JP2014037452A - Fluorescent material and method for manufacturing the same and fluorescent material-containing composition using the fluorescent material - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent material efficiently emitting light when excited by ultraviolet rays having wavelengths corresponding to the vicinity of 300 nm.SOLUTION: The provided fluorescent material has a chemical composition expressed by the following formula (1): MEuMOF(1) (in the formula (1), Mdenotes divalent metal elements indispensably including Ba; Mdenotes trivalent metal elements indispensably including Sc; x, y, z, o, and f are numbers respectively satisfying 0.0001≤x≤0.1, 0.8≤y≤1.2, 0≤z≤1.0, 1.6≤o≤2.4, and 0.8≤f≤1.2).

Description

  The present invention relates to an oxynitride phosphor, a production method thereof, and a phosphor-containing composition using the phosphor.

It is known that ultraviolet rays have different effects on living organisms including humans in the following three wavelength regions.
UV-A (wavelength 315 to 380 nm)
Of those derived from sunlight, 5.6% pass through the atmosphere. Acts on the dermis layer of the skin to denature proteins. It is related to the progression of cellular material alternation and activates cell functions. In addition, the melanin pigment produced by UV-B is oxidized to turn brown (suntan).
UV-B (wavelength 280 to 315 nm)
Of the sources of sunlight, 0.5% passes through the atmosphere. Although acting on the epidermis, pigment cells produce melanin and take a protective response. This is the so-called sunburn.
UV-C (wavelength 200-280nm)
The surface protected by the ozone layer usually does not reach. It has a strong bactericidal action and is the most destructive to living organisms. When the ozone layer is destroyed by global warming and halon-based substances, there is concern that it will reach the earth's surface and significantly affect all biota.
Ultraviolet rays having these wavelengths are contained in sunlight, but recently, ultraviolet rays are artificially generated and used depending on the application. Since these ultraviolet rays are not recognized by human eyes, there is a risk that they may be irradiated unnecessarily and have a serious effect on the living body. Since it is useful for ensuring safety if the range of the irradiated ultraviolet rays can be visually observed, phosphors may be used to convert ultraviolet rays not perceived by human eyes into visible light. It is desired.
On the other hand, perovskite-type oxides have attracted attention as one of the phosphor base materials, and many perovskite-type oxides have already been studied. In recent years, research objects have been expanded to new materials, and oxyfluoride perovskites are being studied as an example. This crystal is synthesized in Non-Patent Document 1.

R. L. Needs, M.M. T.A. Weller J.M. Solid State chemistry 139 422-423 (1998)

Among the phosphors known so far, there has not been known a phosphor that efficiently emits light particularly in the UV-B region. In order to avoid the influence on the living body as described above and ensure safety, it is required to find a phosphor for detecting ultraviolet rays in the UV-B region.
On the other hand, the possibility that it can be used as a phosphor in Non-Patent Document 1 is not suggested, and there is no example in which oxyfluoride perovskite is used as a phosphor.
The present invention has been made in view of such problems, and an object thereof is to provide a phosphor that is excited by ultraviolet rays having a wavelength of about 300 nm and emits light efficiently.

The present inventors examined a series of oxyfluoride-based perovskites from various inorganic compounds having a possibility of becoming a matrix. The present inventors have found that a specific phosphor having an oxyfluoride perovskite as a base crystal and Eu as an activator element is excited by ultraviolet rays having a wavelength of about 300 nm and emits light efficiently, thereby completing the present invention. I let you.
That is, the gist of the present invention is as follows.
[1] A phosphor having a chemical composition represented by the following formula (1).

M ¹ _{1 + z−x} Eu _x M ² _y O _{o + z} F _f (1)
(In the formula (1), M ¹ represents a divalent metal element in which Ba is essential,
M ² represents a trivalent metal element in which Sc is essential,
x, y, z, o, f are respectively
0.0001 ≦ x ≦ 0.1
0.8 ≦ y ≦ 1.2
0 ≦ z ≦ 1.0
1.6 ≦ o ≦ 2.4
It represents a number satisfying 0.8 ≦ f ≦ 1.2. )
In [2] the above formula (1), and the content of Ba in the ^{M 1} is ^{M 1} total 60 mol% or more, the content of Sc in ^{M 2} is at least 70 mol% of the total ^{M 2,} [1 ] The fluorescent substance of description.
[3] In the formula (1), M ¹ is a metal element including Ba alone, or Ba as an essential element and further including one or two selected from the group consisting of Sr, Ca, Mg, and Zn, and M ² The phosphor according to [1] or [2], wherein Sc is a metal element containing only one or two elements selected from the group consisting of Al, Y, Ga, In, and Lu, which is essentially Sc .
[4] The phosphor according to any one of [1] to [3], wherein, in the formula (1), Eu is divalent Eu.
[5] The phosphor according to any one of [1] to [4], which has an emission peak in a wavelength range of 420 nm or more and 530 nm or less.
[6] A method for producing the phosphor according to any one of [1] to [5], comprising a step of firing the phosphor material in a strongly reducing atmosphere. Body manufacturing method. [7] A phosphor-containing composition comprising the phosphor according to any one of [1] to [5] and a liquid medium.

