JP5332136B2 - Nitrogen-containing alloy and phosphor manufacturing method using the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for manufacturing a phosphor of high characteristics, especially of high intensity industrially, and to provide a nitrogen-containing alloy for use in the method for manufacturing the phosphor. <P>SOLUTION: This method comprises a step of heating a phosphor material under a nitrogen-containing atmosphere, wherein an alloy which contains two or more metal elements constituting the phosphor is used as all or a part of the phosphor, and the heating step is carried out within a temperature variation of 50&deg;C per minute. Because the method permits to control rapid nitrization at the heating step, the phosphor of high characteristics, especially of high intensity can be manufactured industrially. <P>COPYRIGHT: (C)2008,JPO&amp;INPIT

Description

  The present invention relates to a nitrogen-containing alloy as a raw material for producing a phosphor based on nitride or oxynitride, and a method for producing a phosphor based on a nitride or oxynitride based on this nitrogen-containing alloy. .

  Phosphors are used in fluorescent lamps, fluorescent display tubes (VFD), field emission displays (FED), plasma display panels (PDP), cathode ray tubes (CRT), white light emitting diodes (LEDs) and the like. In any of these applications, in order to make the phosphor emit light, it is necessary to supply the phosphor with energy for exciting the phosphor, and the phosphor is not limited to vacuum ultraviolet rays, ultraviolet rays, visible rays, electron beams, etc. When excited by an excitation source having high energy, it emits ultraviolet rays, visible rays, and infrared rays. However, when the phosphor is exposed to the excitation source as described above for a long time, there is a problem that the luminance of the phosphor decreases.

  Therefore, in recent years, ternary systems have been used in place of conventional phosphors such as silicate phosphors, phosphate phosphors, aluminate phosphors, borate phosphors, sulfide phosphors, and oxysulfide phosphors. Many new materials have been synthesized for the above nitrides. In recent years, phosphors having excellent characteristics have been developed particularly in multi-component nitrides and oxynitrides based on silicon nitride.

In Patent Document 1, the general formula M _x Si _y N _z : Eu [where M is at least one alkaline earth metal element selected from the group consisting of Ca, Sr, and Ba, and x, y , And z are numbers satisfying z = 2 / 3x + 4 / 3y. ] Are disclosed. These phosphors are synthesized by adding alkaline earth metal nitride by nitriding alkaline earth metal and adding silicon nitride to this, or using an alkaline earth metal and silicon imide as raw materials. It is synthesized by heating in a nitrogen or argon stream. In both cases, alkaline earth metal nitrides sensitive to air and moisture had to be used as raw materials, and there was a problem in industrial production.

Further, in Patent Document 2, an oxynitride represented by a general formula M ₁₆ Si ₁₅ O ₆ N ₃₂ : Eu, a general formula MSiAl ₂ O ₃ N ₂ : Eu, M ₁₃ Si ₁₈ Al ₁₂ O ₁₈ N ₃₆ : Eu, MSi An oxynitride phosphor having a sialon structure represented by ₅ Al ₂ ON ₉ : Eu and M ₃ Si ₅ AlON ₁₀ : Eu is disclosed. In particular, when M is Sr, SrCO ₃ , AlN, and Si ₃ N ₄ are mixed at a ratio of 1: 2: 1 and heated in a reducing atmosphere (hydrogen-containing nitrogen atmosphere). As a result, SrSiAl ₂ O ₃ N ₂ : It is described that Eu ²⁺ was obtained.
In this case, the obtained phosphor is only an oxynitride phosphor, and no nitride phosphor containing no oxygen is obtained.

  In addition, since the nitride or oxynitride phosphor has a low reactivity of the raw material powder used, the contact area between the raw material powders for the purpose of promoting a solid-phase reaction between the raw material mixed powders during firing. It is necessary to heat with increasing the size. Therefore, these phosphors are synthesized in a compression molded state at a high temperature, that is, a very hard sintered body. Therefore, the sintered body obtained in this way needs to be pulverized to a fine powder suitable for the intended use of the phosphor. However, when a phosphor that is a hard sintered body is pulverized over a long period of time using a normal mechanical pulverization method such as a jaw crusher or a ball mill, There has been a problem that a large number of defects are generated and the emission intensity of the phosphor is significantly reduced.

In addition, it is said that alkaline earth metal nitrides such as calcium nitride (Ca ₃ N ₂ ) and strontium nitride (Sr ₃ N ₂ ) are preferably used in the production of nitride or oxynitride phosphors. In general, divalent metal nitrides easily react with moisture to form hydroxides, and are unstable in moisture-containing atmospheres. In particular, in the case of powder of Sr ₃ N ₂ or Sr metal, this tendency is remarkable and handling is very difficult.

  For these reasons, new phosphor materials and methods for producing the same have been demanded.

  In recent years, Patent Document 3 has been reported regarding a method for producing a nitride phosphor using a metal as a starting material. Patent Document 3 discloses an example of a method for producing an aluminum nitride phosphor, which describes that transition elements, rare earth elements, aluminum and alloys thereof can be used as raw materials. However, an example using an alloy as a raw material is not described, and it is characterized by using Al metal as an Al source. In addition, it differs from the present invention in that a combustion synthesis method is used to ignite the raw material and instantaneously raise the temperature to a high temperature (3000 K). That is, it is difficult to uniformly distribute the activation element by the method of instantaneously raising the temperature to 3000 K, and it is difficult to obtain a phosphor having high characteristics. Further, there is no description regarding a nitride phosphor containing an alkaline earth metal element obtained from an alloy raw material, and further a nitride phosphor containing silicon.

Accordingly, some inventors of the present invention invented a method for producing a phosphor by heating an alloy containing two or more metal elements constituting the phosphor in a nitrogen-containing atmosphere, and previously filed a patent application. (Patent Document 4).
Special table 2003-515665 gazette JP 2003-206481 A JP 2005-54182 A Japanese Patent Application No. 2006-086850

  As a result of studies by the present inventors, in the case of producing a phosphor based on a nitride or oxynitride based on an alloy as a raw material, the nitriding reaction proceeds rapidly during heating, and the generated heat causes melting or phase separation of the raw material. It has also been found that the decomposition of nitride may occur and the characteristics of the phosphor may deteriorate. In particular, it has been found that if a large amount of raw material is heat-treated at once or the packing density of the raw material is increased in order to increase productivity, the phosphor may not be obtained in some cases.

The present invention has been made in view of the above-described problems, and an object thereof is to provide a method for manufacturing a phosphor capable of industrially producing a phosphor having high characteristics, particularly high brightness. . Another object of the present invention is to provide a phosphor obtained by the method for producing the phosphor, a phosphor-containing composition and a light-emitting device using the phosphor, and an image display device and an illumination device using the light-emitting device. Is to provide.
Another object of the present invention is to provide a nitrogen-containing alloy that can be used in the method for producing the phosphor.

  In light of the above-mentioned problems, the present inventors have intensively studied a method for producing a phosphor, and as a result, an alloy containing two or more metal elements constituting the phosphor as a whole or a part of the raw material (hereinafter referred to as “fluorescence”). In the process of heating the phosphor material, when the temperature change during the heat treatment is controlled to be within a certain range, the phosphor is heated at one time. We have found that we can increase the amount we can.

That is, the gist of the present invention is the following (1) to ( 8 ).

(1) A method for producing a nitride or oxynitride phosphor comprising a step of heating a phosphor material in a nitrogen-containing atmosphere, wherein a metal element constituting the phosphor is used as part or all of the phosphor material. An alloy having two or more kinds (hereinafter referred to as “phosphor raw material alloy”) is used, and in the heating step, from a temperature 100 ° C. lower than the melting point of the phosphor raw material alloy to a temperature lower than the melting point by 30 ° C. A method for producing a phosphor, which is heated under the condition that the temperature change per minute in the temperature range is within 50 ° C. and satisfies the following 1).
1) A part or all of the phosphor raw material alloy is a nitrogen-containing alloy having a total metal element content of 97% by weight or less and a nitrogen content of 0.8% by weight or more and 27% by weight or less.

(2) The phosphor is a phosphor represented by the following general formula [1], and in the following general formula [1], M ¹ is Cr, Mn, Fe, Ce, Pr, Nd, Sm, Eu. , Tb, Dy, Ho, Er , at least one element selected from the group consisting of Tm, and Yb, ^{M 2} is Mg, Ca, Sr, Ba, and from the group consisting of Zn 1 or more selected An element, M ³ is one or more elements selected from the group consisting of Al, Ga, In, and Sc, and M ⁴ is selected from the group consisting of Si, Ge, Sn, Ti, Zr, and Hf The method for producing a phosphor according to (1), which is one or more elements .
_{^{M 1 a M 2 b M 3}} c M 4 d N e O f [1]
(However, a, b, c, d, e, and f are values in the following ranges, respectively.
0.00001 ≦ a ≦ 0.15
a + b = 1
0.5 ≦ c ≦ 1.5
0.5 ≦ d ≦ 1.5
2.5 ≦ e ≦ 3.5
0 ≦ f ≦ 0.5 )

(3) The method for producing a phosphor according to (1) or (2), wherein any one of the following 2) to 4) is satisfied.
2) The rate of temperature increase in the temperature range from a temperature lower than the melting point of the phosphor raw material alloy by 100 ° C. to a temperature lower than the melting point by 30 ° C. is 9 ° C./min or less. 3) As the phosphor raw material, the phosphor A nitride or oxynitride containing one or more metal elements constituting the phosphor is used together with the raw material alloy. 4) The phosphor having an angle of repose of 45 degrees or less as the phosphor raw material alloy. Use alloy powder for raw materials

(4) In the heating step, the phosphor material is heated in a firing container, and the ratio of the weight of the phosphor material to the weight of the firing container represented by the following formula [A] is 0.1. It is the above, The manufacturing method of the fluorescent substance in any one of (1) thru | or (3) characterized by the above-mentioned.
(Mass of phosphor material) / {(Mass of firing container) + (Mass of phosphor material)} [A]

( 5 ) The method for producing a phosphor according to any one of (1) to ( 4 ), wherein the nitrogen-containing alloy satisfies the following formula [7].
0.03 ≦ NI / NP ≦ 0.9 [7]
(In Formula [7],
NI represents the nitrogen content (% by weight) of the nitrogen-containing alloy,
NP represents the nitrogen content (% by weight) of the phosphor to be produced. )

( 6 ) The step of heating the nitrogen-containing alloy as part or all of the phosphor raw material in a nitrogen-containing atmosphere (hereinafter referred to as “secondary nitriding step”) is 300 ° C. or higher than the melting point of the nitrogen-containing alloy. The method for producing a phosphor according to any one of (1) to ( 5 ), wherein the phosphor is a step of heating at a high temperature.

(7) Prior to the secondary nitriding process, in any one of (1), characterized by comprising the step of cooling said nitrogen-containing alloy to a temperature lower 100 ° C. or higher than the melting point of the nitrogen-containing alloy (6) The manufacturing method of fluorescent substance of description.

( 8 ) The method for producing a phosphor according to any one of (1) to ( 7 ), including a step of pulverizing the nitrogen-containing alloy prior to the secondary nitriding step.

According to the present invention, it is possible to suppress the rapid progress of the nitriding reaction in the heating step when manufacturing the phosphor using the phosphor raw material alloy as a part or the whole of the raw material, and thus high characteristics, particularly A high-luminance phosphor can be industrially produced.
Further, according to the present invention, it is possible to provide a nitrogen-containing alloy that is excellent as a phosphor raw material.

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 this specification, an alloy includes a solid solution of two or more metals, a eutectic, an intermetallic compound, and a material in which these coexist, and may include a nonmetallic element.

[Phosphor production method]
The phosphor production method of the present invention (hereinafter sometimes simply referred to as “the production method of the present invention”) is a phosphor production method including a step of heating a phosphor material in a nitrogen-containing atmosphere. As a part or all of the phosphor raw material, an alloy having two or more metal elements constituting the phosphor (hereinafter referred to as “phosphor raw material alloy”) is used.

  Since the nitriding reaction is an exothermic reaction, if a large amount of phosphor raw material is nitrided by heating at a time in the heating step, a runaway reaction accompanied by a sudden exotherm occurs. In some cases, a part of the material is volatilized or particles of the phosphor raw material alloy are often fused with each other, so that the emission characteristics of the obtained phosphor may be deteriorated or the phosphor may not be obtained. Therefore, as in the production method of the present invention, adjusting the temperature change range in the heating step can suppress the rapid progress of the nitriding reaction even if the amount of the phosphor raw material to be processed at once is increased. It is possible to industrially produce a simple phosphor.

  In the production method of the present invention, in the heating step, the temperature change of the outer wall of the firing container filled with the phosphor material in a specific temperature range is small (that is, it means that no rapid exothermic reaction has occurred). is important. The specific temperature range is usually a temperature range from a temperature 100 ° C. lower than the melting point of the phosphor raw material alloy to a temperature 30 ° C. lower than the melting point, preferably 150 ° C. lower than the melting point, More preferably, the temperature range is 200 ° C. or more lower than the melting point, preferably the melting point or lower, more preferably 100 ° C. or higher.

  The range of temperature change per minute in the heating step of the production method of the present invention is usually within 50 ° C, preferably within 30 ° C, more preferably within 20 ° C, and even more preferably within 10 ° C. If the temperature change in the heating step is too large, the light emission characteristics of the phosphor tend to deteriorate, and in some cases, the phosphor may not be obtained. Although there is no restriction | limiting in particular in the minimum of the range of the temperature change per minute in the said heating process, Usually, it is 0.1 degreeC or more from a viewpoint of productivity. However, the temperature may be lowered in the heating step, and the numerical value of the “temperature change per minute in the heating step” indicates an absolute value.

