properties of the obtained phosphor. The proportion of Si with respect to the entire D element is preferably 50 mol% or more, more preferably 70 mol% or more, and particularly preferably 90 mol% or more. If the ratio of Si to the entire D element is too small, impurities are generated, and it tends to be difficult to obtain a phosphor having the target composition.

  In the formula [2], “E” represents a trivalent metal element in which Al is essential. The element E may contain boron (B), gallium (Ga), or the like within a range that does not affect the properties of the obtained phosphor. The proportion of Al to the entire E element is preferably 50 mol% or more, more preferably 70 mol% or more, and particularly preferably 90 mol% or more. If the ratio of Al to the entire E element is too small, impurities are generated, and it tends to be difficult to obtain a phosphor having the target composition.

In the formula [2], “N” represents nitrogen. The N element only needs to contain nitrogen as a main component, and may contain halogen such as fluorine (F) and chlorine (Cl) within a range that does not affect the characteristics of the obtained phosphor.
In the formula [2], “O” represents oxygen. The O element only needs to contain oxygen as a main component, and may contain halogen such as fluorine (F) and chlorine (Cl) within a range that does not affect the characteristics of the obtained phosphor.

  Moreover, the phosphor of the present invention includes elements inevitably mixed within a range that does not affect the effects of the present invention, in addition to the above-described constituent elements of A, Z, D, E, N, and O. For example, an impurity element may be included. Furthermore, the phosphor of the present invention inevitably lacks any of the above-described constituent elements of A, Z, D, E, N, and O within a range that does not affect the effects of the present invention. You may do it.

  In said Formula [2], "x" shows the molar ratio of an activator element (Z). x is a number satisfying 0.0001 ≦ x ≦ 0.20, preferably 0.001 or more, more preferably 0.005 or more, still more preferably 0.01 or more, and preferably 0.19. In the following, it is more preferably 0.17 or less, further preferably 0.15 or less, particularly preferably 0.12 or less.

If the value of x is too large, the luminance tends to decrease due to concentration quenching, and if it is too small, the absorption efficiency tends to decrease. Accordingly, the luminance of the phosphor tends to decrease.
In said Formula [2], "a" shows the sum of the molar ratio of A element (alkaline earth metal element which makes Sr essential), and activator element (Z). a is usually a number satisfying 0.7 ≦ a ≦ 1.3, preferably 0.8 or more, more preferably 0.9 or more, particularly preferably 0.95 or more, and preferably 1. It is 2 or less, more preferably 1.1 or less, and particularly preferably 1.05 or less.

The molar ratio of “a” and the moles of “b” and “c” described below are within the scope of the present invention, that is, D element (a tetravalent metal element in which Si is essential) and E element (Al is essential). By making the ratio of the trivalent metal element to be in a specific range, the element A (alkaline earth metal element in which Sr is essential) is surely dissolved, and a phosphor exhibiting the above-described effects is obtained. Can do.
In the above formula [2], “b” represents the molar ratio of the D element (a tetravalent metal element in which Si is essential). b is a number satisfying 2.5 ≦ b ≦ 4.0, preferably 2.6 or more, more preferably 2.7 or more, more preferably 2.8 or more, and particularly preferably 2.85 or more. Also, it is preferably 3.9 or less, more preferably 3.8 or less, still more preferably 3.7 or less, and particularly preferably 3.65 or less.

  In the formula [2], “c” represents the molar ratio of the E element (a trivalent metal element in which Al is essential). c is a number satisfying 1.0 ≦ c ≦ 3.0, preferably 1.1 or more, more preferably 1.2 or more, still more preferably 1.3 or more, and preferably 2.7. In the following, it is more preferably 2.4 or less, further preferably 2.35 or less, particularly preferably 2.2 or less.

  Further, (b + c) / a is the ratio of the sum of the molar ratio of the D element and the E element to the sum of the molar ratio of the A element and the activator element, and is generally 3.5 ≦ (b + c) / a ≦ 6 It is a number satisfying .0. Further, (b + c) / a is preferably 4.25 or more, more preferably 4.5 or more, still more preferably 4.75 or more, and preferably 5.75 or less, more preferably 5.5. Hereinafter, it is more preferably 5.25 or less.

In said Formula [2], "d" shows the molar ratio of N element (nitrogen). d is a number satisfying 5.0 ≦ d ≦ 7.0, preferably 5.25 or more, more preferably 5.5 or more, particularly preferably 5.75 or more, and preferably 6.9 or less, More preferably, it is 6.8 or less, Most preferably, it is 6.7 or less.
In said Formula [2], "e" shows the molar ratio of O element (oxygen). e is a number satisfying 0 <e ≦ 2.0, preferably 0.1 or more, more preferably 0.3 or more, further preferably 0.6 or more, and preferably 1.9 or less, more preferably Is 1.8 or less, more preferably 1.7 or less.