  According to the present invention, it is possible to provide a phosphor that can be excited with ultraviolet light having a wavelength of about 300 nm and emits light efficiently. Thereby, it is possible to detect ultraviolet rays in the UV-B region that may affect the living body as visible light. Moreover, if the phosphor of the present invention is combined with an LED or the like, there is a possibility that a light emitting device having excellent light emission characteristics can be provided.

3 is a chart showing an X-ray diffraction pattern of the phosphor of Example 1. FIG. It is the excitation spectrum and emission spectrum of the phosphor of Example 1. 6 is a chart showing an X-ray diffraction pattern of the phosphor of Example 2. It is the excitation spectrum of the fluorescent substance of Example 1 and 2, and an emission spectrum. 6 is a chart showing an X-ray diffraction pattern of the phosphor of Example 3. It is the excitation spectrum of the fluorescent substance of Example 1 and 3, and an emission spectrum. 6 is a chart showing an X-ray diffraction pattern of the phosphor of Example 4. It is the excitation spectrum and emission spectrum of the phosphors of Examples 1 and 4.

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

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-α Sr _α Al ₂ O ₄ : Eu”, “Sr _1-α Ba _α Al ₂ O ₄ : Eu”, “Ca _1-α Ba _α Al ₂ O ₄ : Eu”, “Ca _1-α-β Sr _α Ba _β Al ₂ O ₄ : Eu” (where 0 <α <1, 0 <β <1, 0 <α + β <1) are all inclusive. It shall be shown in

1. 1. Phosphor 1-1. Composition of phosphor The phosphor of the present invention is a phosphor having oxyfluoride perovskite as a base crystal and Eu as an activator element. It is preferable that at least a part of Eu in the phosphor of the present invention is a divalent ion (Eu ²⁺ ). Specifically, the ratio of Eu ²⁺ in the total Eu is preferably as high as possible, usually 50% or more, preferably 80% or more, more preferably 90% or more, and further preferably 95% or more, and most preferably the following formula ( In 1), Eu is divalent Eu (Eu ²⁺ ).
As a structure of the base crystal, it has a divalent metal element in which Ba is essential, and further has a trivalent metal element in which Sc is essential. The phosphor of the present invention has a composition represented by the following formula (1).

M ¹ _{1 + z−x} Eu _x M ² _y O _{o + z} F _f (1)
(In the formula (1), M ¹ represents a divalent metal element in which Ba is essential,
M ² represents a trivalent metal element in which Sc is essential,
x, y, z, o, f are respectively
0.0001 ≦ x ≦ 0.1
0.8 ≦ y ≦ 1.2
0 ≦ z ≦ 1.0
1.6 ≦ o ≦ 2.4
It represents a number satisfying 0.8 ≦ f ≦ 1.2. )

In the formula (1), M ¹ is a divalent metal element which is essential for Ba. M ¹ may have Ba alone or may contain an element other than Ba. The element contained in M ¹ other than Ba is preferably an alkaline earth metal element, and specifically, one or more metal elements selected from the group consisting of Sr, Ca, Mg, and Zn. It is preferable that Sr is preferable. Therefore, M ¹ is preferably one or more metal elements selected from the group consisting of Sr and Ba, which essentially requires Ba.

The M ¹ overall structure element ratio, the content of Ba is greater than or equal to 60 mol% of the total M ^1, more preferably 65 mol% or more, preferably 70 mol% or more. It is because there exists a tendency for the target fluorescent substance to be obtained, so that there is much content of Ba.
When containing Sr as M ^1, the amount is preferably 40 mol% or less of the total ^{M 1,} and more preferably 30 mol% or less. Moreover, it is preferable to contain 10 mol% or more of Sr in the entire M ¹ because the emission intensity tends to increase. On the other hand, if there is too much Sr, the target phosphor may not be obtained, and light emission may not be desired.

In the formula (1), M ² represents a trivalent metal element in which Sc is essential. Here, M ² may be have a Sc singly, it may contain an element other than Sc. As an element other than Sc, one or more metal elements selected from the group consisting of Al, Y, Ga, In, and Lu are preferable, and Al is more preferable. Therefore, M ² is preferably one or more metal elements selected from the group consisting of Sc and Al, which essentially requires Sc.

The M ² overall structure element ratio, the content of Sc in M ² is preferably at M ² total 70 mol% or more, more preferably 80 mol% or more, is 90 mol% or more More preferably. It is because there exists a tendency for the target fluorescent substance to be obtained, so that there is much content of Sc.
If it contains Al as M ^2, the amount is preferably 30 mol% or less of the total ^{M 2,} and more preferably 10 mol% or less. If there is too much Al, the target phosphor may not be obtained and light may not be emitted.
When Lu is contained as M ² , the amount is preferably 30 mol% or less, more preferably 10 mol% or less of the entire M ² . If there is too much Lu, the target phosphor may not be obtained and light may not be emitted.