Further, the above “temperature change per minute in the heating step” is the temperature of the outer wall of the baking container (however, the temperature is at a position near half the height filled with the phosphor material). In the following, this temperature may be referred to as the “side wall temperature of the firing vessel”), a tungsten-rhenium alloy thermocouple, a platinum thermocouple, a rhodium-platinum thermocouple, etc. at regular intervals. It is the value which measured using the radiation thermometer and calculated | required the temperature change per minute from this measured value by following formula [B].
Temperature change (℃ / min)
= Temperature at time T minutes-temperature at time (T-1) minutes [B]

In order to confirm that the temperature change represented by the formula [B] is not noise, it is preferable to monitor the temperature at intervals of some extent. Specifically, the temperature measurement interval is usually 30 seconds or shorter, preferably 20 seconds or shorter, more preferably 10 seconds or shorter. The lower limit of the temperature measurement interval is usually 1 second or longer.
Further, in the formula [B], the temperature change per minute is specified, but there is no particular limitation on the temperature measurement interval. For example, the range of the temperature change per 10 minutes is usually within 100 ° C., Preferably it is within 80 degreeC, More preferably, it is within 50 degreeC. Although there is no restriction | limiting in particular in the minimum of the range of the temperature change per 10 minutes, Usually, it is 0.5 degreeC or more.
It should be noted that the side wall temperature of the baking container substantially coincides with the furnace temperature when no rapid heat generation occurs during the heating process. Therefore, when the value of the formula [B] becomes larger than the change in the furnace temperature or the like, it usually means that a rapid exothermic reaction occurs.

  The production method of the present invention is not particularly limited as long as the above-described conditions are satisfied, but a method for adjusting a temperature change in the heating step will be described below.

When the amount of heat generated per certain time caused by the nitriding reaction is reduced (that is, when the rapid progress of the nitriding reaction is suppressed), the temperature change in the heating step can be adjusted to the above range. Specifically, the following methods 1) to 4) can be mentioned, and the production method of the present invention preferably satisfies at least one of the following 1) to 4), and particularly at least 1). It is preferable to satisfy.
Details of the following 1) to 4) will be described later.

1) Part or all of the phosphor raw material alloy is a nitrogen-containing alloy having a total metal element content of 97% by weight or less. 2) From the temperature lower than the melting point of the phosphor raw material alloy by 100 ° C. The heating rate in the temperature range up to a temperature lower by 30 ° C. is 9 ° C./min or less. 3) As the phosphor raw material, together with the phosphor raw material alloy, one or two metal elements constituting the phosphor Use nitride or oxynitride containing at least seeds 4) Use phosphor material alloy powder having an angle of repose of 45 degrees or less as the phosphor material alloy.

  The production method of the present invention may satisfy any two or more of the above 1) to 4) as necessary. Thereby, the emitted-heat amount per fixed time can further be reduced. When satisfying the above 1), in addition to the above 1), any one or more of the above 2) to 4) may be satisfied, and among them, the above 1) and 2) or the above It is preferable to satisfy 1) and 3) above. Or it is preferable to satisfy | fill said 2) and said 3). Since the degree of the effect obtained by the above 1) to 4) may differ depending on other conditions such as the composition and shape of the phosphor raw material alloy, the firing device, the firing atmosphere, and the firing temperature, the above 1) to 4) It is preferable to adjust the selection appropriately.

In order to increase the amount of the phosphor raw material to be processed at one time and to improve the light emission characteristics of the obtained phosphor, it is preferable to satisfy the above 1) to 4), but it is represented by the following formula [A]. By adjusting the ratio of the mass of the phosphor raw material to the mass of the firing container used for firing the phosphor raw material to an appropriate value, the above-mentioned 1) to 4) may not be satisfied, but the per minute in the heating step You may make it the range of a temperature change be less than 50 degreeC. Moreover, in addition to satisfy | filling any one of said 1) -4), you may adjust the temperature change per minute in the said heating process by adjusting the value of following formula [A]. .
(Mass of phosphor material) / {(Mass of firing container) + (Mass of phosphor material)} [A]

  That is, since the firing container has a function of absorbing heat emitted from the phosphor material, the heating step is performed by reducing the ratio of the mass of the phosphor material to the total mass of the firing container and the phosphor material. There is a tendency that the rapid exothermic reaction can be suppressed.

When the production method of the present invention does not satisfy any of the above 1) to 4), the preferable value of the formula [A] is the composition and shape of the phosphor raw material alloy used (particularly, the particle diameter of the alloy powder). ), Or depending on the total metal element content of the nitrogen-containing alloy and other production conditions, etc., but usually 0.01 or more, preferably 0.05 or more, and usually 0.5 or less, preferably 0. .2 or less.
When the production method of the present invention satisfies any one or more of the above 1) to 4), the value of the formula [A] is larger than the case where none of the above 1) to 4) is satisfied. Even in this case, a phosphor with high characteristics can be obtained. Specific numerical ranges are as follows.

When the production method of the present invention satisfies the above 1), the value of the formula [A] is usually 0.3 or more, particularly 0.4 or more, and usually 0.95 or less, especially 0.8 or less. Is preferable from the viewpoint of the characteristics of the obtained phosphor and the productivity.
Further, when the production method of the present invention satisfies the above 1) and 2), the value of the formula [A] is usually 0.35 or more, particularly 0.45 or more, and usually 0.95 or less, A range of 0.8 or less is preferable from the viewpoint of the characteristics of the obtained phosphor and productivity.
When the production method of the present invention satisfies the above 1) and 3), the value of the formula [A] is usually 0.35 or more, particularly 0.45 or more, and usually 0.6 or less. A range of 0.4 or less is preferable from the viewpoint of the characteristics of the obtained phosphor and productivity.
When the production method of the present invention satisfies the above 1) and 4), the value of the formula [A] is usually 0.1 or more, particularly 0.2 or more, and usually 0.8 or less, A range of 0.6 or less is preferable from the viewpoint of the characteristics of the obtained phosphor and productivity.

  In order to reduce the manufacturing cost, it is preferable to increase the amount of the phosphor raw material that can be processed at one time. Therefore, when the production method of the present invention is industrially implemented, the value of the formula [A] is set to 0.24 or more, preferably 0.4 or more, so that a high-quality phosphor can be obtained. It is preferable to adjust manufacturing conditions.

In the above formula [A], the quantity ratio between the phosphor raw material and the firing container is expressed using mass for convenience. However, more accurately, the value defined by the formula [A] is the following formula: Like [A ′], it is represented by the product of mass and specific heat (ie, heat capacity).
Mass of phosphor material (g) x specific heat /
{(Mass of firing container (g) × specific heat) + (Mass of phosphor material (g) × specific heat)}} [A ′]

Here, for example, the specific heat of the phosphor raw material alloy (Eu _0.008 Sr _0.792 Ca _0.2 AlSi) used in Example 1 is 0.71 J / K / g, and the specific heat of boron nitride (the material of the firing container) is 2 0.9 J / K / g, the specific heat of molybdenum is 0.26 J / K / g, the specific heat of alumina is 0.6 J / K / g, and the specific heat of aluminum nitride is 1.2 J / K / g.
Depending on the composition of the phosphor material, the specific heat of the phosphor material varies depending on the nitrogen-containing alloy, nitride, and / or oxynitride described later as the phosphor material. Although the value of A ′] varies, the value of the formula [A ′] is usually 0.05 or more, preferably 0.1 or more, and usually 0.9 or less, and preferably 0.75 or less. .

  Therefore, in order to increase the amount of heat absorbed by the firing container, it is preferable to use a material having a high thermal conductivity or a high specific heat as the firing container. Specifically, it is preferable to use a firing container made of boron nitride, molybdenum, alumina, or the like, and it is particularly preferable to use a firing container made of boron nitride.

  In addition, when it is desired to further increase the amount of the phosphor raw material to be processed at once, it is preferable to devise a method for reducing the amount of accumulated heat in the baking apparatus or baking container as much as possible. For example, by adjusting the distance between the firing container and the firing container to improve heat dissipation, providing a cooling device near the firing container, using a firing container with a large surface area, or adjusting the number of firing containers placed in the firing furnace By doing so, the amount of accumulated heat can be adjusted.

  Further, when the production method of the present invention is industrially carried out, the ratio of the volume of the phosphor material to the volume of the processing chamber of the baking apparatus (hereinafter referred to as “the filling rate of the phosphor material in the baking container”) is produced. It is important from the viewpoint of sex. The specific range of the ratio of the phosphor raw material volume to the processing chamber volume of the firing apparatus is usually 8% or more, preferably 20% or more, more preferably 25% or more, and usually 80% or less, preferably 60%. % Or less, more preferably 40% or less. When the filling rate of the phosphor raw material in the firing container is lower than this range, the phosphor is easily produced according to the present invention even if any one of the above 1) to 4) is not satisfied. Can be done, but productivity tends to be low. On the other hand, when the filling rate of the phosphor raw material in the baking container is higher than this range, the deterioration of the baking apparatus may be accelerated.

Below, each process of the manufacturing method of this invention is demonstrated in detail.
The above 1) to 4) will also be described in detail.

In the phosphor manufacturing method of the present invention, the phosphor of the present invention is manufactured through the following steps.
That is, first, a raw material metal or its alloy is weighed (raw material weighing step). Then, these raw materials are melted (melting step) and alloyed to produce a phosphor raw material alloy. Then, nitriding is performed by heating the phosphor raw material alloy in a nitrogen-containing atmosphere (heating step, also referred to as “secondary nitriding step” as appropriate). In addition to these processes, a casting process, a pulverizing process, a classification process, a primary nitriding process, a cooling process, and the like may be performed as necessary.
In addition, as a phosphor raw material alloy, the phosphor of the target composition should just be obtained, and 1 type, or 2 or more types of phosphor raw material alloys can be used.

In order to satisfy the above 1), a primary nitriding step may be performed, or a nitrogen-containing alloy described later may be added in the secondary nitriding step.
In order to satisfy the above 2), the temperature increase rate in the secondary nitriding step may be adjusted.
In order to satisfy the above 3), an oxide or oxynitride described later may be mixed in the secondary nitriding step.
In order to satisfy the above 4), a phosphor material having an angle of repose of 45 degrees or less by adopting a method (for example, gas atomizing method) having the following steps (a) to (c) in the pulverization step: An alloy powder for the phosphor may be obtained or an alloy powder for a phosphor raw material having an angle of repose of 45 degrees or less in the secondary nitriding step may be used.

[I] Production of phosphor raw material alloy {weighing raw materials}
For example, when a phosphor having a composition represented by the following general formula [1] is produced using the phosphor production method of the present invention, the raw material is made to have the following general formula [3]. It is preferable to produce an alloy for a phosphor raw material by weighing a metal to be used and an alloy thereof (hereinafter sometimes simply referred to as “raw metal”).
M ¹ _a M ² _b M ³ _c M ⁴ _d ... [3]
(However, M ¹ , M ² , M ³ , M ⁴ , a, b, c and d have the same meanings as those in the general formula [1] described below.)

As a raw material, a metal, an alloy of the metal, or the like can be used. Moreover, only 1 type may be used for the raw material corresponding to the element which the fluorescent substance of this invention contains, respectively, and 2 or more types may be used together by arbitrary combinations and a ratio. However, among the raw materials, as the Eu raw material and Ce raw material used as a raw material of the activating element M ^1, it is preferable to use Eu metal or Ce metal. This is because it is easy to obtain raw materials.

The purity of the metal used for the production of the alloy is preferably high. Specifically, from the viewpoint of the light emission characteristics of the phosphor to be synthesized, the metal raw material of the activator element M ^{1 is} a metal whose impurity is refined to 0.1 mol% or less, preferably 0.01 mol% or less. It is preferable to use it. As the raw material of the activator elements M ¹ other elements, divalent, trivalent, using a tetravalent various metals. For the same reason as activator elements M ^1, preferably both the concentration of impurities contained in more than 0.1 mol%, more preferably not more than 0.01 mol%. For example, when at least one selected from the group consisting of Fe, Ni, and Co is contained as an impurity, the content of each element is usually 500 ppm or less, preferably 100 ppm or less.

  Although there is no restriction | limiting in the shape of a raw material metal, Usually, the thing of a granular form or a lump shape with a diameter of several mm to several dozen mm is used. In addition, the thing of diameter 10mm or more is called the lump form here, and the thing below it is called the granular form.

When using the divalent alkaline earth metal element as the metal element M ^2, as a raw material thereof, granular, but shapes such as bulk is not limited, it is preferable to select an appropriate shape depending on the chemical nature of the material. For example, Ca is stable in the atmosphere in either a granular form or a lump, and can be used. However, since Sr is chemically more active, it is preferable to use a lump raw material.

  In addition, about the metal element lost by volatilization, reaction with the material of a crucible, etc. at the time of melting | dissolving, you may weigh and add beforehand beforehand as needed.

{Melting raw materials}
After the raw materials are weighed, the raw materials are melted and alloyed to produce a phosphor raw material alloy (melting step). The obtained phosphor raw material alloy contains two or more metal elements constituting the phosphor produced in the present invention (hereinafter sometimes referred to as “the phosphor of the present invention”). In addition, even if one phosphor raw material alloy does not contain all the metal elements constituting the phosphor of the present invention, two or more kinds of alloys and / or metals in the primary nitriding step or the secondary nitriding step described later By using together, the phosphor of the present invention can be produced.

  There is no restriction | limiting in particular in the method of fuse | melting raw material metal, Arbitrary methods can be employ | adopted. For example, a resistance heating method, an electron beam method, an arc melting method, a high frequency induction heating method (hereinafter sometimes referred to as “high frequency melting method”), and the like can be used. It is also possible to melt these methods in any combination of two or more.

  Examples of the crucible material that can be used during melting include alumina, calcia, graphite, and molybdenum.

However, in particular, when producing the alloy for phosphor precursor containing an alkaline earth metal element as Si and divalent metal elements M ^2, it is preferred to note the following points.

That is, the melting point of Si is 1410 ° C., which is similar to the boiling point of alkaline earth metals (for example, Ca has a boiling point of 1494 ° C., Sr has a boiling point of 1350 ° C., and Ba has a boiling point of 1537 ° C.). In particular, since the boiling point of Sr is lower than the melting point of Si, it is extremely difficult to simultaneously melt Sr and Si.
Therefore, in the present invention, the Si raw material (that is, Si and / or an alloy containing Si) is first melted, and then the alkaline earth metal raw material (that is, the alkaline earth metal and / or the alkaline earth metal is added). It is preferable to melt the alloy. Thereby, both the alkaline earth metal raw material and the Si raw material can be melted together. Furthermore, by melting the alkaline earth metal raw material after melting the Si raw material in this way, the purity of the resulting phosphor raw material alloy is improved, and the characteristics of the phosphor using the raw material as a raw material are remarkably improved. The effect of doing.

  Hereinafter, the case of manufacturing the phosphor raw material alloy containing Si and the alkaline earth metal element will be described in detail.