Further, (d + e) / a is the ratio of the sum of the molar ratios of N element (nitrogen) and O element (oxygen) to the sum of the molar ratios of element A and activator element, and usually 6.5 ≦ ( d + e) /a≦7.5. Further, (d + e) / a is preferably 6.7 or more, more preferably 6.8 or more, particularly preferably 6.9 or more, and preferably 7.3 or less, more preferably 7.2 or less. Particularly preferably, it is 7.1 or less.
As described above, in the phosphor of the present invention, the molar ratio of a, the molar ratio of d, and the molar ratio of e are within the above ranges, that is, a, b, c, (b + c) / a, d, e, (d + e ) / A in the above range makes it possible to obtain a phosphor exhibiting the effects described above by reliably dissolving the A element.

<Characteristics of phosphor>
(Peak emission wavelength)
The phosphor of the present invention is usually 500 nm or more, preferably 510 nm or more, more preferably 520 nm or more, and usually has an emission peak in a wavelength range of 650 nm or less, preferably 630 nm or less. That is, it has light emission of a light wavelength corresponding to yellow to red.
Since the phosphor of the present invention has a wide half-value width of the emission peak, when used in combination with a blue LED, light emission with good color rendering can be obtained with only one type of phosphor. In addition to the phosphor of the present invention, if a light emitting device is formed by combining a blue to yellow-green phosphor, a red phosphor, or the like, a light emitting device that emits light of higher color rendering can be obtained.

(CIE chromaticity coordinates)
The x value of the CIE chromaticity coordinate of the phosphor of the present invention is usually 0.400 or more, preferably 0.450 or more, more preferably 0.500 or more, and usually 0.660 or less, preferably 0.630 or less. More preferably, it is 0.610 or less, More preferably, it is 0.590 or less. The y value of the CIE chromaticity coordinates of the phosphor of the present invention is usually 0.300 or more, preferably 0.350 or more, more preferably 0.400 or more, and usually 0.550 or less, preferably 0.8. It is 525 or less, more preferably 0.500 or less.
When the CIE chromaticity coordinates are in the above range, a light emission color with good color rendering can be obtained.

(Excitation wavelength)
The phosphor of the present invention has an excitation peak in a wavelength range of usually 300 nm or more, preferably 330 nm or more, more preferably 360 nm or more, and usually 500 nm or less, preferably 480 nm or less, more preferably 460 nm or less. That is, it is excited by light in the ultraviolet to blue region.

(Temperature extinction characteristics (emission intensity maintenance rate))
The phosphor of the present invention also has excellent temperature characteristics. Specifically, the ratio of the emission peak intensity value in the emission spectrum diagram at 100 ° C. to the emission peak intensity value in the emission spectrum diagram at 25 ° C. when light having a peak at a wavelength of 405 nm is usually 50 % Or more, preferably 60% or more, more preferably 70% 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 a temperature change.

(Quantum efficiency)
The external quantum efficiency (η _o ) of the phosphor of the present invention is usually 40% or more, preferably 50 or more, more preferably 60% or more. The higher the external quantum efficiency, the better. The lower the external quantum efficiency, the lower the light emission efficiency.
The internal quantum efficiency, the external quantum efficiency, the absorption efficiency, and the like can be measured by, for example, the methods described in paragraphs [0064] to [0076] and [0265] to [0276] of JP-A-2008-285658. .

(Particle size)
The phosphor of the present invention usually has a fine particle form. More specifically, the weight-average median diameter _{D 50} is usually 2μm or more, preferably 5μm or more, and usually 30μm or less, preferably fine particles of the range 20 [mu] m. When the weight-average median diameter D ₅₀ is too large, for example, tend to dispersibility becomes poor in the resin which is used as a sealing material described later, they tend to be too small and the low luminance. Incidentally, the weight-average median diameter D ₅₀ can be measured in a similar manner to that described above.

[3. Use of phosphor]
The phosphor of the present invention can be used for any application using the phosphor. In addition, the phosphor of the present invention can be used alone, but two or more kinds of phosphors can be used together, or a phosphor mixture of any combination using the phosphor of the present invention and other phosphors in combination. Can also be used.

The phosphor of the present invention can be used as a phosphor-containing composition by mixing with a known liquid medium (for example, a silicone compound).
In addition, the phosphor obtained by the present invention can be suitably used for various light-emitting devices by combining with a light source that emits ultraviolet light, taking advantage of the property that it can be excited by ultraviolet light.
The emission color of the light-emitting device is not limited to purple or white, but by appropriately selecting the combination and content of phosphors, light emission that emits light in any color, such as light bulb color (warm white) or pastel color The device can be manufactured. The light-emitting device thus obtained can be used as a light-emitting portion (particularly a liquid crystal backlight) or an illumination device of an image display device.

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

(Phosphor)
There is no restriction | limiting in the kind of fluorescent substance of this invention contained in the said fluorescent substance containing composition, It can select arbitrarily. Moreover, the fluorescent substance of this invention contained in a fluorescent substance containing composition may be only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Furthermore, the phosphor-containing composition 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.

(Liquid medium)
The kind of liquid medium used for the phosphor-containing composition is not particularly limited, and a curable material that can be molded over the semiconductor light emitting element can be used. The curable material is a fluid material that is cured by performing some kind of curing treatment. Here, the fluid state means, for example, a liquid state or a gel state. The curable material is not particularly limited as long as it secures the role of guiding the light emitted from the solid light emitting element to the phosphor. Moreover, only 1 type may be used for a curable material and it may use 2 or more types together by arbitrary combinations and a ratio. Therefore, as the curable material, any of inorganic materials, organic materials, and mixtures thereof can be used.