In the formula (1), x is a number representing the number of moles of Eu, usually 0.0001 or more, preferably 0.001 or more, more preferably 0.002 or more, and usually 0.1 or less, preferably Is 0.03 or less, more preferably 0.02 or less. Even if the value of x is too small or too large, the emission peak intensity tends to decrease.
In the formula (1), y is a number representing the number of moles of M ² and is usually 0.8 or more, preferably 0.9 or more, more preferably 0.95 or more, and usually 1.2 or less. Preferably it is 1.1 or less, More preferably, it is 1.05 or less. When the phosphor of the present invention consists of a single crystal phase, the value of y is 1.0 in terms of crystallography. However, even when the phosphor of the present invention is composed of a single crystal phase, y may deviate from 1.0 due to the existence of various lattice defects. In such a case, light emission is caused by the lattice defects. Efficiency often decreases. Accordingly, the value of y is preferably close to 1.0, and the light emission efficiency tends to decrease if it is too large or too small.

In the formula (1), 1 + z−x is a number representing the number of moles of M ¹ . Of these, z is preferably 0 or 1.0, more preferably 0. When a large amount of oxygen-containing raw material is used in the manufacturing process of the present phosphor, a large amount of M ¹ may be taken into the phosphor together with oxygen, so that the value of z does not become 0, but an arbitrary value is obtained. Sometimes In such a case, it may be a mixed phase of generated phases having different values of z.

  In the formula (1), o is a number representing the number of moles of O, and the total number of moles of O in the crystal is represented by o + z. o is usually 1.6 or more, preferably 1.85 or more, more preferably 1.925 or more, and usually 2.4 or less, preferably 2.15 or less, more preferably 2.075 or less. If the value of o is too small or too large, the light emission efficiency tends to decrease.

  In the formula (1), f is a number representing the number of moles of F, and is usually 0.8 or more, preferably 0.9 or more, more preferably 0.95 or more, and usually 1.2 or less, preferably Is 1.1 or less, more preferably 1.05 or less. If the value of f is too small or too large, the light emission efficiency tends to decrease.

The phosphor represented by the formula (1) more preferably has a composition represented by the following formula (2).
(Ba, Sr) _1-x Eu _x (Sc, Al) _y O _o F _f (2)
(In the formula (2),
x, y, o, f are respectively
0.0001 ≦ x ≦ 0.1
0.8 ≦ y ≦ 1.2
1.6 ≦ o ≦ 2.4
It represents a number satisfying 0.8 ≦ f ≦ 1.2. )
Specific examples of preferred compositions of the phosphor of the present invention are listed below, but the composition of the phosphor of the present invention is not limited to the following examples.

In the composition formulas representing the following specific examples, Eu is substituted with Ba within a range of 0.01 mol% to 0.1 mol%.
BaScO ₂ F: Eu
Ba ₂ ScO ₃ F: Eu
(Ba _0.8 Sr _0.2 ) ScO ₂ F: Eu
Ba (Sc _0.8 Al _0.2 ) O ₂ F: Eu
(Ba _0.8 Sr _0.2 ) (Sc _0.8 Al _0.2 ) O ₂ F: Eu

1-2. Characteristics of Phosphor The phosphor of the present invention is a phosphor that exhibits light blue emission based on Eu emission.
The phosphor of the present invention can be excited with light having a wavelength in the range of 250 nm to 420 nm. For example, when excited with ultraviolet light having a wavelength of 300 nm, the phosphor has an emission peak in the range of wavelength of 420 nm to 530 nm, It is preferable that the half width of the emission peak is 60 nm or more.
The characteristics of the phosphor of the present invention as described above will be described in detail below.

[Characteristics related to emission spectrum]
The phosphor of the present invention has the following characteristics when an emission spectrum is measured when excited with light having a wavelength of 300 nm, in view of the use as a phosphor for detecting UV in the UV-B region. It is preferable.
<Peak emission wavelength>
First, in the phosphor of the present invention, the peak wavelength λp (nm) in the emission spectrum is usually 420 nm or more, preferably 450 nm or more, and usually 530 nm or less, preferably 520 nm or less, preferably 500 nm or less. A range is more preferable. The peak wavelength λp is preferably adjusted as appropriate according to the application.

<Half width of emission peak>
In addition, the phosphor of the present invention has a full width half maximum of the emission peak in the above-described emission spectrum (hereinafter abbreviated as “FWHM” as appropriate) usually 60 nm or more, particularly 70 nm or more, and usually 120 nm or less. Especially, it is preferable that it is the range of 110 nm or less. If the half-value width FWHM is too narrow, the emission intensity tends to decrease, and if it is too wide, the color purity tends to decrease.