  When producing a phosphor raw material alloy containing Si and an alkaline earth metal element, there is no limitation on the melting method, the above melting method can be arbitrarily adopted, among them, arc melting method, high-frequency melting method is preferable, High frequency melting is particularly preferred. Hereinafter, the case of (1) arc melting / electron beam melting and (2) high frequency melting will be described in more detail as an example.

(1) In the case of arc melting method / electron beam melting method In the case of arc melting / electron beam melting, melting is performed according to the following procedure.
i) An Si metal or an alloy containing Si is melted by an electron beam or arc discharge.
ii) Next, the alkaline earth metal is melted by indirect heating to obtain an alloy containing Si and the alkaline earth metal.
Here, after the alkaline earth metal is dissolved in the molten metal containing Si, mixing may be promoted by heating and / or stirring with an electron beam or arc discharge.

(2) In the case of high-frequency melting method Since an alloy containing an alkaline earth metal element has high reactivity with oxygen, it must be melted in a vacuum or an inert gas, not in the atmosphere. Under such conditions, the high frequency melting method is usually preferred. However, Si is a semiconductor and is difficult to melt by induction heating using high frequency. For example, the resistivity of aluminum at 20 ° C. is 2.8 × 10 ⁻⁸ Ω · m, while the resistivity of polycrystalline Si for semiconductor is 10 ⁵ Ω · m or more. Since it is difficult to directly melt a material having such a large specific resistivity at a high frequency, generally, a conductive susceptor is used, and heat is transferred to Si by heat conduction or radiation to melt.

  There is no limitation on the shape of the susceptor, and a disk shape or a tubular shape is possible, but it is preferable to use a crucible.

The material of the susceptor is not limited as long as the raw material can be melted, and graphite, molybdenum, silicon carbide and the like are generally used. However, they are very expensive and have a problem that they easily react with alkaline earth metals. On the other hand, crucibles (such as alumina and calcia) that can melt alkaline earth metals are insulators and are difficult to use as susceptors. Therefore, in preparing alkaline earth metal and Si metal in a crucible and melting at high frequency, using a known conductive crucible (such as graphite) as a susceptor, Si metal and alkaline earth metal It is difficult to melt at the same time. Therefore, this problem is solved by melting in the following order.
i) The Si metal is melted by indirect heating using a conductive crucible.
ii) Next, an alkaline earth metal is melted by using an insulating crucible to obtain an alloy containing Si and an alkaline earth metal element.

  The Si metal may be cooled between the steps i) and ii), or the alkaline earth metal may be continuously melted without being cooled. When performing continuously, a crucible coated with calcia, alumina or the like suitable for melting an alkaline earth metal in a conductive container can be used.

More specific steps are described as follows.
i) Si metal and metal M (for example, Al, Ga) are melted by indirect heating using a conductive crucible to obtain a conductive alloy (mother alloy).
ii) Next, after melting the mother alloy of i) using an alkaline earth metal resistant crucible, the alloy containing Si and the alkaline earth metal element is obtained by melting the alkaline earth metal at high frequency. obtain.

  As a specific method for melting the Si metal or the Si-containing master alloy first and then melting the alkaline earth metal, for example, the Si metal or Si-containing master alloy is first melted, and then the alkaline earth metal is melted there. And the like.

Further, Si can be alloyed with a metal M other than the divalent metal element M ² to impart conductivity. In this case, the melting point of the obtained alloy is preferably lower than that of Si. An alloy of Si and Al is particularly preferable because the melting point is around 1010 ° C. and the melting point is lower than the boiling point of the alkaline earth metal element.

When a mother alloy of Si and a metal M other than the divalent metal element M ² is used, the composition is not particularly limited, but the mother alloy preferably has conductivity. In this case, the mixing ratio (molar ratio) of Si and the metal M is such that the metal M is usually in the range of 0.01 or more and 5 or less when the number of moles of Si is 1. It is preferable to produce a mother alloy having a melting point lower than the boiling point of the metal group element.
In addition, Si metal can also be added to the master alloy containing Si.

In the present invention, other than melting the alkaline earth metal after melting the Si metal, there is no particular limitation on the melting time of the other raw metal, but usually a large amount or a high melting point Thaw first.
In order to disperse the activation element M ¹ uniformly and the addition amount of the activation element M ¹ is small, it is preferable to melt the raw material metal of the activation element M ¹ after melting the Si metal.

In the case of producing a phosphor raw material alloy represented by the above general formula [3], in which the tetravalent metal element M ⁴ is Si and at least Sr is contained as the divalent metal element M ² , the following procedure is performed. It is preferable to melt with.
(1) preparing a mother alloy of Si and trivalent metal elements M ^3. At this time, preferably Si and 3
The valent metal element M ³ is alloyed at the Si: M ³ ratio in the general formula [3].
(2) After melting the master alloy of (1), melt Sr.
(3) Thereafter, the divalent metal elements other than Sr, to melt the activator elements M ^1.

By the way, even when any raw material is melted, the specific temperature condition and melting time at the time of melting the raw material may be set to an appropriate temperature and time according to the raw material to be used.
The atmosphere at the time of melting the raw material is arbitrary as long as the phosphor raw material alloy is obtained, but an inert gas atmosphere is preferable, and an argon atmosphere is particularly preferable. In addition, only 1 type may be used for an inert gas and it may use 2 or more types together by arbitrary combinations and a ratio.
Furthermore, the pressure at the time of melting the raw material is arbitrary as long as the phosphor raw material alloy is obtained, but it is preferably 1 × 10 ³ Pa or more, and preferably 1 × 10 ⁵ Pa or less. Furthermore, it is desirable to carry out under atmospheric pressure from the viewpoint of safety.

{Casting of molten metal}
An alloy for a phosphor raw material is obtained by melting the raw material. This phosphor raw material alloy is usually obtained as a molten alloy, but there are many technical problems in producing a phosphor directly from this molten alloy. Therefore, it is preferable to obtain a solidified body (hereinafter referred to as “alloy lump” as appropriate) through a casting process in which the molten alloy is poured into a mold and molded.

  However, in this casting process, segregation occurs due to the cooling rate of the molten metal, and a composition that has a uniform composition in the molten state may have an uneven composition distribution. Therefore, it is desirable that the cooling rate be as fast as possible. The mold is preferably made of a material having good thermal conductivity such as copper, and preferably has a shape in which heat is easily dissipated. It is also preferable to devise cooling the mold by means such as water cooling if necessary.

  By such a device, for example, it is preferable to use a mold having a large bottom area with respect to the thickness and solidify as soon as possible after pouring the molten metal into the mold.

  Also, since the degree of segregation varies depending on the composition of the alloy, it is necessary to prevent segregation by collecting samples from several places of the obtained solidified body by using necessary analytical means such as ICP emission spectroscopy. It is preferable to set a proper cooling rate.

  The atmosphere during casting is preferably an inert gas atmosphere, and an argon atmosphere is particularly preferable. At this time, only one kind of inert gas may be used, or two or more kinds may be used in any combination and ratio.

{Crushing of alloy lump}
Prior to the heating step, the phosphor raw material alloy is preferably powdered with a desired particle size. Therefore, the alloy lump obtained in the casting process is then pulverized (pulverization process), so that it may be referred to simply as “alloy powder for phosphor raw material having a desired particle size and particle size distribution (hereinafter simply referred to as“ alloy powder ”). .).

  Although there is no restriction | limiting in particular in the grinding | pulverization method, For example, it is possible to carry out by the dry method and the wet method using organic solvents, such as ethylene glycol, hexane, and acetone.

Hereinafter, the dry method will be described in detail as an example.
This pulverization step may be divided into a plurality of steps such as a coarse pulverization step, a medium pulverization step, and a fine pulverization step as necessary. In this case, the entire pulverization process can be pulverized using the same apparatus, but the apparatus used may be changed depending on the process.

  Here, the coarse pulverization step is a step of pulverizing so that approximately 90% by weight of the alloy powder has a particle size of 1 cm or less. Can be used. The middle pulverization step is a step of pulverizing so that approximately 90% by weight of the alloy powder has a particle size of 1 mm or less, and a pulverizer such as a cone crusher, a crushing roll, a hammer mill, or a disk mill can be used. . The fine pulverization step is a step of pulverizing the alloy powder so as to have a weight median diameter, which will be described later. Can be used.

  Among these, from the viewpoint of preventing impurities from being mixed, it is preferable to use a jet mill in the final pulverization step. In order to use a jet mill, the alloy lump is preferably pulverized in advance until the particle size is about 2 mm or less. In the jet mill, the particles are pulverized mainly by using the expansion energy of the fluid injected from the nozzle original pressure to the atmospheric pressure. Therefore, the particle size can be controlled by the pulverization pressure, and contamination of impurities can be prevented. Is possible. Although the pulverization pressure varies depending on the apparatus, it is usually in the range of 0.01 MPa or more and 2 MPa or less in gauge pressure. Among them, 0.05 MPa or more and less than 0.4 MPa is preferable, and 0.1 MPa or more and 0.3 MPa or less. Is more preferable. If the gauge pressure is too low, the particle size of the obtained particles may be too large, and if it is too high, the particle size of the obtained particles may be too small.

  Furthermore, in any case, it is necessary to appropriately select the relationship between the material of the pulverizer and the object to be crushed so that impurities such as iron do not enter during the pulverization process. For example, the contact portion is preferably provided with a ceramic lining, and among ceramics, alumina, silicon nitride, tungsten carbide, zirconia and the like are preferable.

  In order to prevent oxidation of the alloy powder, the pulverization step is preferably performed in an inert gas atmosphere. Although there is no restriction | limiting in particular in the kind of inert gas, Usually, 1 type single atmosphere or 2 or more types mixed atmosphere can be used among gases, such as nitrogen, argon, and helium. Among these, nitrogen is particularly preferable from the viewpoint of economy.

  Further, the oxygen concentration in the atmosphere is not limited as long as the oxidation of the alloy powder can be prevented, but it is usually preferably 10% by volume or less, particularly preferably 5% by volume or less. Moreover, as a minimum of oxygen concentration, it is about 10 ppm normally. By setting the oxygen concentration within a specific range, it is considered that an oxide film is formed on the surface of the alloy during pulverization and stabilized. When the pulverization step is performed in an atmosphere having an oxygen concentration higher than 5% by volume, dust may explode during the pulverization. Therefore, it is preferable to provide equipment that does not generate dust.

  In addition, you may cool as needed so that the temperature of an alloy powder may not rise during a grinding | pulverization process.

{Classification of alloy powder}
The alloy powder obtained as described above is obtained by using, for example, a sieving device using a mesh such as a vibratory screen or a shifter; an inertia classifier such as an air separator; a centrifuge such as a cyclone, etc. After adjusting to the desired weight median diameter D ₅₀ and particle size distribution (classification step), it is preferably used for the subsequent steps.

  In adjusting the particle size distribution, the coarse particles are preferably classified and recycled to a pulverizer, and the classification and / or recycling is more preferably continuous.

  This classification step is also preferably performed in an inert gas atmosphere. Although there is no restriction | limiting in particular in the kind of inert gas, Usually, 1 type single atmospheres, such as nitrogen, argon, helium, or 2 or more types of mixed atmospheres are used, and nitrogen is especially preferable from a viewpoint of economical efficiency. The oxygen concentration in the inert gas atmosphere is preferably 10% by volume or less, particularly preferably 5% by volume or less.

The alloy powder used in the primary nitriding step and the secondary nitriding step described later needs to adjust the particle size according to the activity of the metal element constituting the alloy powder, and the weight median diameter D ₅₀ is usually 100 μm. In the following, it is preferably 80 μm or less, particularly preferably 60 μm or less, 0.1 μm or more, preferably 0.5 μm or more, particularly preferably 1 μm or more. Further, when the alloy contains Sr, the reactivity with the atmospheric gas is high, so the weight median diameter D ₅₀ of the alloy powder is usually 5 μm or more, preferably 8 μm or more, more preferably 10 μm or more, and particularly preferably 13 μm. It is desirable to set it above. When the particle size of the alloy powder is smaller than the above-mentioned range of the weight median diameter D ₅₀ , the heat generation rate during the reaction such as nitriding tends to increase, and the control of the reaction becomes difficult. May be easily oxidized in the atmosphere, and may be difficult to handle, for example, oxygen may be easily taken into the obtained phosphor. On the other hand, if the particle size of the alloy powder is greater than the range of the weight-average median diameter D ₅₀ of the above, there are cases where reaction such as nitriding inside the alloy particles may be insufficient.

The ratio of alloy particles having a particle size of 10 μm or less contained in the alloy powder is preferably 80% by weight or less, and the ratio of alloy particles having a particle size of 45 μm or more is preferably 40% by weight or less.
The value of QD is not particularly limited, but is usually 0.59 or less. Here, QD is defined as QD = (D ₇₅ −D ₂₅ ) / (D ₇₅ + D ₂₅ ), where the particle size values when the integrated values are 25% and 75% are expressed as D ₂₅ and D ₇₅ , respectively. To do. A small QD value means a narrow particle size distribution.

[II] Heating step In the present invention, the phosphor raw material alloy obtained as described above (wherein the phosphor raw material alloy may be in the form of powder or lump, It is preferably an alloy powder for a phosphor raw material.) And / or a nitrogen-containing alloy described later is nitrided by heating in a nitrogen-containing atmosphere. In the heating step, a secondary nitriding step described later is essential, and the following primary nitriding step is performed as necessary.

{Primary nitriding process}
From the viewpoint of industrially efficiently producing the phosphor of the present invention, when a production method satisfying the above 1) is desired, a primary nitriding step is performed before the secondary nitriding step, if necessary. This primary nitriding step is a step of manufacturing a nitrogen-containing alloy described later by nitriding alloy powder (however, it may be a granular or massive alloy). Specifically, it is a step of preliminary nitriding by heating the alloy powder for a predetermined time in a predetermined temperature range in a nitrogen-containing atmosphere. By introducing such a primary nitriding step, the reactivity between the alloy and nitrogen in the secondary nitriding step described later can be controlled, and a phosphor can be industrially produced from the alloy.