As the inorganic material, for example, a solution obtained by hydrolytic polymerization of a solution containing a metal alkoxide, a ceramic precursor polymer or a metal alkoxide by a sol-gel method, or a combination thereof is solidified (for example, a siloxane bond). Inorganic materials having
On the other hand, examples of the organic material include a thermosetting resin and a photocurable resin. Specific examples include (meth) acrylic resins such as poly (meth) acrylic acid methyl; styrene resins such as polystyrene and styrene-acrylonitrile copolymers; polycarbonate resins; polyester resins; phenoxy resins; butyral resins; Cellulose resins such as cellulose acetate and cellulose acetate butyrate; epoxy resins; phenol resins; silicone resins and the like.

Among these curable materials, it is preferable to use a silicon-containing compound that is less deteriorated with respect to light emitted from the semiconductor light-emitting element and is excellent in alkali resistance, acid resistance, and heat resistance. A silicon-containing compound is a compound having a silicon atom in the molecule, organic materials such as polyorganosiloxane (silicone compounds), inorganic materials such as silicon oxide, silicon nitride, and silicon oxynitride, and borosilicates and phosphosilicates. Examples thereof include glass materials such as salts and alkali silicates. Among these, silicone materials are preferable from the viewpoints of transparency, adhesion, ease of handling, and excellent mechanical and thermal stress relaxation characteristics.
The silicone-based material usually refers to an organic polymer having a siloxane bond as a main chain, and for example, condensation-type, addition-type, improved sol-gel type, photo-curing type silicone-based materials can be used.

  As the condensation type silicone-based material, for example, semiconductor light-emitting device members described in JP-A-2007-112973 to 112975, JP-A-2007-19459, JP-A-2008-34833, and the like can be used. Condensation-type silicone materials have excellent adhesion to packages, electrodes, and light-emitting elements used in semiconductor light-emitting devices, so the addition of adhesion-improving components can be minimized, and crosslinking is mainly due to siloxane bonds. There is an advantage of excellent heat resistance and light resistance.

  Examples of the addition-type silicone material include potting silicone materials described in JP-A-2004-186168, JP-A-2004-221308, JP-A-2005-327777, JP-A-2003-183881, Organically modified silicone materials for potting described in JP-A-2006-206919, silicone materials for injection molding described in JP-A-2006-324596, silicone materials for transfer molding described in JP-A-2007-231173, etc. Can be suitably used. The addition-type silicone material has advantages such as a high degree of freedom in selection such as a curing speed and a hardness of a cured product, a component that does not desorb during curing, hardly shrinking due to curing, and excellent deep part curability.

  Moreover, as an improved sol-gel type silicone material that is one of the condensation types, for example, the silicone materials described in JP-A-2006-077234, JP-A-2006-291018, JP-A-2007-119569 and the like can be used. It can be used suitably. The improved sol-gel type silicone material has an advantage that it has a high degree of crosslinking, heat resistance, light resistance and durability, and is excellent in the protective function of a phosphor having low gas permeability and low moisture resistance.

As the photocurable silicone material, for example, silicone materials described in JP2007-131812A, JP2007-214543A, and the like can be suitably used. The ultraviolet curable silicone material has advantages such as excellent productivity because it cures in a short time, and it is not necessary to apply a high temperature for curing, so that the light emitting element is hardly deteriorated.
These silicone materials may be used alone, or a mixture of a plurality of silicone materials may be used if curing inhibition does not occur when mixed.

(Content of liquid medium and phosphor)
The content of the liquid medium is arbitrary as long as the effect of the present invention is not significantly impaired, but is usually 25% by mass or more, preferably 40% by mass or more, based on the entire phosphor-containing composition of the present invention. Usually, it is 99 mass% or less, Preferably it is 95 mass% or less, More preferably, it is 80 mass% 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, when there is too little liquid medium, fluidity | liquidity may fall and it may become difficult to handle.

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

  Although the content rate of the fluorescent substance in a fluorescent substance containing composition is arbitrary unless the effect of this invention is impaired remarkably, it is 1 mass% or more normally with respect to the whole fluorescent substance containing composition of this invention, Preferably it is 5 It is at least mass%, more preferably at least 20 mass%, usually at most 75 mass%, preferably at most 60 mass%. The proportion of the phosphor of the present invention in the phosphor in the phosphor-containing composition is also arbitrary, but is usually 30% by mass or more, preferably 50% by mass or more, and usually 100% by mass or less. If the phosphor content in the phosphor-containing composition is too high, the flowability of the phosphor-containing composition may be inferior and difficult to handle, and if the phosphor content is too low, the light emission efficiency of the light-emitting device decreases. There is a tendency.