In addition, the measurement of the emission spectrum of the phosphor of the present invention and the calculation of the emission peak wavelength and peak half width are, for example, a 150 W xenon lamp as an excitation light source, and a photomultiplier tube R3788 (Hamamatsu Photonics Co., Ltd.) as a spectrum measurement device. (Manufactured by Shimadzu Corporation).

<Excitation wavelength>
The phosphor of the present invention is preferably excitable with ultraviolet rays in a wavelength range of usually 250 nm or more, particularly 280 nm or more, and usually 350 nm or less, particularly 315 nm or less. Thereby, for example, it becomes possible to detect by converting ultraviolet light centered on the UV-B region into visible light.
The excitation spectrum can be measured at room temperature, for example, 25 ° C., using a fluorescence spectrometer RF-5300PC (manufactured by Shimadzu Corporation). The excitation peak wavelength can be calculated from the obtained excitation spectrum.

<Weight median diameter>
The phosphor of the present invention preferably has a weight median diameter in the range of usually 2 μm or more, especially 5 μm or more, and usually 30 μm or less, especially 20 μm or less. If the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate, which is not preferable. On the other hand, when the weight median diameter is too large, there is a tendency that uneven coating or blockage of a dispenser or the like occurs, which is not preferable.
The weight median diameter of the phosphor of the present invention can be measured using a device such as a laser diffraction / scattering particle size distribution measuring device.

1-3. Method for Producing Phosphor The method for producing the phosphor of the present invention is not particularly limited. For example, in the formula (1), the raw material of the metal element M ¹ (hereinafter referred to as “M ¹ source” as appropriate), the metal element M ^2. The raw material (hereinafter referred to as “M ² source”), the raw material of F (hereinafter referred to as “F source” as appropriate) and the raw material of the element Eu as the activation element (hereinafter referred to as “Eu source” as appropriate) are mixed. It can be manufactured by firing (mixing step) and firing the obtained mixture (firing step).

<Raw material>
Examples of the M ¹ source, the M ² source, the Eu source, and the F source used in the production of the phosphor of the present invention include oxides, hydroxides, carbonates, nitrates of the elements M ¹ , M ^2, and Eu, Sulfates, oxalates, carboxylates, halides and the like can be mentioned. From these compounds, the reactivity to the composite oxide, the low generation amount of NO _x , SO _{x and the} like during firing may be selected as appropriate.

Specific examples of the M ¹ source are listed as follows for each type of M ¹ element.
Specific examples of the Ba source include BaO, Ba (OH) ₂ .8H ₂ O, BaCO ₃ , Ba (NO ₃ ) ₂ , BaSO ₄ , Ba (C ₂ O ₄ ), Ba (OCOCH ₃ ) ₂ , BaF _2. , BaCl ₂ , Ba ₃ N ₂ , BaNH, and the like. Of these, carbonates, oxides, and the like can be preferably used, but carbonates are more preferable from the viewpoint of handling because oxides easily react with moisture in the air. Of these, BaCO ₃ is preferable. This is because the stability in the air is good, and since it is easily decomposed by heating, undesired elements hardly remain and it is easy to obtain a high-purity raw material. In addition, when using carbonate as a raw material, it is preferable to pre-fire and use carbonate as a raw material. On the other hand, BaF ₂ is preferable from the viewpoint of efficiency because it can be used as an F source.
Specific examples of the Sr source include SrO, Sr (OH) ₂ .8H ₂ O, SrCO ₃ , Sr (NO ₃ ) ₂ , SrSO ₄ , Sr (C ₂ O ₄ ) · H ₂ O, Sr (OCOCH ₃ ). _{2 · 0.5H 2 O, SrCl 2} , SrF 2, Sr 3 N 2, SrNH and the like. Among these, SrCO ₃ is preferable. This is because the stability in the air is good, it is easily decomposed by heating, it is difficult for undesired elements to remain, and it is easy to obtain high-purity raw materials. In addition, when using carbonate as a raw material, it is preferable to pre-fire and use carbonate as a raw material.

Specific examples of the Ca source include CaO, Ca (OH) ₂ , CaCO ₃ , Ca (NO ₃ ) ₂ .4H ₂ O, CaSO ₄ .2H ₂ O, Ca (C ₂ O ₄ ) · H ₂ O, and Ca. _{(OCOCH 3) 2 · H 2} O, CaCl 2, CaF 2, Ca 3 N 2, CaNH and the like. Of these, CaCO ₃ and CaCl ₂ are preferable.
Specific examples of the Mg source include MgO, Mg (OH) ₂ , MgCO ₃ , Mg (NO ₃ ) ₂ .6H ₂ O, MgSO ₄ .7H ₂ O, Mg (C ₂ O ₄ ) · 2H ₂ O, Mg (OCOCH ₃ ) ₂ .4H ₂ O, MgCl ₂ , MgF ₂ , Mg ₃ N ₂ , MgNH and the like can be mentioned. Of these, MgO, MgCO ₃ , and MgCl ₂ are preferable.