By nitriding the alloy powder in this step, the material is converted from the phosphor raw material alloy to the nitrogen-containing alloy, and the weight thereof is increased. In this specification, the weight increase of the alloy powder at this time is represented by the weight increase rate represented by the following formula [4].
(Weight of nitrogen-containing alloy after primary nitriding step-weight of alloy powder before primary nitriding step)
/ Weight of alloy powder before primary nitriding step × 100 ... [4]

In this step, the degree of nitriding can be controlled by reaction conditions such as nitrogen partial pressure, temperature, and heating time.
Although it varies depending on the reaction conditions of the secondary nitriding step, which will be described later, the composition of the alloy powder, etc., the weight increase rate of the alloy powder obtained by the above formula [4] is usually 0.5% by weight or more, particularly 1% by weight or more In particular, the reaction conditions are preferably adjusted so as to be 5% by weight or more. Moreover, although there is no restriction | limiting in particular in the upper limit of a weight increase rate, In theory, it is usually 40 weight% or less, Preferably it is 31 weight% or less. In order to adjust the weight increase rate of the alloy powder to be within the above range, the primary nitriding step can be repeated twice or more. When the primary nitriding step is repeated, there is no particular limitation on the number of times, but considering the manufacturing cost, it is usually 3 times or less, preferably 2 times or less.

Further, the primary nitriding step can be performed by a continuous method or a batch method. Since preferable reaction conditions differ between the continuous method and the batch method, the reaction conditions of the primary nitriding step will be described separately for the case of the continuous method and the case of the batch method.
In addition, it is preferable to carry out by a continuous system rather than a batch system from a viewpoint of productivity. That is, when the primary nitriding step is performed in a continuous mode, it is preferable to circulate a higher concentration of nitrogen and heat at a higher temperature and in a shorter time than in the batch mode.

<Continuous method>
(Device type)
When the primary nitriding step is performed in a continuous manner, for example, a rotary kiln, a tunnel furnace, a belt furnace, a fluidized firing furnace or the like can be used, and among these, a rotary kiln is preferably used.
When the rotary kiln method is used, the alloy powder is heated while rotating a refractory cylindrical furnace core tube in which a nitrogen-containing gas is circulated. By inclining the core tube and continuously supplying the alloy powder, continuous processing becomes possible. When a rotary kiln is used, the alloy powder can be stirred during heating, so that fusion between the alloy powders can be suppressed and gas-solid contact efficiency can be improved. As a result, the heating time can be shortened and uniform nitriding can be realized. The rotary kiln preferably has a structure in which atmospheric gas can flow, and more preferably can control the residence time and charging speed of the alloy powder.
Note that, using a vertical furnace, the alloy powder may be nitrided while being dropped in a nitrogen atmosphere.

  The rotational speed of the furnace core tube is arbitrary as long as a nitrogen-containing alloy is obtained, but is usually 1 rpm or more, preferably 2 rpm or more, particularly preferably 3 rpm or more, and usually 100 rpm or less, preferably 20 rpm or less, particularly preferably 8 rpm or less. is there. Outside this range, it may be difficult to control the dynamics of the alloy powder in the furnace core tube. That is, if the rotational speed is too slow, the alloy powder tends to adhere to and stay on the inner wall of the core tube. On the other hand, if the rotational speed is too high, the alloy powder does not fall while being pressed against the inner wall of the core tube due to centrifugal force, and the stirring efficiency tends to decrease.

  The inclination angle of the furnace core tube with respect to the horizontal is arbitrary as long as a nitrogen-containing alloy is obtained, but is usually 0.6 ° or more, preferably 1 ° or more, particularly preferably 1.7 ° or more, and usually 6 ° or less, preferably Is 5 ° or less, particularly preferably 3.4 ° or less. Outside this range, the supply rate of the alloy powder tends to be difficult to control.

  When the primary nitriding step is performed using a rotary kiln, it is preferable to prevent adhesion of the alloy powder to the core tube. That is, when the alloy powder adheres to the core tube, discharge of the object to be processed may be hindered, and stable processing may be difficult. In addition, when the core tube is heated from the outside with a heater or the like, if the alloy powder adheres to the core tube, the deposit may act as a heat insulating material, and the heating temperature may be substantially reduced. When the core tube is cooled after completion of the primary nitriding process, the deposits may be removed by peeling due to the difference in thermal expansion coefficient between the core tube and the alloy powder. In order to maintain a constant level of nitriding in the primary nitriding process, always apply deposits such as applying vibration to the core tube to peel off deposits or physically scraping off deposits. It is more preferable to continue removing.

(Material of equipment)
In an apparatus used in a continuous mode, the material of the parts that come into contact with the alloy powder such as a firing vessel and a furnace core tube is arbitrary as long as a nitrogen-containing alloy is obtained. For example, aluminum oxide, boron nitride, graphite, calcium oxide, magnesium oxide , Molybdenum, tungsten, or the like can be used. Quartz can also be used when the temperature during use is approximately 1100 ° C. or lower. Among these, as the material for the core tube, aluminum oxide and boron nitride are particularly preferable. In addition, the said material may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Atmosphere during heating)
The atmosphere during heating must contain nitrogen element, and it is preferable to circulate a gas in which nitrogen gas and an inert gas other than nitrogen are mixed. Especially, nitrogen and rare gas elements such as argon are mixed. It is preferable to distribute the gas. This is because the reaction rate can be controlled by mixing an inert gas with nitrogen gas. In addition, the said inert gas may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  Although the nitrogen concentration in the atmosphere is arbitrary as long as a nitrogen-containing alloy is obtained, it is usually 0.1% by volume or more, preferably 1% by volume or more, more preferably 3% by volume or more, and there is no particular upper limit. , Preferably it is 80 volume% or less. If the nitrogen concentration in the atmosphere is too low, the progress of nitriding may be insufficient. On the other hand, if the nitrogen concentration is too high, it may be difficult to control the heating temperature, or the alloy may adhere to the core tube, etc. May increase.

  The oxygen concentration in the atmosphere is arbitrary as long as a nitrogen-containing alloy is obtained, but is usually 300 ppm or less, preferably 100 ppm or less, and preferably close to 0, but usually 0.1 ppm or more, preferably 1 ppm or more. is there. If the oxygen concentration in the atmosphere is too high, oxygen may be mixed into the nitrogen-containing alloy and further to the finally obtained phosphor, and the emission peak wavelength may be shortened or the luminance may be reduced.

  For the purpose of avoiding the mixing of oxygen, it is preferable to mix a reducing gas (for example, hydrogen, carbon monoxide, hydrocarbon, ammonia, etc.) in an amount that does not reach the explosion limit. In addition, reducing gas may be used individually by 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  Although the pressure at the time of heating is arbitrary as long as a nitrogen-containing alloy is obtained, in order to prevent mixing of oxygen in air | atmosphere, it is preferable to set it as the pressure more than atmospheric pressure. If the pressure is too low, if the heating furnace is poorly sealed, a large amount of oxygen may be mixed and a high-quality phosphor may not be obtained.

  The nitrogen partial pressure in the atmosphere during heating is arbitrary as long as a nitrogen-containing alloy is obtained, but is usually atmospheric pressure or lower, preferably 0.09 MPa or lower, more preferably 0.08 MPa or lower, and usually 0.0005 MPa. Above, preferably 0.001 MPa or more. The higher the nitrogen partial pressure, the higher the nitriding rate, but if the nitrogen partial pressure is too high, the heat generation rate will be too high, the temperature of the alloy powder will exceed the melting point of the alloy forming the alloy powder, and the alloy particles will melt. Nitriding may not proceed uniformly. On the other hand, if the nitrogen partial pressure is too low, industrial problems arise, such as the time required for the primary nitriding step becomes longer and the amount of atmospheric gas consumed (for example, argon gas, etc.) increases. In addition, Sr and the like may volatilize from the alloy and the composition may shift.

(Nitrogen supply rate / speed)
In the case of a continuous method, it is preferable that a predetermined amount of alloy powder is supplied into the apparatus per unit time. Further, in order to nitride the supplied alloy powder to a desired level, at least a theoretically necessary amount of nitrogen per unit time is supplied into the apparatus. Specifically, the weight of the alloy powder supplied per unit time is usually 5% by weight or more, preferably 10% by weight or more, and the upper limit is not particularly limited, but usually 200% by weight or less of nitrogen is used. The nitrogen-containing atmospheric gas contained is preferably supplied into the apparatus.
The flow direction of the nitrogen-containing atmosphere gas may be countercurrent or cocurrent with respect to the supply direction of the alloy powder, but is usually countercurrent.

(Heating conditions)
The heating temperature is arbitrary as long as a nitrogen-containing alloy is obtained, but it is usually at least 150 ° C. lower than the melting point of the phosphor raw material alloy, preferably at least 100 ° C. lower than the melting point of the phosphor raw material alloy, Is preferably heated in a temperature range of 10 ° C. or lower than the melting point of the phosphor raw material alloy. The specific heating temperature varies depending on the composition of the alloy, but is usually 800 ° C. or higher, preferably 900 ° C. or higher, and usually 2500 ° C. or lower, preferably 1500 ° C. or lower. If the heating temperature is too low, the progress of the nitriding reaction tends to be insufficient, while if the temperature is too high, the adhesion of the alloy powder to the furnace core tube tends to increase. Here, the heating temperature refers to the core tube temperature at the time of heating.

  Further, the temperature lower by 100 ° C. than the melting point of the phosphor raw material alloy means the temperature at which the nitriding of the phosphor raw material alloy is started.

  In the present specification, the melting point of an alloy such as a phosphor raw material alloy or a nitrogen-containing alloy is the thermogravimetric-differential thermal analysis (hereinafter referred to as thermogravimetric-differential thermal analysis). (It is abbreviated as “TG-DTA” as appropriate.) It can be obtained from an endothermic peak by measurement and varies depending on the composition of the alloy, but is approximately 900 ° C. or higher and 1300 ° C. or lower, although it does not show a clear melting point. In this case, the decomposition start temperature is regarded as the melting point of the alloy, and when a plurality of types of alloys are used, the melting point of the alloy having the lowest melting point is set as the melting point of the alloy.

  The time for heating in the above temperature range (holding time at the maximum temperature) is arbitrary as long as a nitrogen-containing alloy is obtained, but is usually 0.1 minutes or more, preferably 1 minute or more, and usually 1 hour or less, preferably Is 30 minutes or less, more preferably 8 minutes or less. If the heating time is too long, the composition may shift due to volatilization of the alkaline earth metal, and if the heating time is too short, the progress of nitriding may be insufficient.

<For batch method>
(Device type)
When the primary nitriding step is performed in a batch system, for example, a tubular furnace, a general atmosphere heating furnace, a rotary kiln, or the like can be used. As a specific operation, the alloy powder is usually filled in a fireproof firing container (such as a tray or a crucible) and then heated in the apparatus.

(Baking container)
The shape of the firing container filled with the alloy powder is arbitrary as long as a nitrogen-containing alloy can be obtained, but it is not a sealed structure and the packed bed height is too high so that the contact efficiency between the firing atmosphere and the alloy powder is increased. None is preferred. The packed bed height is usually 30 mm or less, preferably 20 mm or less, more preferably 15 mm or less, and usually 3 mm or more, preferably 5 mm or more. This is because if the packed bed height is too high, the nitriding reaction may not proceed uniformly, whereas if the packed bed height is too low, the productivity may decrease.

  The material of the portion that comes into contact with the alloy powder such as a firing vessel is arbitrary as long as a nitrogen-containing alloy is obtained. For example, aluminum oxide, boron nitride, graphite, calcium oxide, magnesium oxide, molybdenum, tungsten, or the like can be used. . Quartz can also be used when the temperature during use is approximately 1100 ° C. or lower. Among these, graphite, aluminum oxide, boron nitride, and quartz are preferably used, and boron nitride is more preferably used. In addition, the said material may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

(Atmosphere during heating)
The atmosphere during heating is preferably an atmosphere in which a nitrogen atmosphere and an inert gas atmosphere are mixed. In particular, an atmosphere in which nitrogen and a rare gas element such as argon are mixed is preferable. This is because the reaction rate can be controlled by mixing an inert gas atmosphere with a nitrogen atmosphere. In addition, the said inert gas may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.

  The nitrogen concentration in the atmosphere is arbitrary as long as a nitrogen-containing alloy is obtained, but is usually 0.1% by volume or more, preferably 1% by volume or more, more preferably 3% by volume or more, and usually 99% by volume or less, preferably Is 20% by volume or less, more preferably 10% by volume or less. If the nitrogen concentration in the atmosphere is too low, alkaline earth metals and the like may volatilize. On the other hand, if the nitrogen concentration is too high, the progress of nitriding may be uneven.

  The oxygen concentration in the atmosphere is arbitrary as long as a nitrogen-containing alloy is obtained, but is usually the same as in the continuous method.

  As in the case of the continuous method, it is preferable to mix an amount of reducing gas (hydrogen, carbon monoxide, hydrocarbon, ammonia, etc.) that does not reach the explosion limit.

  Although the pressure at the time of heating is arbitrary as long as a nitrogen-containing alloy is obtained, it is preferable to set it as a pressure more than atmospheric pressure in order to prevent mixing of oxygen in air | atmosphere like the case of a continuous system.

  The nitrogen partial pressure in the atmosphere during heating is arbitrary as long as a nitrogen-containing alloy is obtained, but is usually the same as in the continuous method.

(Heating conditions)
The heating temperature is arbitrary as long as a nitrogen-containing alloy is obtained, but it is usually at least 150 ° C. lower than the melting point of the phosphor raw material alloy, preferably at least 100 ° C. lower than the melting point of the phosphor raw material alloy, Is heated below the melting point of the phosphor raw material alloy, preferably below 10 ° C. below the melting point of the phosphor raw alloy, more preferably below 50 ° C. below the melting point of the phosphor raw alloy. The specific heating temperature varies depending on the alloy composition, but is usually 800 ° C. or higher, preferably 900 ° C. or higher, and usually 2500 ° C. or lower, preferably 1500 ° C. or lower. If the heating temperature is too low, it tends to take a long time to complete the primary nitriding step, and in some cases, the progress of nitriding may be incomplete. On the other hand, if the heating temperature is too high, it may be difficult to control the nitriding reaction in the primary nitriding step, and the progress of nitriding may become uneven. Further, when heating is performed at a temperature near the melting point of the phosphor raw material alloy, the alloy powder adheres to the container or the alloy particles are fused, so that the contact efficiency with nitrogen tends to decrease. Here, the heating temperature refers to the temperature in the furnace during heating.