(Other ingredients)
In the phosphor-containing composition, unless the effect of the present invention is significantly impaired, in addition to the phosphor and the liquid medium, other components such as metal oxide for adjusting the refractive index, diffusing agent, filler, viscosity adjustment You may contain additives, such as an agent and a ultraviolet absorber. Only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

[5. Light emitting device]
A light-emitting device of the present invention includes a first light-emitting body (excitation light source) and a second light-emitting body that can emit visible light by converting light from the first light-emitting body into visible light. The above-mentioned [1. It contains a first phosphor containing one or more of the phosphors of the present invention described in the section [Phosphor].

Preferable specific examples of the phosphor of the present invention used in the light emitting device of the present invention include [1. Examples thereof include the phosphor of the present invention described in the “Phosphor” column and the phosphors used in the respective Examples in the “Example” column described later. In addition, any one of the phosphors of the present invention may be used alone, or two or more may be used in any combination and ratio.
The light-emitting device of the present invention has a first light emitter (excitation light source), and at least the phosphor of the present invention is used as the second light emitter. It is possible to arbitrarily adopt the apparatus configuration. A specific example of the device configuration will be described later.

Among the light emitting devices of the present invention, in particular, as a white light emitting device, specifically, an excitation light source as described later is used as the first light emitter, and in addition to the phosphor of the present invention, blue fluorescence as described later is emitted. Phosphor that emits light (hereinafter referred to as “blue phosphor” as appropriate), phosphor that emits green fluorescence (hereinafter referred to as “green phosphor” as appropriate), phosphor that emits red fluorescence (hereinafter referred to as “red phosphor” as appropriate) And a known phosphor such as a phosphor that emits yellow fluorescence (hereinafter referred to as “yellow phosphor” as appropriate) is used in any combination, and a known apparatus configuration is obtained.
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.

<Configuration of light emitting device>
(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 emission peak wavelength of the first illuminant is not particularly limited as long as it overlaps with the absorption wavelength of the second illuminant described later, and an illuminant having a wide emission wavelength region can be used. Usually, a light emitter having an emission wavelength from the ultraviolet region to the blue region is used.
The specific value of the emission peak wavelength of the first illuminant is usually 300 nm or more, preferably 330 nm or more, more preferably 360 nm or more, and usually 500 nm or less, preferably 480 nm or less, more preferably 460 nm or less. It is desirable to use a light emitter having a wavelength.

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

Among these, as the first light emitter, a GaN LED or LD using a GaN compound semiconductor is preferable. This is because GaN-based LEDs and LDs have significantly higher emission output and external quantum efficiency than SiC-based LEDs that emit light in this region, and emit very bright light with low power when combined with the phosphor. It is because it is 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. As the GaN-based LED and LD, those having an Al _X Ga _Y N light emitting layer, a GaN light emitting layer, or an In _X Ga _Y N light emitting layer are preferable. Among them, since the emission intensity is very high, the GaN-based LED is particularly preferably one having an In _X Ga _Y N light emitting layer, and more preferably a multiple quantum well structure having an In _X Ga _Y N layer and a GaN layer. preferable.

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 an n-type and p-type Al _X Ga _Y N layer, GaN layer, or In _X Those having a heterostructure sandwiched between Ga _Y N layers and the like are preferable because of high light emission efficiency, and those having a heterostructure 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 one or more phosphors of the present invention are used as the first phosphor. A second phosphor (a blue phosphor, a green phosphor, a yellow phosphor, an orange phosphor, a red phosphor, etc.), which will be described later, is contained as appropriate depending on the application. Further, for example, the second light emitter is configured by dispersing the first and second phosphors in a sealing material.

The composition of the phosphor other than the phosphor of the present invention (that is, the second phosphor) used in the second light emitter is not particularly limited, but Y ₂ O ₃ , YVO to be a host crystal. ₄ , Zn ₂ SiO ₄ , Y ₃ Al ₅ O ₁₂ , metal oxides typified by Sr ₂ SiO ₄ , metal nitrides typified by Sr ₂ Si ₅ N ₈ , Ca ₅ (PO ₄ ) ₃ C1 Ce, Pr, Nd, Pm such as phosphates typified by ZnS, SrS, CaS, etc., oxysulfides typified by Y ₂ O ₂ S, La ₂ O ₂ S, etc. , Ions of rare earth metals such as Sm, Eu, Tb, Dy, Ho, Er, Tm, Yb and ions of metals such as Ag, Cu, Au, Al, Mn, Sb, etc. are combined as an activator element or a coactivator element. Can be mentioned.
Specific examples of preferred crystal matrixes are shown in Table 1.

However, the matrix crystal and the activator element or 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 2nd light-emitting body in the light-emitting device of this invention contains the 1st fluorescent substance containing the fluorescent substance of the above-mentioned this invention at least. Any one of the phosphors of the present invention may be used alone, or two or more of them may be used in any combination and ratio, and the phosphor of the present invention may have a desired emission color. What is necessary is just to adjust a composition suitably.

(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. 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. For example, when a green phosphor is used as the first phosphor, a phosphor other than a green phosphor such as a blue phosphor, a red phosphor, or a yellow phosphor may be used as the second phosphor. However, a phosphor having the same color as the first phosphor can be used as the second phosphor.