Specific examples of the Zn source include zinc compounds such as ZnO, ZnF ₂ , ZnCl ₂ , Zn (OH) ₂ , Zn ₃ N ₂ , ZnNH (but may be hydrates). Of these, ZnF ₂ .4H ₂ O (however, it may be an anhydride) is preferable from the viewpoint that the effect of promoting particle growth is high. ZnF ₂ may be used as a flux.
Specific examples of the Eu source include Eu ₂ O ₃ , Eu ₂ (SO ₄ ) ₃ , Eu ₂ (OCO) ₆ , EuCl ₂ , EuCl ₃ , EuF ₃ , Eu (NO ₃ ) ₃ .6H ₂ O, and the like. It is done. Of these, Eu ₂ O ₃ , Eu (NO ₃ ) ₃ .6H ₂ O, and EuCl ₂ are preferable. On the other hand, EuF ₃ is preferable from the aspect of efficiency because it can be used as an F source.

Specific examples of M ² source, when listed separately for each type of M ² element is as follows.
Examples of the Sc source compound include Sc ₂ O ₃ , Sc (OH) ₃ , Sc ₂ (CO ₃ ) ₃ , Sc (NO ₃ ) ₃ , Sc ₂ (SO ₄ ) ₃ , Sc ₂ (OCO) ₆ , Sc (OCOCH) ₃ ) ₃ , ScCl ₃ , ScF _{3 and the} like. Among these, Sc ₂ O ₃ is preferable because it is easily available and a high-purity product is highly likely to be obtained.

Examples of the Al source compound include Al ₂ O ₃ , Al (OH) ₃ , AlOOH, Al (NO ₃ ) ₃ .9H ₂ O, Al ₂ (SO ₄ ) ₃ , AlCl ₃ , and AlF ₃ . Among these, Al ₂ O ₃ is preferable because it is easily available and high possibility of obtaining a high-purity product.
As specific examples of trivalent metals other than Sc and Al, Y source compounds include Y ₂ O ₃ , Y (OH) ₃ , Y ₂ (CO ₃ ) ₃ , Y (NO ₃ ) ₃ , Y ₂ ( SO ₄ ) 3, Y ₂ (OCO) ₆ , Y (OCOCH ₃ ) ₃ , YCl _{3 and the} like, and examples of the Lu source compound include Lu ₂ O ₃ , Lu ₂ (SO ₄ ) ₃ and LuCl _3. It is done. Among them, Lu ₂ O ₃ is preferable because it is easily available and a high-purity product is highly likely to be obtained.

Examples of the Ga source compound include Ga ₂ O ₃ , Ga (OH) ₃ , GaOOH, Ga (NO ₃ ) ₃ .3H ₂ O, Ga ₂ (SO ₄ ) ₃ , and GaCl ₃ . Among them, Ga ₂ O ₃ is preferable because it is easily available and a high-purity product is highly likely to be obtained.
Incidentally, M ¹ source described above, M ² source and Eu source, respectively, may be used alone, or as a combination of two or more kinds in any combination and in any ratio. It is more preferable to use a coprecipitation raw material in which elements as raw material components are mixed at an atomic level.
As F source, it is convenient to use BaF ₂ because Ba is essential for the phosphor. Moreover, SrF ₂ can also be used for Sr solid solution. Moreover, since Sc is essential, ScF3 can also be used. AlF ₃ can also be used for Al solid solution.

<Mixing process>
The method for mixing the M ¹ source, the M ² source, the Eu source and the F source is not particularly limited, but examples include the following methods (A) and (B).
(A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., or pulverization using mortar and pestle, etc., and mixer such as ribbon blender, V-type blender, Henschel mixer, etc., or mortar and pestle are used. A dry mixing method in which raw materials such as M ¹ source, M ² source, and Eu source are pulverized and mixed in combination with mixing.
(B) A solvent or dispersion medium such as water is added to raw materials such as M ¹ source, M ² source, Eu source and F source, and mixed using a pulverizer, mortar and pestle, or evaporating dish and stirring rod, A wet mixing method in which a solution or slurry is made and then dried by spray drying, heat drying, or natural drying.

<Baking process>
(Baking conditions)
The firing step is usually a mixture of raw materials such as M ¹ source, M ² source, Eu source and F source obtained by the above-mentioned mixing step, and a heat-resistant container such as a crucible or a tray made of a material having low reactivity with each raw material. Put in and heat.
As the material of the heat-resistant container used at the time of firing, ceramics such as alumina, quartz, boron nitride, silicon carbide, silicon nitride, magnesium oxide, metals such as platinum, molybdenum, tungsten, tantalum, niobium, iridium, rhodium, or the like An alloy containing carbon as a main component, carbon (graphite) and the like can be given. Here, when selected from the viewpoint of cost and availability, a heat-resistant container made of alumina is preferable, and when selected from the viewpoint of low reactivity with each raw material, a heat-resistant container made of platinum or molybdenum is used. preferable.