  The melting point of the alloy is as described in the section for the continuous method.

  Although the heating time varies depending on other conditions such as the type of apparatus and heating temperature, it tends to require a longer heating time than in the case of performing it continuously, and is usually 10 minutes or more, preferably 20 minutes or more, and usually 48 hours or less. If the heating time is too long, the composition may shift due to volatilization of the alkaline earth metal. If the heating time is too short, the progress of nitriding may be insufficient. Here, the heating time refers to the holding time at the maximum temperature.

  Further, in the temperature range from a temperature 150 ° C. lower than the melting point of the phosphor raw material alloy to a temperature 10 ° C. lower than the melting point of the phosphor raw material alloy, it is preferable to raise the temperature slowly. The temperature rising rate in this temperature range is usually 9 ° C./min or less, preferably 7 ° C./min or less, and the lower limit of the temperature rising rate is not particularly limited, but from the viewpoint of productivity, It is preferably 0.1 ° C./min or more, particularly 0.5 ° C./min or more.

  In addition, there is no restriction | limiting in particular about the temperature rising conditions from the time of a heating start to 150 degreeC lower temperature than melting | fusing point of the alloy for fluorescent material raw materials, It may heat up rapidly or slowly, but depending on the case, In consideration of the responsiveness to the temperature control of the firing apparatus, the temperature increase rate may be reduced to 9 ° C./min or less from a temperature lower than 150 ° C. lower than the melting point of the phosphor raw material alloy.

(Nitrogen-containing alloy)
In the present specification, the nitrogen-containing alloy refers to an alloy after completion of the above-described primary nitriding step.
The nitrogen-containing alloy contains two or more metal elements constituting the phosphor of the present invention. Further, the nitrogen-containing alloy mainly contains nitrogen as a component other than the metal element. As an index representing the degree of nitriding, the total metal element content (wt%) obtained by the following formula [5] can be used. It shows that nitriding is progressing, so that this all-metal element content rate is small.
Total metal element content (wt%)
= 100-{(weight of nitrogen-containing alloy after primary nitriding step-weight of alloy before primary nitriding step)
/ Weight of nitrogen-containing alloy after primary nitriding step} × 100 (5)

  The total metal element content (% by weight) of the nitrogen-containing alloy is the content of all metal elements contained in the nitrogen-containing alloy. The specific range is arbitrary as long as the phosphor of the present invention can be obtained, but is usually 60% by weight or more, preferably 70% by weight or more, more preferably 76% by weight or more, and usually 97% by weight or less, preferably It is 95 weight% or less, More preferably, it is 93 weight% or less. If the total metal element content is larger than the above range, the effect of the primary nitriding step may not be obtained. Also, it is theoretically unlikely that the total metal element content is smaller than the above range.

Further, the degree of nitriding of the nitrogen-containing alloy can be defined using the nitrogen content (% by weight). The nitrogen content can be obtained, for example, by measuring the nitrogen content with an oxygen-nitrogen simultaneous analyzer (manufactured by Leco) and using the following equation [6].
Nitrogen content of nitrogen-containing alloy (wt%)
= (Nitrogen content / weight of nitrogen-containing alloy) x 100 ... [6]

Although the specific range of the nitrogen content calculated | required by said Formula [6] is arbitrary as long as the fluorescent substance of this invention is obtained, it is 1 weight% or more normally, Preferably it is 2 weight% or more, More preferably, it is 5 weight%. In addition, it is usually 31% by weight or less, preferably 25% by weight or less. If the nitrogen content is too small, suppression of heat generation in the secondary nitriding process described later may be insufficient, and if it is too large, it may be uneconomical in terms of time and energy.
When a nitrogen-containing alloy having a nitrogen content calculated by the above formula [6] is 10% by weight or more, preferably 12% by weight or more is used as a phosphor raw material, an effect of suppressing heat generation in the secondary nitriding process described later. This is particularly preferable because it has a tendency to produce a high-quality phosphor regardless of the value of the formula [A].

Further, the nitrogen-containing alloy preferably further satisfies the following formula [7].
0.03 ≦ NI / NP ≦ 0.9 [7]
(In Formula [7],
NI represents the nitrogen content (% by weight) of the nitrogen-containing alloy,
NP represents the nitrogen content (% by weight) of the phosphor to be produced. )

  Here, the above formula [7] represents the degree of nitridation of the nitrogen-containing alloy with respect to the nitrogen-containing alloy based on the nitrogen content of the phosphor produced by the secondary nitriding step described later. Naturally, the nitrogen content of the nitrogen-containing alloy after the completion of the primary nitriding step is smaller than the nitrogen content of the phosphor. The value of the above formula [7] is arbitrary as long as the phosphor of the present invention is obtained, but is usually 0.03 or more, preferably 0.04 or more, more preferably 0.05 or more, and still more preferably 0.1. Above, especially preferably 0.15 or more, and usually 0.9 or less, preferably 0.85 or less.

  If the value of NI / NP in the above formula [7] is smaller than the above range, the nitriding may not progress sufficiently in the primary nitriding step, the heat generation rate in the secondary nitriding step may be increased, and the characteristics are high. There is a tendency that a phosphor is difficult to obtain. On the other hand, if the value of NI / NP in the above formula [7] is larger than the above range, the nitrogen-containing alloy itself tends to be unstable and difficult to handle.

In order to make the secondary nitriding process proceed smoothly, depending on the reactivity of the alloy as a raw material, the degree of progress of nitriding of the nitrogen-containing alloy as expressed by the above formulas [5], [6], [7], for example, It is preferable to adjust appropriately. Here, the reactivity of the alloy as a raw material is determined by the composition, the weight median diameter D _{50, and the} like. For example, when or if the weight-average median diameter D ₅₀ containing Sr small high reactivity of the raw material and nitrogen. Therefore, when a highly reactive material is used, it is preferable to increase the degree of nitriding in the primary nitriding step. Conversely, when a less reactive material is used, the degree of nitriding in the primary nitriding step. Is preferably kept low.

  Moreover, the reactivity with respect to nitrogen of the alloy powder which consists of a phosphor raw material alloy obtained by the grinding | pulverization process can be estimated by performing TG-DTA measurement of this alloy powder in nitrogen stream. Specifically, the alloy powder and nitrogen are reacted under atmospheric pressure in the temperature range from 100 ° C. to 1500 ° C. from the melting point of the phosphor raw material alloy, and the weight of the alloy powder is measured by TG-DTA measurement. And determine the rate of weight increase.

  At this time, there is no particular problem when the continuous method is used, but when the batch method is used, the rate of weight increase of the alloy powder is usually 5% by weight / hour or more, particularly 10% by weight / hour or more, and usually 300%. It is preferable to select the nitrogen concentration in the atmosphere of the primary nitriding step so that it is not more than wt% / hour, particularly not more than 150 wt% / hour, particularly not more than 100 wt% / hour (however, the temperature rising rate is 10%). ℃ / min). When the batch method is used, if a nitrogen concentration is selected such that the rate of weight increase is greater than the above range, the heat generation tends to be too large in the primary nitriding process, and the heat generated when producing a large amount of nitrogen-containing alloy is caused. In some cases, the alloy material may be melted or phase-separated, or nitride may be decomposed to deteriorate the characteristics of the phosphor. On the other hand, if a nitrogen concentration is selected such that the rate of weight increase is smaller than the above range, productivity may decrease or the luminance of the phosphor may decrease due to reasons such as insufficient nitriding reaction. is there.

The oxygen content of the nitrogen-containing alloy can be determined by, for example, measuring the oxygen content with an oxygen-nitrogen simultaneous analyzer (manufactured by Leco) and using the following formula [8].
Oxygen content of nitrogen-containing alloy (wt%)
= (Oxygen content / weight of nitrogen-containing alloy) x 100 ... [8]

  The oxygen content (% by weight) of the nitrogen-containing alloy is arbitrary as long as the phosphor of the present invention is obtained, but is usually 7.5% by weight or less, preferably 5% by weight or less, and usually 0.1% by weight. That's it. If the oxygen content is too high, the brightness of the phosphor obtained may be lowered.

  The nitrogen-containing alloy as described above is further nitrided by the secondary nitriding process, or the alloy powder of the nitrogen-containing alloy and the alloy powder (alloy powder before primary nitriding) obtained by the pulverizing process are mixed. The phosphor of the present invention can be obtained by further nitriding by the secondary nitriding step. At this time, since the heat generation rate in the secondary nitriding step can be controlled, it becomes possible to mass-produce phosphors made of alloys.

The weight-average median diameter D ₅₀ of the alloy powder of the secondary nitriding process prior to the nitrogen-containing alloy, it is preferable to adjust the particle size by the activity of the metal elements constituting the alloy. The specific range is not limited as long as the phosphor of the present invention is obtained, but usually the same range as the alloy powder of the phosphor raw material alloy (alloy powder before the primary nitriding step) is preferable.

(Cooling and grinding)
When the primary nitriding process is performed, the alloy powder made of the nitrogen-containing alloy obtained in the primary nitriding process may be once cooled after the primary nitriding process and before the secondary nitriding process (cooling process).

  When the apparatus used in the primary nitriding process is different from the apparatus used in the secondary nitriding process, the alloy powder is usually cooled to a temperature of 200 ° C. or lower and then taken out and charged into the apparatus used in the secondary nitriding process. Further, even when the apparatus used in the primary nitriding step and the apparatus used in the secondary nitriding step are the same, it is preferable to cool once before switching or replacing the atmosphere in the device. Without cooling, there is a possibility that the temperature of the alloy powder rapidly rises due to a sudden change in nitrogen partial pressure and melts, or the alloy powder changes in quality when it comes into contact with the atmosphere at a high temperature. The cooling temperature in this case is usually a temperature that is 100 ° C. or more lower than the melting point of the nitrogen-containing alloy, preferably 200 ° C. or more that is lower than the melting point of the nitrogen-containing alloy. It is.

After cooling, pulverization and / or mixing is performed as necessary. The weight median diameter D ₅₀ of the alloy powder made of the nitrogen-containing alloy after pulverization is usually 100 μm or less, and is preferably the same as the alloy powder before the primary nitriding step.

The nitrogen-containing alloy after the primary nitriding process has a higher limit oxygen concentration and is less prone to dust explosion than the alloy powder before the primary nitriding process in the same particle size range, so handling and safety are more It has improved. However, since the nitrogen-containing alloy after the primary nitriding process may be hydrolyzed in the atmosphere or oxidized and mixed with oxygen, it is handled in dry air, nitrogen atmosphere, or inert gas atmosphere such as argon. It is particularly preferable to handle in a nitrogen atmosphere. In addition, an inert gas may use only 1 type and may use 2 or more types together by arbitrary combinations and a ratio.
The oxygen concentration in the atmosphere is usually 5% by volume or less, preferably 4% by volume or less, and usually 0.1 ppm or more. If the oxygen concentration is too high, it may be oxidized, so be careful.
When such a primary nitriding step is introduced, the reactivity of the raw material alloy and nitrogen in the secondary nitriding step described later can be controlled. Although it depends on other conditions, the amount of the phosphor that can be manufactured at one time can be increased by 1.5 times or more, preferably by 2 times or more, compared with the case where the primary nitriding step is not performed.

<Secondary nitriding process (nitriding process)>
In the secondary nitriding step, the phosphor material is obtained by nitriding the phosphor material. At this time, the phosphor raw material may be an alloy for phosphor raw material (preferably an alloy powder thereof) that has not undergone the primary nitriding step, and a nitrogen-containing alloy (preferably the alloy thereof) obtained by the primary nitriding step. Powder) may be used, or both may be used in combination. However, from the viewpoint of industrial productivity, it is preferable to perform nitriding treatment only on the alloy powder of the nitrogen-containing alloy or on the mixture of the alloy powder of the phosphor raw material alloy and the alloy powder of the nitrogen-containing alloy. Further, when the mixture is subjected to nitriding treatment, the ratio of the nitrogen-containing alloy powder in the mixture is preferably 20% by weight or more. Moreover, it is preferable that it is a nitrogen-containing alloy whose total metal element content rate is 97 weight% or less (it corresponds to said 1). In particular, a part or all of the phosphor raw material alloy is preferably a nitrogen-containing alloy having a nitrogen content of 10% by weight or more. This is because if the amount of the nitrogen-containing alloy or the nitrogen content of the nitrogen-containing alloy is too small, the advantage of performing the primary nitriding step may not be sufficiently obtained.

  The nitriding treatment in the secondary nitriding step is performed by filling the phosphor material into a firing 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 firing container. Although the material of the baking container used here is arbitrary as long as the effect of the manufacturing method of this invention is acquired, boron nitride, silicon nitride, carbon, aluminum nitride, tungsten etc. are mentioned, for example. Of these, boron nitride is preferable because of its 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 baking 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 firing container may be a round shape, an elliptical shape such as an ellipse, or a polygonal shape such as a triangle or a quadrangle. The height of the firing container is arbitrary as long as it enters the heating furnace, and is low. But it can be expensive. Among these, it is preferable to select a shape with good heat dissipation.

The firing container filled with the phosphor material is placed in a firing apparatus (sometimes referred to as a “heating furnace”). The firing apparatus used here is arbitrary as long as the effect of the production method of the present invention can be obtained, but an apparatus capable of controlling the atmosphere in the apparatus is preferable, and an apparatus capable of controlling the pressure is also preferable. For example, a hot isostatic press (HIP), a resistance heating vacuum pressurizing atmosphere heat treatment furnace, and the like are preferable.
Further, it is preferable to circulate a gas containing nitrogen in the baking apparatus and sufficiently replace the inside of the system with this nitrogen-containing gas before the start of heating. If necessary, a nitrogen-containing gas may be circulated after the system is evacuated.

  Examples of the nitrogen-containing gas used in the nitriding 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, high light emission cannot be obtained. Therefore, the lower the oxygen concentration in the nitriding atmosphere, the more preferable it is, usually 0.1 Volume% or less, preferably 100 ppm or less, more preferably 10 ppm or less. Further, if necessary, an oxygen getter such as carbon or molybdenum 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.