Second phosphor weight-average median diameter D ₅₀ of which is used for the light emitting device of the present invention is usually 2μm or more and preferably 5μm or more, and usually 30μm or less is preferably in a range of inter alia 20μm or less. When the weight median diameter D ₅₀ is too small, and the luminance decreases tends to phosphor particles tend to agglomerate. On the other hand, if the weight median diameter is too large, there is a tendency for coating unevenness and blockage of the dispenser to occur.

(Blue phosphor)
When a blue phosphor is used in addition to the phosphor of the present invention, any blue phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the blue phosphor is usually 420 nm or more, preferably 430 nm or more, more preferably 440 nm or more, and usually 490 nm or less, preferably 480 nm or less, more preferably 470 nm or less, and further preferably 460 nm or less. It is preferable to be in the wavelength range. When the emission peak wavelength of the blue phosphor used is within this range, it overlaps with the excitation band of the phosphor of the present invention, and the phosphor of the present invention can be efficiently excited by the blue light from the blue phosphor. Because. Table 2 shows phosphors that can be used as such blue phosphors.

Among these, as the blue phosphor, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu, (Ba , Ca, Mg, Sr) ₂ SiO ₄ : Eu, (Ba, Ca, Sr) ₃ MgSi ₂ O 8: Eu are preferred, and (Ba, Sr) MgAl ₁₀ O ₁₇ : Eu, (Ca, Sr, Ba) ₁₀ ( PO ₄ ) ₆ (Cl, F) ₂ : Eu and Ba ₃ MgSi ₂ O ₈ : Eu are more preferable, and Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu and BaMgAl ₁₀ O ₁₇ : Eu are particularly preferable.
(Green phosphor)
When a green phosphor is used in addition to the phosphor of the present invention, any green phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the green phosphor is usually larger than 500 nm, preferably 510 nm or more, more preferably 515 nm or more, and usually 550 nm or less, especially 542 nm or less, and further preferably 535 nm or less. If this emission peak wavelength is too short, it tends to be bluish, while if it is too long, it tends to be yellowish, and the characteristics as green light may deteriorate. Table 3 shows phosphors that can be used as such green phosphors.

Among these, as the green phosphor, Y ₃ (Al, Ga) ₅ O ₁₂ : Tb, CaSc ₂ O ₄ : Ce, Ca ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce, (Sr, Ba) ₂ SiO ₄ : Eu, (Si, Al) ₆ (O, N) ₈ : Eu (β-SiAlON), (Ba, Sr) ₃ Si ₆ O ₁₂ : N ₂ : Eu, SrGa ₂ S ₄ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Mn is preferred.

When the obtained light-emitting device is used for a lighting device, Y ₃ (Al, Ga) ₅ O ₁₂ : Tb, CaSc ₂ O ₄ : CeCa ₃ (Sc, Mg) ₂ Si ₃ O ₁₂ : Ce, (Sr, Ba ) ₂ SiO ₄ : Eu, (Si, Al) ₆ (O, N) ₈ : Eu (β-SiAlON), (Ba, Sr) ₃ Si ₆ O ₁₂ N ₂ : Eu are preferable.
When the obtained light emitting device is used for an image display device, (Sr, Ba) ₂ SiO ₄ : Eu, (Si, Al) ₆ (O, N) ₈ : Eu (β-SiAlON), (Ba, Sr) ₃ Si ₆ O ₁₂ N ₂ : Eu, SrGa ₂ S ₄ : Eu, and BaMgAl ₁₀ O ₁₇ : Eu, Mn are preferable.

(Yellow phosphor)
When a yellow phosphor is used in addition to the phosphor of the present invention, any yellow phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the yellow phosphor is usually in the wavelength range of 530 nm or more, preferably 540 nm or more, more preferably 550 nm or more, and usually 620 nm or less, preferably 600 nm or less, more preferably 580 nm or less. Is preferred. Table 4 shows phosphors that can be used as such yellow phosphors.

More in even, as the yellow _{phosphor, Y 3 Al 5 O 12:} Ce, (Y, Gd) 3 A l5 O 12: Ce, (Sr, Ca, Ba, Mg) 2 SiO 4: Eu, (Ca, Sr) Si ₂ N ₂ O ₂ : Eu is preferred.

(Orange to red phosphor)
When an orange or red phosphor is used in addition to the phosphor of the present invention, any orange or red phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the orange to red phosphor is usually in the wavelength range of 570 nm or more, preferably 580 nm or more, more preferably 585 nm or more, and usually 780 nm or less, preferably 700 nm or less, more preferably 680 nm or less. Is preferred. Table 5 shows phosphors that can be used as such orange to red phosphors.

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, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu, (La, Y) ₂ O ₂ S: Eu, Eu (dibenzoylmethane) ) Β-diketone Eu complex such as 3,1,10-phenanthroline complex, carboxylic acid Eu complex, K ₂ SiF ₆ : Mn is preferred, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Sr, Ca) AlSi (N, O): Eu, (La, Y) ₂ O ₂ S: Eu, and K ₂ SiF ₆ : Mn are more preferable.