In addition, the filling rate when filling the phosphor raw material into the heat-resistant container may vary depending on the firing conditions, but it may be filled to such an extent that the fired product is not easily pulverized in the post-processing step, usually 10% by volume or more, Usually 90% by volume or less.
Further, when it is desired to increase the amount of the phosphor raw material to be processed at a time, it is preferable that heat is uniformly circulated in the heat-resistant container, for example, by decreasing the rate of temperature rise.
Moreover, it is preferable that the filling rate at the time of filling the heat-resistant container in the furnace is such that the heat does not become uneven between the heat-resistant containers in the furnace.
Furthermore, in the above baking, when the number of heat-resistant containers in the baking furnace is large, for example, to make the heat transfer to each heat-resistant container uniform, such as slowing the temperature increase rate, It is preferable for firing without unevenness.

In the temperature raising process at the time of firing, it is preferable that a part of the temperature is reduced. Specifically, at any time when the temperature is preferably room temperature or higher, and preferably 1500 ° C. or lower, more preferably 1200 ° C. or lower, and even more preferably 1000 ° C. or lower, the reduced pressure state (specific In general, it is preferably in the range of 10 ⁻² Pa to less than 0.1 MPa. Among them, it is preferable to introduce an inert gas or a reducing gas, which will be described later, into the system after reducing the pressure in the system, and to raise the temperature in that state.
At this time, if necessary, it may be maintained at the target temperature for usually 1 minute or longer, preferably 5 minutes or longer, more preferably 10 minutes or longer. The holding time is usually 5 hours or less, preferably 3 hours or less, more preferably 1 hour or less.

The temperature during firing (maximum temperature reached) is usually 900 ° C. or higher, preferably 1000 ° C. or higher, and usually 1500 ° C. or lower, preferably 1200 ° C. or lower. If the firing temperature is too low, crystals do not grow sufficiently and the particle size tends to be small. On the other hand, if the firing temperature is too high, the crystal tends to grow too much and the particle size tends to increase, and the phosphor raw material is likely to react with the aforementioned heat-resistant container, or the heat-resistant container itself is altered by heat, There is also the possibility of deformation.
The rate of temperature rise is usually 1 ° C./min or more, preferably 3 ° C./min or more, and usually 20 ° C./min or less, preferably 10 ° C./min or less. Below this range, the firing time may be longer. Moreover, when it exceeds this range, a baking apparatus, a container, etc. may be damaged.
The pressure at the time of firing is not particularly limited because it varies depending on the firing temperature or the like, but is usually 0.01 MPa or more, preferably 0.1 MPa or more, and usually 200 MPa or less, preferably 100 MPa or less. Among these, industrially, it is usually about atmospheric pressure to about 0.3 MPa, and atmospheric pressure is preferable in terms of cost and labor.

The firing time varies depending on the temperature and pressure during firing, but is usually in the range of 10 minutes or longer, usually 24 hours or shorter, preferably 1 hour or longer, and preferably 6 hours or shorter.
In the phosphor of the present invention, it is preferable that Eu is present as a divalent Eu ion. Therefore, when a compound having trivalent Eu is used as the Eu source, a reducing atmosphere is used. It is necessary to.
As a specific example, it is carried out in an atmosphere of any one of gases such as carbon monoxide, carbon dioxide, nitrogen, hydrogen, and argon, or in a mixed atmosphere of two or more. Among these, it is preferable to contain reducing gas, such as carbon monoxide and hydrogen, and especially under a nitrogen atmosphere containing hydrogen.

Here, the hydrogen content contained in the hydrogen-containing nitrogen atmosphere is usually 1% by volume or more, preferably 2% by volume or more, and usually 5% by volume or less, and the most preferable hydrogen content is 4% by volume. . If the hydrogen content in the atmosphere is too high, the safety may decrease, and if it is too low, a sufficient reducing atmosphere cannot be achieved.
Furthermore, in the present invention, as a method of reducing trivalent Eu ions to bivalent during firing, the firing atmosphere is a reducing atmosphere such as a hydrogen-containing nitrogen atmosphere, and solid carbon is also present in the reaction system. Therefore, it is preferable to reduce the oxygen concentration to a strong reducing atmosphere.
That is, in general, a small amount of air may enter the baking apparatus, but by coexisting solid carbon, the influence is reduced and the phosphor of the present invention is stably produced. be able to.