  The nitriding treatment is performed by heating the phosphor raw material in a state filled with nitrogen gas or in a state in which it is circulated, and the pressure at that time is somewhat reduced from atmospheric pressure, atmospheric pressure or pressurized state. But it ’s okay. However, in order to prevent oxygen from being mixed in the atmosphere, the pressure is preferably set to atmospheric pressure or higher. If the pressure is less than atmospheric pressure, if the heating furnace is not hermetically sealed, a large amount of oxygen may be mixed and a high-quality phosphor may not be obtained. The pressure of the nitrogen-containing gas is preferably at least a gauge pressure of 0.2 MPa or more, more preferably 10 MPa or more, and preferably 200 MPa or less.

  The heating temperature of the phosphor raw material is arbitrary as long as the phosphor of the present invention is obtained, but is usually 800 ° C. or higher, preferably 1000 ° C. or higher, more preferably 1200 ° C. or higher, and usually 2200 ° C. or lower, preferably 2100 ° C. Hereinafter, it is more preferably 2000 ° C. or lower. When the heating temperature is lower than 800 ° C., the time required for the nitriding treatment may become very long. On the other hand, when the heating temperature is higher than 2200 ° C., the generated nitride is volatilized or decomposed, the chemical composition of the obtained nitride phosphor shifts, and a phosphor with high characteristics cannot be obtained, and the reproducibility is also poor. It can be a thing.

  The heating temperature varies depending on the alloy composition and the like, but is usually 300 ° C. or higher, particularly 400 ° C. or higher, more preferably 500 ° C. or higher, particularly 700 ° C. or higher than the melting point of the phosphor raw material alloy. preferable. Note that the melting point of the alloy is as described in the section of the primary nitriding step.

The heating time (holding time at the maximum temperature) during the nitriding 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 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.
Thus, the phosphor of the present invention having a nitride or oxynitride as a base can be obtained by nitriding the phosphor material.

  By the way, in the secondary nitriding step, when a nitriding treatment is performed on a large amount of phosphor raw material at a time, depending on other conditions, the nitriding reaction may proceed rapidly, which may deteriorate the characteristics of the phosphor of the present invention. is there. Thus, when heat treatment of a large amount of phosphor raw material is desired at a time, it is preferable to adjust the temperature raising conditions as follows, since the rapid progress of the nitriding reaction can be further suppressed.

  That is, in the secondary nitriding step, a temperature range from a temperature 100 ° C. lower than the melting point of the phosphor raw material alloy to be heated to a temperature 30 ° C. lower than the melting point (hereinafter referred to as “temperature range in which the heating rate is reduced”) Is heated at a rate of temperature increase of 9 ° C./min or less. Thus, the reason for decelerating the temperature increase rate in the temperature range from a temperature 100 ° C. lower than the melting point of the alloy to be heated to a temperature 30 ° C. lower than the melting point is as follows. However, even when a nitrogen-containing alloy is used instead of the phosphor raw material alloy or when a phosphor raw material alloy and a nitrogen-containing alloy are used in combination, the above-mentioned “melting point of the phosphor raw material alloy to be heated” Is the melting point of the phosphor raw material alloy.

The phosphor is generally synthesized by filling a phosphor raw material into a firing container such as a crucible or a tray and heating it in a heating furnace. At this time, productivity can be increased by shortening the residence time of the phosphor raw material in the furnace. Therefore, the rate of temperature rise to the temperature range required for the reaction depends on the capacity of the heating furnace and the heat resistance of the crucible and the like. It is preferable that the speed is as fast as the impact characteristics allow.
However, when producing phosphors industrially using alloys such as phosphor raw material alloys and nitrogen-containing alloys as raw materials, if the temperature rise rate is high, the alloy powder melts due to the heat generated during nitriding, and the alloy particles In some cases, nitrogen gas cannot penetrate into the inside of the alloy particles and the nitriding reaction does not proceed to the inside of the alloy particles. For this reason, the brightness | luminance of the fluorescent substance obtained tends to fall and depending on the case, it may not light-emit.

When the diameter of the firing container is the same, if the filling amount of the alloy powder is small, the heat dissipation is high and the amount of heat generated during the nitriding reaction is small, so the above-mentioned phenomenon does not occur. However, if the filling amount of the phosphor raw material is large, the heat dissipation performance is lowered, so that it is desired to suppress the heat generation during the nitriding reaction.
On the other hand, the synthesis of phosphors, particularly nitride phosphors, usually involves the use of an expensive reactor because the reaction is carried out under high temperature and pressure. Therefore, increasing the filling amount of the phosphor raw material per time is desired for reducing the cost.

  Therefore, in the method for producing a phosphor according to the present invention, it is preferable to reduce the rate of temperature rise in a specific temperature range described later (corresponding to 2). Thereby, even when the phosphor is industrially produced using an alloy such as a phosphor raw material alloy or a nitrogen-containing alloy as a raw material, it is possible to avoid a decrease in phosphor characteristics due to accumulation of reaction heat. In particular, when the phosphor raw material alloy contains Sr, the nitriding reaction may proceed rapidly between the melting point of the phosphor raw material alloy and the melting point, and the weight of the raw material may increase rapidly. However, if the rate of temperature rise is decelerated in this temperature range, there is an effect that this rapid weight increase does not occur.

The temperature range in which the rate of temperature increase is reduced is usually a temperature range from a temperature 100 ° C. lower than the melting point of the phosphor raw material alloy to a temperature 30 ° C. lower than the melting point, preferably the melting point of the phosphor raw material alloy. It is a temperature range from a temperature lower than 150 ° C. or higher, more preferably a temperature higher than 200 ° C. lower than the melting point, preferably a temperature lower than the melting point, more preferably a temperature higher than the melting point to 100 ° C. or higher.
Here, the temperature lower by 100 ° C. than the melting point of the phosphor raw material alloy roughly means a temperature at which nitriding is started. In addition, since the nitriding reaction proceeds rapidly in the temperature range from a temperature 30 ° C. lower than the melting point to the melting point, it is often difficult to control the progress of the nitriding reaction by the heating rate.
Note that the temperature in the temperature range from 100 ° C. lower than the melting point to 30 ° C. lower than the melting point refers to the temperature in the furnace during the heat treatment, that is, the set temperature of the baking apparatus.

  In the temperature range where the temperature increase rate is decelerated, the temperature increase rate is usually 9 ° C./min or less, preferably 7 ° C./min or less. If the heating rate is higher than this, a rapid accumulation of reaction heat cannot be avoided, and a phosphor with high brightness tends not to be obtained. The lower limit of the rate of temperature rise is not particularly limited, but is usually 0.1 ° C./min or more, preferably 0.5 ° C./min or more from the viewpoint of productivity.

  In addition, there is no restriction | limiting in particular about the temperature rising conditions in the temperature range lower than the temperature lower 100 degreeC than melting | fusing point of the alloy for fluorescent material raw materials, You may heat up rapidly or slowly. In consideration of the responsiveness of the temperature control of the heating furnace, the temperature increase rate may be reduced to 9 ° C./min or less from a temperature lower than 100 ° C. lower than the melting point of the alloy.

  Further, when heating is continued even after reaching a temperature 30 ° C. lower than the melting point of the phosphor raw material alloy, the rate of temperature rise is not particularly limited, but in the temperature range from the temperature 30 ° C. lower than the melting point to the melting point However, it is preferable to increase the temperature slowly at a rate of usually 9 ° C./min or less, particularly 7 ° C./min or less, usually 0.1 ° C./min or more, particularly 0.5 ° C./min or more. Even in the case of heating to a temperature higher than the melting point, the rate of temperature increase from the melting point to the temperature is usually 9 ° C./min or less, particularly 7 ° C./min or less, usually 0.1 ° C./min. As described above, it is particularly preferably 0.5 ° C./min or more. However, in the high temperature range from 10 ° C. higher than the melting point, there is no particular effect by reducing the temperature rising rate. It is preferable to increase the productivity by increasing the temperature rising rate at 10 ° C./min or more, for example, 10 ° C./min to 100 ° C./min.

The melting point of the phosphor raw material alloy is the same as described in the section of the primary nitriding step.
As described above, the phosphor of the present invention can be manufactured by nitriding the phosphor raw material alloy and / or the nitrogen-containing alloy.

[III] Other additional processes
{Reheating process}
The phosphor obtained by the secondary nitriding step may be subjected to a reheating step as necessary, and may be subjected to heat treatment (reheating 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 1200 ° C. or higher, preferably 1300 ° C. or higher, more preferably 1400 ° C. or higher, particularly preferably 1500 ° C. or higher, and usually 2200 ° C. or lower, preferably 2100 ° C. or lower. More preferably, it is 2000 degrees C or less, Most preferably, it is 1900 degrees C or less. When heated below 1200 ° C., the effect of growing phosphor particles tends to be reduced. On the other hand, heating at a temperature exceeding 2200 ° C. not only consumes unnecessary heating energy, but also may cause the phosphor to decompose. 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 gas atmosphere, an inert gas atmosphere or a reducing 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 sealing property of the baking apparatus is poor as in the heating step described above, and a phosphor with 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.

<Dispersing process>
In the dispersion process, a mechanical force is applied to the phosphor that has been aggregated due to particle growth, sintering, and the like during the nitriding process, 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 coarsely pulverized with, for example, a jaw crusher, a stamp mill, a hammer mill, etc., and then washed with a neutral or acidic solution (hereinafter sometimes referred to as “cleaning medium”).
As a neutral solution used here, it is preferable to use water. The type of water that can be used is not particularly limited, but demineralized water or distilled water is preferred. The electric conductivity of the water used is usually 0.0064 mS / m or more, usually 1 mS / m or less, preferably 0.5 mS / m or less. The temperature of water is usually preferably room temperature (about 25 ° C.), preferably 40 ° C. or higher, more preferably 50 ° C. or higher, preferably 90 ° C. or lower, more preferably 80 ° C. or lower. By using water, it is possible to reduce the number of times of washing for obtaining the target phosphor.

  An acidic aqueous solution is preferable as the acidic solution. Although there is no restriction | limiting in particular in the kind of acidic aqueous solution, The aqueous solution which diluted 1 type, or 2 or more types of mineral acids, such as hydrochloric acid and a sulfuric acid, can be used. The acid concentration of the acid aqueous solution is usually 0.1 mol / l or more, preferably 0.2 mol / l or more, and usually 5 mol / l or less, preferably 2 mol / l or less. When an acidic aqueous solution is used instead of a neutral aqueous solution, it is preferable in terms of the efficiency of reducing the amount of dissolved ions of the phosphor, but when the acid concentration of the acid aqueous solution used for this cleaning exceeds 5 mol / l, the phosphor surface is removed. May dissolve. On the other hand, when the acid concentration of the acidic solution is less than 0.1 mol / l, the effect using the acid tends not to be sufficiently obtained.

In the present invention, a highly corrosive acid such as hydrofluoric acid is not required as the acidic solution used for cleaning.
Moreover, only 1 type may be used for a washing | cleaning medium, and 2 or more types may be performed by arbitrary combinations and a ratio.

  The method for washing the phosphor is not particularly limited. Specifically, the obtained phosphor particles are dispersed in the neutral or acidic solution (washing medium) described above and stirred for a predetermined time. Thereafter, a method of solid-liquid separation of the phosphor particles is exemplified.

  There is no particular limitation on the stirring method for cleaning the phosphor, and it is sufficient that the phosphor particles can be uniformly dispersed. For example, a chip stirrer or a stirrer can be used.

The amount of the cleaning medium is not particularly limited, but if it is too small, sufficient cleaning effect cannot be obtained, and if it is excessively large, a large amount of cleaning medium is required, which is unreasonable. 2 times or more, preferably 5 times or more, and 1000 times or less, preferably 100 times or less the weight of the phosphor to be cleaned.
The stirring time may be a time that can sufficiently bring the phosphor and the above-described cleaning medium into contact, and is usually 1 minute or longer and usually 1 hour or shorter.

  There is no restriction | limiting in particular in the method of solid-liquid-separating a washing | cleaning medium and fluorescent substance particle, For example, filtration, centrifugation, a decantation etc. are mentioned.

  However, the method for cleaning the phosphor particles is not limited to the above-described method of stirring and dispersing the phosphor particles in a cleaning medium and performing solid-liquid separation after the dispersion. A method of exposing to a fluid of a cleaning medium may be used.

Moreover, you may perform such a washing | cleaning process in multiple times. When performing multiple washing steps, washing with water and washing with an acidic solution may be performed in combination, but in that case, washing with an acidic solution is performed in order to prevent acid from adhering to the phosphor. Thereafter, it is preferable to perform washing with water. Further, after washing with water, washing with an acidic solution may be performed, followed by washing with water.
Moreover, when performing the washing | cleaning process in multiple times, you may perform the above-mentioned crushing process and classification process between washing | cleaning processes.

It is preferable that the phosphor is washed until the electrical conductivity of the supernatant at that time is less than or equal to a predetermined value by performing the following water dispersion test on the phosphor after washing.
That is, the washed phosphor is pulverized or pulverized by a dry ball mill or the like as necessary, classified by a sieve or a water tank, and sized to a desired weight median diameter, and then 10 wt. The phosphor particles having a specific gravity heavier than that of water are naturally precipitated by stirring and dispersing in double water for a predetermined time, for example, 10 minutes, and then allowing to stand for 1 hour. The electrical conductivity of the supernatant liquid at this time is measured, and the above-described washing is performed as necessary until the electrical conductivity is usually 50 mS / m or less, preferably 10 mS / m or less, more preferably 5 mS / m or less. Repeat the operation.

  The water used for the water dispersion test of the phosphor is not particularly limited, but desalted water or distilled water is preferable in the same manner as the above-mentioned cleaning medium water, and the electrical conductivity is usually usually 0.0064 mS / m or more. Moreover, it is 1 mS / m or less normally, Preferably it is 0.5 mS / m or less. The temperature of the water used for the water dispersion test of the phosphor is usually room temperature (about 25 ° C.).

  By performing such cleaning, the luminance of the phosphor can be further improved.

  The electrical conductivity of the supernatant liquid in the phosphor aqueous dispersion test can be measured using an electrical conductivity meter “EC METER CM-30G” manufactured by Toa Decay Inc.

  The electrical conductivity of the supernatant liquid in the phosphor aqueous dispersion test increases as a result of dissolution of some of the constituent components of the phosphor into ions as a result of dissolution. That the electrical conductivity of the supernatant liquid is low means that the content of the water-soluble component in the phosphor is small.