As the orange phosphor, (Sr, Ba) ₃ SiO ₅ : Eu, (Sr, Ba) ₂ Si
O ₄ : Eu, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Ce are preferable.
[6. Embodiment of Light Emitting Device]
<Embodiment of Light Emitting Device>
Hereinafter, the light-emitting device of the present invention will be described in more detail with reference to specific embodiments. However, the present invention is not limited to the following embodiments, and does not depart from the gist of the present invention. It can be implemented with arbitrary modifications.

  FIG. 1 is a schematic perspective view showing a positional relationship between a first light emitter serving as an excitation light source and a second light emitter configured as a phosphor containing portion having a phosphor in an example of the light emitting device of the present invention. Shown in In FIG. 1, reference numeral 1 denotes a phosphor-containing portion (second light emitter), reference numeral 2 denotes a surface-emitting GaN-based LD as an excitation light source (first light emitter), and reference numeral 3 denotes a substrate. In order to create a state in which they are in contact with each other, the excitation light source (LD) 2 and the phosphor-containing portion 1 (second light emitter) are separately manufactured, and their surfaces are brought into contact with each other by an adhesive or other means. Alternatively, the phosphor-containing portion 1 (second light emitter) may be formed (molded) on the light emitting surface of the excitation light source (LD) 2. As a result, the excitation light source (LD) 2 and the phosphor-containing part 1 (second light emitter) 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 portion, reference numeral 9 is a conductive wire, and reference numeral 10 is a mold. Each member is indicated.

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

<Applications of light emitting device>
The use of the light-emitting device of the present invention is not particularly limited, and can be used in various fields in which ordinary light-emitting devices are used. However, since the color rendering property is high and the color reproduction range is wide, the illumination device is particularly preferable. And as a light source for image display devices.
(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 cited.

  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 large number of light-emitting devices 13 (on the light-emitting device 4 described above) on the bottom surface of a rectangular holding case 12 whose inner surface is light-opaque such as a white smooth surface. Is provided with a power source and a circuit (not shown) for driving the light-emitting device 13 on the outside, and a milky white acrylic plate or the like is provided at a position corresponding to the lid portion of the holding case 12. The diffusion plate 14 is fixed for uniform light emission.

Then, the surface-emitting illumination device 11 is driven to emit light by applying a voltage to the excitation light source (first light emitter) of the light-emitting device 13, and a part of the light emission is converted to the phosphor-containing portion (first The phosphor in the phosphor-containing resin part as the second phosphor) absorbs and emits visible light, while light emission with high color rendering is obtained by color mixing with blue light or the like not absorbed by the phosphor. The light passes through the diffusion plate 14 and is emitted upward in the drawing, and illumination light with uniform brightness is obtained within the surface of the diffusion plate 14 of the holding case 12.

(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 together 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.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example, unless the summary is exceeded. In addition, the values of various production conditions and evaluation results in the following examples have meanings as preferable values of the upper limit or the lower limit in the embodiment of the present invention, and the preferable range is the value of the upper limit or the lower limit. It may be a range defined by a combination of values of the following examples or values of the examples.

[Measurement and evaluation method of phosphor characteristics]
In Examples 1 to 4 and Comparative Examples 1 and 2 described later, the synthesis and various evaluations of the alloy powder and the phosphor were performed by the following methods.
[Identification of crystal phase of phosphor]
<Powder X-ray diffraction>
The X-ray diffraction intensity of the sample was measured with a powder X-ray diffractometer X′Pert (manufactured by PANalytical). The measurement conditions are as follows. For processing the measurement data, data processing software X'Pert High Score (manufactured by PANalytical) was used.

X-ray source ... CuKα tube X-ray output ... 45 kV, 40 mA
Diverging slit ... 1/4 °, X-ray mirror Detector ... Semiconductor array detector X'Celerator used Ni filter used Scanning range ... 10 ° ≤2θ≤65 °
Reading width: 0.05 °
Counting time… 33s

Crystallography of SrAlSi ₄ N ₇ , Sr ₂ Si ₅ N ₈ , Sr ₂ Al ₂ Si ₁₀ O ₄ N ₁₄ , AlN and Si ₃ N ₄ recorded in Inorganic Crystal Structure Database
Using the Rietan-FP of File and Rietveld analysis program, the powder X-ray diffraction intensities of the above four compounds were calculated, and these diffraction patterns and the powder X-ray diffraction of Examples 1-4 and Comparative Examples 1-2 were calculated. By comparing the pattern, the diffraction peak due to the same crystal structure as SrAlSi ₄ N ₇ , that is, the orthorhombic system and the crystal structure in which the space group is classified as Pna2 ₁ was identified.

[Examples 1-4, Comparative Examples 1-2]
(Manufacture of alloys)
An alloy represented by the composition of Sr ₈ Al ₇ was selected as the raw material compound of the present invention. This alloy was produced in two different atmospheres, N ₂ gas and Ar gas. Hereinafter, an alloy manufactured in an N ₂ atmosphere may be referred to as an “N alloy”, an alloy manufactured in an Ar atmosphere as an “A alloy”, and both may be collectively referred to as an “Sr—Al alloy”.