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

The amount of solid carbon to be coexisted is usually 0 with respect to the produced phosphor from the viewpoint of the balance between the properties of the phosphor and the productivity, although it depends on the amount of the phosphor raw material to be treated at one time and other firing conditions. .1% by weight or more, preferably 1% by weight or more, more preferably 10% by weight or more, and further preferably 15% by weight or more.
Further, by using a graphite crucible as a firing container, it is possible to obtain the same effect as the coexistence of solid carbon. On the other hand, when a crucible made of a material other than carbon such as an alumina crucible is used, it is preferable that solid carbon such as graphite and activated carbon coexist separately. The shape of the solid carbon is not particularly limited, and examples thereof include a bead shape, a granular shape, and a block shape. In addition, it is preferable to perform baking under sealed conditions, such as covering the crucible.
Here, “calcining in the presence of solid carbon” means that the phosphor raw material and the solid carbon are present in the same baking container. In this case, in particular, the phosphor raw material and the solid carbon Are preferably arranged close to each other.

As a method of placing solid carbon close to the phosphor raw material, the solid carbon is put in a container different from the container containing the phosphor raw material, and these containers are installed in the same crucible (for example, the raw material container A solid carbon container is placed in the upper part); a container containing solid carbon is embedded in the phosphor material; or, conversely, the solid carbon is disposed around the container filled with the phosphor material powder; The method is specifically mentioned. When a large crucible is used, it is preferable to take a method in which a container containing solid carbon is placed in the same container as the phosphor raw material and fired. In any case, it is preferable to devise so that solid carbon is not mixed in the phosphor material.

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

  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.

(material)
As a raw material compound of the phosphor, BaCO ₃ (manufactured by Kanto Chemical, purity 99.9%), SrCO ₃ (manufactured by Kanto Chemical, purity 99.9%), BaF ₂ (manufactured by high purity chemical, 99.9%), SrF ₂ (manufactured by high purity chemical, 99.9%), Sc ₂ O ₃ (manufactured by Shin-Etsu Chemical, purity 99.99%), Al ₂ O ₃ (manufactured by Furuuchi Chemical, purity 99.99%), EuF ₃ (high Purity Chemical, 99.9%) were used.

(X-ray diffraction pattern analysis)
About the obtained fluorescent substance, the powder X-ray pattern analysis was performed with the following method. Powder X-ray diffraction was precisely measured with a powder X-ray diffractometer RINT-2000 (manufactured by Rigaku Corporation). The measurement conditions are as follows.

・ Uses CuKα tube
・ X-ray output 40KV 40mA
・ Divergent slit 1 °
・ Detector scintillation counter ・ Scanning range 2θ = 10 ° ～ 90 °
・ Reading width 0.02 °
・ Counting time 0.5 seconds
About the obtained pattern, it compared and identified using the following reference patterns, respectively.

BaScO ₂ F: (ICSD150171)
Sc ₂ O _3: (JCPDS42-1463)
BaF _2: (JCPDS04-0452)
(Emission spectrum, excitation spectrum)
About the obtained phosphor, using a fluorescence spectrophotometer RF-5300PC (manufactured by Shimadzu Corporation) equipped with a 150 W xenon lamp as an excitation light source and a photomultiplier tube R3788 (manufactured by Hamamatsu Photonics) as a spectrum measuring device, The emission peak intensity in the wavelength range of 400 to 700 nm was measured.

Specifically, the light from the excitation light source was passed through the diffraction grating spectrometer, and only the excitation light having a wavelength of 300 nm was irradiated onto the phosphor. The light generated from the phosphor by irradiation of excitation light is dispersed by a diffraction grating spectrometer, the emission intensity of each wavelength is measured by a spectrum measuring device in the wavelength range of 400 nm to 700 nm, and signal processing such as sensitivity correction by a personal computer. After that, an emission spectrum was obtained. During the measurement, the slit width of the light receiving side spectroscope was set to 1.5 nm.
The excitation spectrum was measured at room temperature (25 ° C.) using a fluorescence spectrometer RF-5300PC (manufactured by Shimadzu Corporation) equipped with a photomultiplier tube R214 (manufactured by Hamamatsu Photonics). More specifically, a blue emission peak at 475 to 485 nm was monitored to obtain an excitation spectrum within a wavelength range of 250 nm to 440 nm.

<Example 1>
The phosphor was synthesized as follows.
The raw materials were weighed as shown in Table 2 so that the composition of the obtained phosphor had the molar ratio shown in Table 1. The weighed raw material compounds were mixed and stirred in ethanol for 20 minutes using an agate pestle and an agate mortar, and then dried at 50 ° C. for 1 hour. Then, using a pressure press machine (MT-20H manufactured by NPa System Co., Ltd.) and a WC forming device, a pressure of 5 MPa was applied and the mixed powder was 10 mm.
It was formed into φ disk-shaped pellets. The pellet was transferred to an alumina crucible (purity 99.6%), covered, and then inserted into a large alumina crucible filled with activated carbon (Kanto Chemical). Alumina crucible in a tubular furnace (Morishiri horizontal electric furnace HF-1700 manufactured by Crystal System Co., Ltd.)
). A reducing gas of 0.1 liter / min was allowed to flow there. As the reducing gas, a mixed gas of 2% hydrogen and 98% nitrogen was used. The temperature was raised from 20 ° C. to 1100 ° C. at 2.5 ° C./min. Thereafter, it was maintained at 1100 ° C. (maximum temperature reached) under normal pressure for 3 hours. Cooling was performed from 1100 ° C. to 20 ° C. at 2.5 ° C./min, and the sintered pellets were taken out from the crucible. The taken-out pellet was pulverized with an agate pestle and an agate mortar to obtain a phosphor.