  Further, the oxygen content of the phosphor may be reduced by performing the cleaning process. This is presumably because an impurity phase containing oxygen, for example, a hydroxide generated by hydrolysis of a nitride having poor crystallinity is removed.

For example, in the phosphor of the present invention, it can be assumed that the following occurs when washed.
(1) Nitride or the like having poor crystallinity is hydrolyzed to form a hydroxide such as Sr (OH) ₂ and dissolves in water. When washed with warm water or dilute acid, they are efficiently removed and the electrical conductivity is lowered. On the other hand, if the acid concentration of the cleaning medium is too high or the exposure time to the acidic solution is too long, the host phosphor itself may be decomposed.
(2) Boron mixed from the boron nitride (BN) crucible used during heating in the heating step forms a water-soluble boron nitrogen-alkaline earth compound and mixes into the phosphor. Decomposed and removed.

  The reason for the improvement in luminous efficiency and brightness by washing is not completely clear, but since a slight ammonia odor is felt when the phosphor immediately after firing is taken out into the air, this unreacted or This is considered to be due to the removal of the part produced by decomposition of the part with insufficient reaction.

<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.

[IV] Manufacture of Alloys by Atomizing Method etc. By the way, the phosphor raw material alloy and the nitrogen-containing alloy are manufactured by the above-described method, and may be manufactured through the steps (a) to (c) described below. it can. Thereby, an alloy powder for phosphor raw material having an angle of repose of 45 degrees or less can be obtained (corresponding to 4).
(A) Among the materials of the metals Ln, Ca, Sr, M ^II , M ^III and M ^IV constituting the phosphor,
Two or more kinds are melted to prepare a molten alloy containing these elements (melting step).
(B) The molten alloy is refined in an inert gas (a refinement process).
(C) The refined molten alloy is solidified to obtain an alloy powder (solidification step).

  That is, in this method, the molten alloy is refined in gas and solidified to obtain a powder. The (b) refinement step and (c) solidification step are preferably pulverized by, for example, a method of spraying molten alloy, a method of quenching by a roll or a gas flow, and making a ribbon shape, an atomizing method, or the like. In particular, it is preferable to use the atomizing method.

The atomizing method refers to a method in which a liquid is dropped or blown out with a nozzle, pulverized with a jet fluid to form droplets, and solidified into powder. Examples of the atomizing method include a water atomizing method, a gas atomizing method, and a centrifugal force atomizing method. Among them, the gas atomization method is particularly preferable because it contains less impurities such as oxygen and the resulting alloy powder is spherical. In the present invention, the leviatomization method can also be used. The leviatomization method is a combination of a gas atomization method and levitation dissolution. When this method is used, contact between the crucible and the raw material can be avoided.

  First, in order to produce the phosphor raw material alloy, the metal or alloy as the raw material is weighed in the same manner as described in {Weighing raw materials}. Then, in the same manner as described in {melting of raw material}, the raw material is melted and alloyed to prepare a molten alloy of phosphor raw material alloy.

The obtained molten alloy is then subjected to (b) a refinement process. At this time, the molten alloy may be directly subjected to the (b) refinement process, and the molten alloy is once cooled and cast to obtain an ingot of the alloy, which is then melted again ( b) You may use for a refinement | miniaturization process.
Further, (b) the miniaturization step and (c) the solidification step may be performed in one step. In particular, with the gas atomization method, these steps can be easily performed in one step.

Hereinafter, the gas atomizing method will be described as an example.
FIG. 4 illustrates a schematic diagram of an alloy powdering apparatus using a gas atomizing method. In the apparatus shown in FIG. 4, in a melting chamber 101 provided with an induction coil 102, a metal and / or alloy as a raw material (as described above, a raw metal is melted to prepare a molten alloy, which is directly powdered by a gas atomization method. The molten alloy is once solidified, cast, and then melted. In the following description of the atomizing method, these are simply referred to as “raw material alloys”). The molten alloy is poured from a narrow hole provided at the bottom of the crucible 103 in the melting chamber 101 to create a flow of molten metal or droplets. A jet stream of pulverized gas is blown from the jet nozzle 104 to the molten metal that has flowed out, and the molten metal flowing down is sequentially refined by the energy of the jet stream of the pulverized gas, and the generated fine droplets are injected into the jet chamber 105. To solidify the alloy powder. Normally, coarse particles of the obtained alloy powder are directly collected in the collection chamber 106, and fine particles are collected in the cyclone 107. Note that a molten metal receptacle for removing uncrushed molten metal can also be provided in the injection chamber 105.

The pressure of the dissolution chamber 101 is arbitrary as long as the phosphor of the present invention can be produced, but is usually 1 × 10 ³ Pa or more and usually 1 × 10 ⁵ Pa or less, and from the viewpoint of safety, it is less than atmospheric pressure. More preferably. Further, the atmosphere of the melting chamber 101 is preferably an inert gas atmosphere in order to prevent metal oxidation. Examples of the inert gas include rare gas elements such as helium, neon, and argon. Among them, argon is preferable. In addition, 1 type of inert gas may be used independently, and 2 or more types may be used together by arbitrary combinations and a ratio.

  The material of the crucible 103 is arbitrary as long as the phosphor of the present invention can be manufactured. For example, aluminum oxide, calcium oxide, magnesium oxide, graphite, boron nitride and the like can be used, and contamination of impurities can be avoided. Aluminum oxide or boron nitride is preferred. In addition, the raw material of the crucible 103 may use 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  Although there is no restriction | limiting in the melting method of a raw material alloy, It is preferable to melt | dissolve by the high frequency melting method similarly to the melting | fusing process of above-mentioned {melting | fusing of raw materials}. The molten metal in the crucible 103 is supplied with electric power to the high-frequency induction coil 102, so that the melting point is higher than the freezing point of the alloy or metal used as a raw material, preferably 1450 ° C. or higher, more preferably 1480 ° C. or higher, and usually 1800 ° C. or lower, preferably Is kept at 1700 ° C. or lower, more preferably 1600 ° C. or lower.

  For the injection nozzle 104, ceramics with high heat resistance are usually used, and among these, aluminum oxide, calcium oxide, and boron nitride are preferable. The inner diameter of the nozzle is appropriately selected depending on the viscosity of the molten metal and the like, but is usually 0.5 mm or more, preferably 1 mm or more, and usually 5 mm or less, preferably 3 mm or less.

  The pulverizing gas is preferably an inert gas because it directly collides with the molten alloy. Among the inert gases, a rare gas such as nitrogen or argon is preferable. In addition, 1 type of inert gas may be used independently, and 2 or more types may be used together by arbitrary combinations and a ratio.

Although there is no restriction | limiting in the temperature of a grinding gas, Usually, it is room temperature.
Further, the injection pressure of the pulverization gas is arbitrary as long as an alloy powder having a desired particle diameter can be obtained, but is usually 10 kg / cm ² (0.98 MPa) or more, preferably 20 kg / cm ² (1.96 MPa) or more, usually It is 100 kg / cm ² (9.8 MPa) or less and 80 kg / cm ² (7.84 MPa) or less. When the injection pressure is out of this range, the yield tends to decrease.

The atmosphere of the injection chamber 105 and the recovery chamber 106 is preferably an inert gas atmosphere or a nitrogen atmosphere, and more preferably a nitrogen atmosphere or a nitrogen-containing inert gas atmosphere for economic reasons.
The nitrogen concentration in the ejection chamber 105 and the recovery chamber 106 is arbitrary as long as the phosphor of the present invention can be produced, but is usually 0.1% or more, preferably 10% or more, more preferably 20% or more, and usually 100. % Or less. If the nitrogen concentration is too low, a highly volatile metal component may volatilize from the particle surface during the pulverization process and the alloy powder recovery process, and the surface composition may shift.

  The pressure in the injection chamber 105 and the recovery chamber 106 is usually near atmospheric pressure, and the temperature of the injection chamber 105 and the recovery chamber 106 is not particularly limited as long as it is equal to or lower than the melting point of the phosphor raw material alloy. The temperature of the injection chamber 105 is usually 950 ° C. or lower and 0 ° C. or higher. The temperature of the recovery chamber 106 is usually 0 ° C. or higher, preferably 20 ° C. or higher, and usually 400 ° C. or lower, and preferably 40 ° C. or lower.

  (C) In the solidification step, it is preferable to rapidly cool the molten alloy droplet generated by the jet fluid. Rapid cooling refers to an operation of cooling more rapidly than a high temperature. The time required for the molten alloy droplets to solidify is arbitrary as long as the phosphor of the present invention can be produced, but is usually 1 minute or less, preferably 30 seconds or less, more preferably 10 seconds or less, and still more preferably. 3 seconds or less. In the gas atomization method described above, an alloy powder is produced by pulverization by colliding a pulverized gas against a molten metal dropped through a narrow hole. At this time, from the moment of being pulverized into fine particles, it is rapidly cooled by the thermal spray from the surface and the pulverized gas, and since the surface area through which heat is dissipated is large relative to the volume, rapid solidification is possible, which is preferable.

  In the gas atomization method, while controlling the pulverization gas and / or the nitrogen concentration in the atmosphere of the injection chamber 105 and the recovery chamber 106 in the above-described (b) miniaturization step and (c) solidification step, the alloy powder is produced. At the same time, the above-described primary nitriding process can be advanced to produce a nitrogen-containing alloy. In this case, for example, the following i) is preferable, and the following i) and ii) are more preferable.

  i) At least one of the pulverized gas, the injection chamber 105 and the recovery chamber 106 is set to a high concentration nitrogen-containing atmosphere. The nitrogen concentration at this time is preferably close to 100% by volume, usually 90% by volume or more, preferably 95% by volume or more, and more preferably 98% by volume or more.

  ii) Although the temperature at the bottom of the injection nozzle 104 and the crucible 103 varies depending on the melting point of the alloy, it is usually 900 ° C. or higher, preferably 1000 ° C. or higher, and usually 1300 ° C. or lower, preferably 1200 ° C. or lower. In this case, for example, heating may be performed by a high frequency melting method, or the temperature may be designed to be the above-described temperature by heat conduction from the melting chamber 101.

The alloy powder thus produced is subjected to a classification treatment as necessary and used in the above-described primary nitriding step and / or secondary nitriding step. For example, the above-mentioned desired weight median diameter D ₅₀ and particle size distribution are adjusted using a sieving device using a mesh such as a vibratory screen, a shifter, an inertia classifier such as an air separator, or a centrifuge such as a cyclone. The

  This classification step is also preferably performed in an inert gas atmosphere, and the oxygen concentration in the inert gas atmosphere is preferably 10% or less, particularly preferably 5% or less. Although there is no restriction | limiting in particular in the kind of inert gas, Usually, 1 type (s) or 2 or more types, such as nitrogen, argon, helium, are used, and nitrogen is especially preferable from a viewpoint of economical efficiency.

  As described above, it can be obtained as an alloy powder formed of the phosphor raw material alloy or the nitrogen-containing alloy also by the atomizing method described above. In particular, according to this method, (a) by pulverizing the molten alloy obtained in the melting step, it is possible to carry out a consistent process from the raw metal to the production of the alloy powder and further the nitrogen-containing alloy. . Furthermore, a phosphor is produced from the raw material metal by providing transfer means (pipeline, belt conveyor, etc.) for transferring the obtained alloy powder and / or nitrogen-containing alloy to a firing apparatus used in the secondary nitriding step. It is also possible to carry out the process consistently.

[V] Properties of Alloy Powders Produced by Atomizing Method etc. Alloy powders produced by the atomizing method etc. described in [IV] above (alloy powders made of phosphor raw material alloy or nitrogen-containing alloy) are preferably Has the following characteristics.

(Liquidity)
There are an angle of repose, a collapse angle, and a difference angle as indicators of fluidity. These measurements are described in Carr et al., Chemical Engineering, Jan. 18, (1965) 166-167, and can be measured using, for example, a powder tester PT-N type (manufactured by Hosokawa Micron Corporation).

The angle of repose refers to an angle formed between the generatrix of the cone and a horizontal plane when the granular material is gently dropped from a funnel or the like into a flat shape and deposited in a conical shape.
When the alloy powder for a phosphor material used in the present invention is manufactured by the above-described atomizing method or the like, the angle of repose usually corresponds to 45 degrees or less (said 4). ), Preferably 40 degrees or less, more preferably 35 degrees or less, and the smaller the better. This is because the smaller the angle of repose, the higher the fluidity and the better the handleability when operating industrially. On the other hand, if the angle of repose is too large, the fluidity is low and transportation and transportation tend to be difficult.

The collapse angle is the angle of the mountain that remains after a certain impact is applied to the granular material that forms the angle of repose.
When the phosphor raw material alloy powder used in the present invention is produced by the above-described atomizing method or the like, the collapse angle is usually 25 degrees or less, preferably 20 degrees or less, more preferably 15 degrees or less, Smaller is preferable.

The angle obtained by subtracting the collapse angle from the angle of repose is called the difference angle.
When the alloy powder for a phosphor raw material used in the present invention is manufactured by the above-described atomizing method or the like, the difference angle is preferably 20 degrees or less. If the difference angle is too large, a flushing phenomenon is likely to occur and control tends to be difficult, which is not preferable.

  When an alloy powder having a small angle of repose, collapse angle, difference angle and high fluidity is used as a raw material, the handling property is improved, and the effect of facilitating transportation and transportation can be obtained.

(shape)
When the phosphor raw material alloy powder used in the present invention is manufactured by the above-described atomizing method or the like, the average circularity can be used as an index for quantitatively expressing the spherical nature of the alloy particles. .
Here, the average circularity is obtained by the following equation, and represents the degree of approximation of each particle size with a perfect circle in the projected view of particles.
Average circularity = Perimeter length of a perfect circle equal to the projected area of the particle / Perimeter length of the projected image of the particle

When the phosphor raw material alloy powder used in the present invention is produced by the above-described atomizing method, the average circularity is usually 0.7 or more, preferably 0.8 or more, more preferably 0.9. As described above, the closer to 1, the more preferable.
In addition, when the phosphor raw material alloy powder used in the present invention is manufactured by the above-described atomization method or the like, the number ratio of true spherical alloy particles having an average circularity of 0.9 or more is usually 20%. % Or more, preferably 40% or more.