<N alloy>
Lump metal Sr (manufactured by Aldrich) and lump metal Al were used as raw materials and weighed so that the molar ratio of each metal element was Sr: Al = 8: 7. These metals were put into a boron nitride crucible, heated at 650 ° C. for 1 hour, pulverized, and heated at 700 ° C. for 1 hour to obtain an N alloy. The obtained N alloy was pulverized for 20 minutes using an alumina mortar and pestle so that the particle size was 1 mm or less. The above operation was performed in a glove box filled with N ₂ gas.
The weight of the N alloy increased by 11% before and after heating. Based on this, the contents of Sr element and Al element in the N alloy were estimated to be 91% by weight.
The obtained N alloy was weighed as a phosphor material.

<A alloy>
An A alloy was produced under the same conditions as the N alloy except that it was heated at 700 ° C. for 1 hour in an Ar atmosphere.
The alloy A wetted the side wall of the boron nitride crucible. From the boron nitride crucible containing the A alloy, the boron nitride crucible fixed to the A alloy was removed using a tungsten carbide mortar and pestle and pulverized to a particle size of 1 mm or less. In addition, said operation was performed in the glove box filled with Ar gas.

(Manufacture of phosphors)
As a phosphor raw material, N alloy, A alloy manufactured as described above, Sr ₃ N ₂ (manufactured by Shellac), SrO (manufactured by Aldrich), Si ₃ N ₄ (manufactured by Ube Industries), Al ₂ O ₃ (manufactured by Sumitomo Chemical Co., Ltd.), AlN (manufactured by Tokuyama Co., Ltd.), Eu ₂ O ₃ (manufactured by Shin-Etsu Chemical Co., Ltd.) were used. These raw materials were weighed with an electronic balance so as to have the respective charged composition molar ratios of Examples 1 to 4 and Comparative Examples 1 and 2 shown in Table 6, and pulverized until uniform using an alumina mortar and pestle. And mixed. The weighing of Si ₃ N ₄ , Al ₂ O ₃ , AlN, and Eu ₂ O ₃ was performed in the atmosphere, and the other operations were performed in a glove box filled with N ₂ gas.

From the prepared raw material mixed powder, 1.5 g was weighed and filled into a boron nitride crucible. These boron nitride crucibles were placed in an atmosphere firing electric furnace (manufactured by Hirokisha). Next, the furnace atmosphere was evacuated to 1 × 10 ⁻² Pa or less, and then heated from room temperature to 300 ° C. at a temperature rising rate of 200 ° C./hour. After reaching 300 ° C. and maintaining the temperature for 2 hours, high purity N ₂ gas (99.9995%) was allowed to flow at a pressure of 0.1 MPa at a flow rate of 3 L / min. After 1.5 hours had passed since the introduction of the high purity N ₂ gas, the temperature was raised to 1200 ° C. at a temperature rising rate of 200 ° C./hour. After reaching 1200 ° C., it was heated at a heating rate of 165 ° C./hour until the furnace temperature reached 1450 ° C. and maintained for 8 hours. After firing, the mixture was cooled to 300 ° C. at a temperature drop rate of 224 ° C./hour and then cooled to room temperature. Thereafter, the product was crushed to obtain phosphors of Examples 1 to 4 and Comparative Examples 1 and 2.

For the powder X-ray diffraction patterns of Examples 1 to 4, the diffraction peak attributed to the reflection of the surface index hkl = 221 and 060 of SrAlSi ₄ N _{7 is in} the diffraction angle range of 2θ = 24.5 ° to 25.5 °. Observed. Sr ₂ Al ₃ Si ₇ ON ₁₃ has been reported as a compound having a crystal structure of the same type as SrAlSi ₄ N ₇ (= Sr ₂ Al ₂ Si ₈ N ₁₄ ). In composition formula _{Sr 2 Al 2 Si 8 N 14} , which is a compound obtained by substituting a set of ^Si 4+ ^{-N 3-} pairs in a set of ^Al 3+ ^{-O 2-pairs.} In Examples 1 to 4, Al ₂ O ₃ and Eu ₂ O ₃ were used as starting materials, and further, the raw materials were adjusted so that the molar ratio was Al: Si = 1 + w: 4-w (w = 0.5 or 1). Weighed. Thus, the crystalline phases were attributed to the diffraction peaks of SrAlSi ₄ N ₇ in Example 1-4, SrAlSi ₄ N ₇ containing the O element, i.e. _{(A, Eu) (Si,} Al) 5 (N, O) 7 (However, A represents an alkaline earth metal element in which Sr is essential.) It is considered to be an oxynitride represented by a composition formula.
On the other hand, in the phosphors of Comparative Examples 1 and 2, it was not possible to confirm the presence of a crystal phase considered to be the (A, Eu) (Si, Al) ₅ (N, O) ₇ phase.