The X-ray diffraction pattern of the obtained phosphor is shown in FIG. 1, and the excitation spectrum and emission spectrum are shown in FIG. It can be seen from FIG. 1 that BaScO ₂ F is generated as the main component. Further, FIG. 2 shows that it absorbs ultraviolet light of 315 nm or less and emits fluorescence having a peak at 475 nm.

<Example 2>
The phosphor was synthesized as follows.
A phosphor was obtained in the same manner as in Example 1 except that the raw materials were weighed as shown in Table 2 so that the composition of the obtained phosphor had the molar ratio shown in Table 1.
The X-ray diffraction pattern of the obtained phosphor is shown in FIG. 3, and the excitation spectrum and emission spectrum are shown in FIG. FIG. 3 shows that BaScO ₂ F is generated as the main component. In addition, it can be seen from FIG. 4 that the emission intensity increases as the Eu concentration increases compared to the phosphor of Example 1.

<Example 3>
The phosphor was synthesized as follows.
A phosphor was obtained in the same manner as in Example 1 except that the raw materials were weighed as shown in Table 2 so that the composition of the obtained phosphor had the molar ratio shown in Table 1.
An X-ray diffraction pattern of the obtained phosphor is shown in FIG. 5, and an excitation spectrum and an emission spectrum are shown in FIG. It can be seen from FIG. 5 that a BaScO ₂ F similar phase is generated as the main component. The main peak of diffraction is shifted by a high angle because of the effect of Sr substitution. From FIG. 6, it can be seen that by replacing part of the Ba position with Sr, the emission wavelength is longer than that of Example 1, the emission intensity is increased, and the excitation band is also longer.

<Example 4>
The phosphor was synthesized as follows.
A phosphor was obtained in the same manner as in Example 1 except that the raw materials were weighed as shown in Table 2 so that the composition of the obtained phosphor had the molar ratio shown in Table 1.
An X-ray diffraction pattern of the obtained phosphor is shown in FIG. 7, and an excitation spectrum and an emission spectrum are shown in FIG. It can be seen from FIG. 7 that a BaScO ₂ F similar phase is generated as the main component. It is the effect of Sr substitution and Al substitution that the main peak of diffraction is shifted at a high angle. From FIG. 8, by replacing part of the Ba position with Sr and substituting part of the Sc position with Al, the emission intensity is comparable to that of Example 1, but the emission wavelength becomes longer. .

  The phosphor of the present invention is useful for detecting ultraviolet rays having a wavelength of around 300 nm. Further, the present invention is not limited to this application, and can be used in any field where light is used, and can be suitably used for white LEDs, fluorescent lamps, PDPs, CRTs, ELs, and the like.

Claims (7)

A phosphor having a chemical composition represented by the following formula (1):
M ¹ _{1 + z−x} Eu _x M ² _y O _{o + z} F _f (1)
(In the formula (1), M ¹ represents a divalent metal element in which Ba is essential,
M ² represents a trivalent metal element in which Sc is essential,
x, y, z, o, f are respectively
0.0001 ≦ x ≦ 0.1
0.8 ≦ y ≦ 1.2
0 ≦ z ≦ 1.0
1.6 ≦ o ≦ 2.4
It represents a number satisfying 0.8 ≦ f ≦ 1.2. ) In the formula (1), and the content of Ba in the ^{M 1} is ^{M 1} total 60 mol% or more, the content of Sc in ^{M 2} is at least 70 mol% of the total ^{M 2,} claim 1 Phosphor. In the formula (1),
M ¹ is a metal element including Ba alone, or Ba as an essential element and further including one or two selected from the group consisting of Sr, Ca, Mg, and Zn,
^3. The phosphor according to claim 1, wherein M ² is only Sc, or a metal element including Sc as an essential element and further including one or two selected from the group consisting of Al, Y, Ga, In, and Lu. .   The phosphor according to any one of claims 1 to 3, wherein Eu in the formula (1) is divalent Eu.   The phosphor according to any one of claims 1 to 4, which has an emission peak in a wavelength range of 420 nm or more and 530 nm or less.   A method for producing the phosphor according to any one of claims 1 to 5, comprising a step of firing the phosphor material in a strongly reducing atmosphere.   A phosphor-containing composition comprising the phosphor according to any one of claims 1 to 5 and a liquid medium.

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