According to the present invention, by using an Sr—Al alloy produced with a composition of Sr ₈ Al ₇ as a raw material without using AlN, the stability of the raw material in the atmosphere compared to the conventional phosphor manufacturing method. It can be seen that the (A, Eu) (Si, Al) ₅ (N, O) ₇ phase can be obtained at a low temperature and a low pressure with excellent safety.
This is considered to be mainly due to the low reactivity of AlN at a temperature of 1450 ° C. When AlN was used as a raw material as in Comparative Examples 1 and 2, the obtained crystal phase was a compound having the same crystal structure as Sr ₂ Si ₅ N ₈ . As described above, for Sr ₂ Si ₅ N ₈ , the compound Sr ₂ Si _5−x Al _x N _8−x O _x (wherein the Si ⁴⁺ −N ³⁻ pair is replaced with the Al ³⁺ −O ²⁻ pair) There is a report of x ≦ 0.2), but compared with Sr ₂ Al ₃ Si ₇ ON ₁₃ , the Al content is extremely small with respect to 1 mol of Sr element. Therefore, it is considered that Al was hardly taken into the main crystal phases obtained in Comparative Examples 1 and 2, and remained as AlN without reacting. Therefore, it can be said that the use of an Al-containing compound other than AlN, that is, a Sr—Al alloy in the present invention, as a raw material is one of the solutions for the low-temperature production of the phosphor.
Further, by using an alloy containing Sr and Al, it was possible to obtain a raw material stable in the atmosphere as compared with Sr metal and nitride.

Among Sr—Al based intermetallic compounds, the highest melting point or peritectic temperature is SrAl ₄ , and the melting point is reported to be 1050 ° C. or lower. For this reason, the Sr—Al alloy is superior in that it can be produced at a low temperature as compared with the arc melting method (molten metal temperature = several thousand ° C.) known as a method for producing the phosphor raw material alloy.

  The phosphor of the present invention can be used in any field where light is used. For example, in addition to indoor and outdoor lighting, image display of various electronic devices such as mobile phones, household appliances, and outdoor installation displays. It can be suitably used for an apparatus or the like.

1 Phosphor-containing part (second light emitter)
2 Excitation light source (first light emitter) (LD)
3 Substrate 4 Light-emitting device 5 Mount lead 6 Inner lead 7 Excitation light source (first light emitter)
DESCRIPTION OF SYMBOLS 8 Fluorescent substance containing part 9 Conductive wire 10 Mold member 11 Surface light-emitting illuminating device 12 Holding case 13 Light-emitting device 14 Diffusion plate 22 Excitation light source (1st light-emitting body)
23 Phosphor-containing part (second light emitter)
24 frame 25 conductive wire 26 electrode 27 electrode

Claims (8)

A method for producing a phosphor having a step of firing a phosphor material in a nitrogen-containing atmosphere,
The charged composition of the phosphor material is represented by the following formula [1], and
Firing at a temperature of 1500 ° C. or lower using a compound containing two or more elements other than nitrogen and oxygen among the elements constituting the following formula [1].
The following formula [1]:
(A ^l _1-xl , Z ^l _xl ) _al D ^l _bl E ^l _cl N ^l _dl O ^l _el [1] (In the formula [1], A ^l represents an alkaline earth metal element in which Sr is essential, Z ^l represents one or more activator elements essential to Eu or Ce, D ^l represents a tetravalent metal element essential to Si, and E ^l represents a trivalent metal element essential to Al. Xl represents a number satisfying 0.0001 ≦ xl ≦ 0.20, and al, bl, cl, dl and el are respectively
0.7 ≦ al ≦ 1.3
2.5 ≦ bl ≦ 4.0
1.0 ≦ cl ≦ 3.0
3.5 ≦ (bl + cl) /al≦6.0
0.1 ≦ dl ≦ 7.0
0 <el ≦ 2.0
Indicates the number that satisfies ) 2. The method for producing a phosphor according to claim 1, wherein an alkaline earth metal element and a compound essentially containing Al are used as the compound containing two or more elements constituting the formula [1]. 3. .   A phosphor obtained by the production method according to claim 1 or 2. The phosphor according to claim 3, comprising a crystal phase having a composition represented by the following formula [2].
Following formula [2]:
(A _1-x , Z _x ) _a D _b E _c N _d O _e [2]
(In the formula [2], A represents an alkaline earth metal element essential for Sr, Z represents one or more activator elements essential for Eu or Ce, and D represents Si for essential 4 E represents a trivalent metal element in which Al is essential, x represents a number satisfying 0.0001 ≦ x ≦ 0.20, and a, b, c, d, and e are Each,
0.7 ≦ a ≦ 1.3
2.5 ≦ b ≦ 4.0
1.0 ≦ c ≦ 3.0
3.5 ≦ (b + c) /a≦6.0
5.0 ≦ d ≦ 7.0
0 <e ≦ 2.0
6.5 ≦ (d + e) /a≦7.5
Indicates the number that satisfies )   A phosphor-containing composition, wherein at least one of the phosphors according to claim 3 or 4 is dispersed in a liquid medium. A light emitting device having a first light emitter (excitation light source) and a second light emitter capable of emitting visible light by converting light from the first light emitter,
The second illuminant contains at least one of the phosphors according to claim 3 or claim 4 as the first phosphor, or the fluorescence according to claim 5 as the second illuminant. A light-emitting device comprising the body-containing composition. The light emitting device according to claim 6, wherein the second light emitter contains at least one kind of phosphor having a light emission peak wavelength different from that of the first phosphor as the second phosphor.   An illumination device or an image display device comprising the light-emitting device according to claim 6.

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