(Weight median diameter D ₅₀ )
When the phosphor raw material alloy powder used in the present invention is manufactured by the above-described atomizing method or the like, the weight median diameter D ₅₀ needs to be adjusted by the activity of the metal element constituting the alloy powder. In a normal case, it is 0.1 μm or more, preferably 1 μm or more, more preferably 3 μm or more, and 100 μm or less, preferably 50 μm or less, more preferably 30 μm or less. In the case of containing Sr has a high reactivity with the ambient gas, the weight median diameter D ₅₀ of the alloy powder, usually 5μm or more, preferably 8μm or more, and more preferably 10μm or more, particularly preferably 13μm or more It is desirable to do.
If the weight median diameter D ₅₀ is smaller than the above range, the rate of heat generation during a reaction such as nitriding increases, which may make it difficult to control the reaction. On the other hand, if the weight median diameter D ₅₀ is larger than the above range, the reaction such as nitriding inside the alloy particles may be insufficient, and the luminance may decrease.

(Tap density)
The tap density refers to the density when a certain vibration (tapping) is applied. That is, in this specification, the tap density is a value obtained by measuring as follows.
About 10 g of alloy powder is put into a glass graduated cylinder with a capacity of 10 ml, and the volume does not change at intervals of about 50 times / minute to 500 times / minute from the position of about 1 cm to 5 cm in height (usually normal) After manual tapping (200 to 800 times), the volume (V) of the alloy powder is measured. The net weight (W) of the alloy powder is measured by subtracting the tare weight of the graduated cylinder from the total weight, and the value calculated by the following equation [9] is called the tap density.
Tap density (g / ml) = W (g) / V (ml) [9]

  When the alloy powder for a phosphor raw material used in the present invention is produced by the atomizing method described above, the tap density is usually 1.9 g / ml or more, preferably 2 g / ml or more, and usually 4 g / ml. Or less, preferably 3 g / ml or less. If the tap density is too low, it may be difficult to fill the reaction vessel in the production of the phosphor, and the productivity may decrease. If the tap density is too high, the contact efficiency between the alloy particles and a firing atmosphere such as nitrogen may be reduced in the firing step.

(Oxygen and carbon content)
When the phosphor raw material alloy powder used in the present invention is produced by the above-described atomizing method or the like, the oxygen content is usually 2% by weight or less, preferably 1% by weight or less. The lower limit is usually 0.05% by weight or more, preferably 0.1% by weight or more.
When the phosphor raw material alloy powder used in the present invention is produced by the above-described atomizing method or the like, the carbon content is 0.2 wt% or less, and more preferably 0.1 wt% or less.

If the oxygen and carbon contents of the alloy powder are out of this range, the light emission characteristics of the resulting phosphor tend to deteriorate, which is not preferable.
When the alloy is pulverized using the above-described gas atomizing method or the like, impurities are less mixed as compared to the case where the alloy is mechanically pulverized using a jet mill or the like. When alloy powder with few impurities is used as a raw material, the effect that the brightness | luminance of the fluorescent substance obtained improves is acquired.

  In addition, when the above-described gas atomization method is used for pulverizing the alloy, the molten alloy hot water can be instantly formed into droplets and cooled, so that an alloy powder having a uniform microstructure can be obtained. can get. Further, since droplets are continuously formed from the same molten metal, an effect that an alloy powder having a very small composition difference between particles can be obtained. Moreover, an alloy powder having high fluidity and few impurities can be obtained.

[VI] Mixing of alloy powder and nitride or oxynitride In the primary nitriding step and / or secondary nitriding step, an alloy to be nitrided (ie, phosphor raw material alloy and / or nitrogen-containing alloy) May be heated in the presence of nitride or oxynitride, preferably after mixing with nitride or oxynitride (corresponding to 3)). The nitride or oxynitride is a nitride or oxynitride containing one or more metal elements constituting the phosphor of the present invention (hereinafter sometimes referred to as “raw material nitride”). Is used.

The composition of the raw material nitride is not particularly limited as long as it can be combined with the above-described raw material alloy and the like to obtain the target phosphor composition. Therefore, the raw material nitride, as well as the composition of the phosphor described above, more preferably containing preferably contains tetravalent metal elements M ^4, further metal elements of one or more than Si containing at least Si, More preferably, it includes an activating element M ¹ , a divalent metal element M ² , and a tetravalent metal element M ⁴ . Here, the divalent metal elements M ^2, an alkaline earth metal element is preferable. In order to obtain a uniform phosphor, it is preferable that the composition of the raw material nitride is the same constituent element as the target phosphor. For example, the raw material nitride preferably has a composition represented by the above general formula [1], and more preferably has a composition represented by the above general formula [2].

Specific examples of the raw material nitride include nitrides of elements constituting phosphors such as AlN, Si ₃ N ₄ , Ca ₃ N ₂ , Sr ₃ N ₂ , EuN, CaAlSiN ₃ , (Sr, Ca) AlSiN ₃ , Complex nitrides of elements constituting phosphors such as (Sr, Ca) ₂ Si ₅ N ₈ , SrSiN ₂ , (Sr, Ca) AlSiN ₃ : Eu, (Sr, Ca) AlSiN ₃ : Ce, (Sr, Ca ) ₂ Si ₅ N ₈ : Eu, SrSiN ₂ : Eu, composite nitride containing an activating element such as Sr _1-x Ca _x Si ₂ O ₂ N ₂ : Eu, and the like. In addition, raw material nitride may use only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio.

  The raw material nitride may contain a trace amount of oxygen. The ratio of oxygen / (oxygen + nitrogen) in the raw material nitride is arbitrary as long as the phosphor of the present invention is obtained, but is usually 0.5 or less, particularly 0.3 or less, and particularly 0.2 or less. preferable. If the proportion of oxygen in the raw material nitride is too large, the luminance may decrease.

Weight-average median diameter D ₅₀ of the raw material nitride, unless there is no problem in mixing with other materials is not particularly restricted. However, it is preferable that it is easy to mix with other raw materials, for example, it is preferable that it is comparable to an alloy powder. The specific weight median diameter D ₅₀ of the raw material nitride is arbitrary as long as a phosphor is obtained, but is preferably 200 μm or less, more preferably 100 μm or less, particularly preferably 80 μm or less, and further preferably 60 μm or less, preferably 0.1 μm or more, more preferably 0.5 μm or more.

  The mixing ratio of the raw material nitride with respect to the total amount of the phosphor raw material, that is, the mixing ratio with respect to the total of the aforementioned alloy (phosphor raw material alloy or alloy powder formed from a nitrogen-containing alloy) and the raw material nitride is usually 1 weight. % Or more, preferably 5% by weight or more, more preferably 10% by weight or more, and further preferably 15% by weight or more. When the mixing ratio of the raw material nitride is too low, the effect of improving the luminance of the obtained phosphor tends to be insufficient. On the other hand, the upper limit of the mixing ratio of the raw material nitride is not particularly limited, but if the mixing ratio of the raw material nitride is too high, the luminance of the resulting phosphor is improved, but the productivity tends to decrease. Usually, it is made into 85 weight% or less.

  In this way, when the raw material nitride is mixed with the alloy in the primary nitriding step and / or the secondary nitriding step, the heat generation rate per unit volume during nitriding can be suppressed. As a result, it is possible to suppress the phenomenon that the generated heat causes melting of the raw material, phase separation, or decomposition of the nitride, resulting in deterioration of the properties of the obtained phosphor.

  For example, when producing the phosphor of the present invention using alloy powder as a raw material, when the alloy powder is melted by heat generated during nitriding in the secondary nitriding step, the alloy particles are fused together, and nitrogen gas cannot penetrate into the interior, There is a possibility that the nitriding reaction does not proceed to the inside of the alloy particles. For this reason, the brightness | luminance of the fluorescent substance obtained tends to fall and depending on the case, it may not light-emit. However, these points are improved by mixing the raw material nitride with the alloy powder.

  Also, when the diameter of the nitriding reaction vessel is the same, if the amount of alloy powder filling is small, the heat dissipation is high, and the accumulation of heat generated during the nitriding reaction is small, so the melting and phase separation of the alloy due to the generated heat, Or a phenomenon such as decomposition of nitride or oxynitride does not occur. However, since the phosphor is synthesized at a high temperature, the energy consumption during synthesis is large, and it is preferable to increase the filling amount per time in order to reduce the cost. And if there are many alloy filling quantities of a reaction container, since heat dissipation will fall, the melt | dissolution of an alloy by the generated heat | fever, phase separation, or decomposition | disassembly of nitride or oxynitride may arise.

  On the other hand, when raw material nitride is mixed with the alloy in the primary nitriding step and / or the secondary nitriding step, the amount of heat generated is suppressed while increasing the alloy filling amount in the nitriding reaction vessel, and efficient nitriding treatment can be performed. This is probably because the melting point of nitride or oxynitride is usually higher than that of the alloy, and mixing the raw material nitride with the alloy improves the heat dissipation of the entire phosphor raw material. By preventing melting of the alloy during nitriding and allowing the nitriding reaction to proceed smoothly, a high-quality phosphor can be obtained with high productivity.

[Phosphor]
The phosphor produced by the production method of the present invention (hereinafter sometimes referred to as “the phosphor of the present invention”) will be described below. The phosphor of the present invention is preferably a phosphor based on nitride or oxynitride.
In the present specification, the matrix of the phosphor means a crystal or glass (amorphous) capable of dissolving the activating element, and the crystal or glass (amorphous) itself does not contain the activating element. Including those that emit light.

{Phosphor composition}
The composition of the phosphor of the present invention is not particularly limited as long as it is produced by the production method of the present invention, but at least a tetravalent metal element M ⁴ containing Si and 1 of a metal element other than Si. preferably comprises a type more, and more preferably further contains an activator elements M ^1. Here, as a metal element other than Si, an alkaline earth metal element is preferable.
The phosphor of the present invention preferably includes an activating element M ¹ , a divalent metal element M ² , and a tetravalent metal element M ⁴ containing at least Si, and the activating element M ¹ , divalent metal element More preferably, M ² , a trivalent metal element M ³ , and a tetravalent metal element M ⁴ including at least Si are included.

As the activator element M ¹ , various light-emitting ions that can be contained in a crystal matrix constituting a phosphor having a nitride or oxynitride as a matrix can be used, but Cr, Mn, Fe, Ce, Pr It is preferable to use one or more elements selected from the group consisting of Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb because a phosphor with high emission characteristics can be produced. The activator element M ¹ preferably contains one or more of Mn, Ce, Pr and Eu, and in particular contains phosphors that emit red or yellow light with high luminance when containing Ce and / or Eu. Is more preferable. Moreover, in order to give various functions, such as raising a brightness | luminance and providing luminous property, as activator element M1, ¹ or more types of coactivators may be contained in addition to Ce and / or Eu. good.

The elements other than the activating element M ^1, 2-valent various trivalent, can be used tetravalent metal elements. Divalent metal elements ^{M 2} is Mg, Ca, at least one element selected Sr, Ba, and from the group consisting of Zn, consisting trivalent metal elements ^{M 3} is Al, Ga, In, and from Sc It is one or more elements selected from the group, and the tetravalent metal element M ⁴ is one or more elements selected from the group consisting of Si, Ge, Sn, Ti, Zr, and Hf. It is preferable because a phosphor having a high thickness can be obtained.

Also preferred since divalent and 50 mol% or more of the metal elements M ² to adjust the composition so that the Ca and / or Sr emission characteristics of high phosphor is obtained. Among them, more preferable to divalent least 80 mole percent of the metal element ^{M 2} and Ca and / or Sr, more preferably to at least 90 mol% Ca and / or Sr, a divalent metal element M Most preferably, all of ² are Ca and / or Sr.

Further, it is preferable to adjust the composition so that 50 mol% or more of the trivalent metal element M ³ is Al since a phosphor with high emission characteristics can be obtained. Among them, it is preferable to trivalent at least 80 mole percent of the metal element M ³ and Al, be more preferably set to Al more than 90 mol%, all trivalent metal elements M ³ Al Most preferred.

In addition, it is preferable to adjust the composition so that at least 50 mol% of the tetravalent metal element M ⁴ containing Si is Si because a phosphor with high emission characteristics can be obtained. Among these, at least 80 mol% of the tetravalent metal element M ⁴ containing Si is preferably Si, more preferably 90 mol% or more is Si, and all of the tetravalent metal element M ⁴ is Si. It is preferable that

In particular, a divalent metal elements ^{M 2} of 50 mol% or more Ca and / or Sr, and 50 mol% or more trivalent metal elements ^{M 3} is Al, and tetravalent containing at least Si It is preferable that 50 mol% or more of the metal element M ⁴ is Si because a phosphor having particularly high light emission characteristics can be manufactured.

Among them, the phosphor of the present invention preferably has a chemical composition represented by the following general formula [1].
_{^{M 1 a M 2 b M 3}} c M 4 d N e O f [1]
(However, a, b, c, d, e, and f are values in the following ranges, respectively.
0.00001 ≦ a ≦ 0.15
a + b = 1
0.5 ≦ c ≦ 1.5
0.5 ≦ d ≦ 1.5
2.5 ≦ e ≦ 3.5
0 ≦ f ≦ 0.5)
In the general formula [1], M ¹ represents the activation element M ¹ , M ² represents the divalent metal element M ² , M ³ represents the trivalent metal element M ³ , M ⁴ represents the tetravalent metal element M ⁴ containing at least Si.

  In addition, the reason why the numerical range of a to f in the general formula [1] is preferable is as follows.

  When a is smaller than 0.00001, sufficient light emission intensity tends to be not obtained, and when a is larger than 0.15, concentration quenching increases and the light emission intensity tends to decrease. Accordingly, a is usually 0.00001 or more, preferably 0.0001 or more, more preferably 0.001 or more, further preferably 0.002 or more, particularly preferably 0.004 or more, and usually 0.15 or less, preferably It is preferable to mix the raw materials so as to be 0.1 or less, more preferably 0.05 or less, still more preferably 0.04 or less, and particularly preferably 0.02 or less.

the sum of a and b, since the activator elements M ¹ replaces the divalent atomic position of the metal elements M ² in the crystal matrix of the phosphor to adjust the raw material mixed composition such that the normal 1.

  When c is smaller than 0.5 or when c is larger than 1.5, a heterogeneous phase is produced during production, and the yield of the phosphor tends to be low. Accordingly, c is usually 0.5 or more, preferably 0.6 or more, more preferably 0.8 or more, and usually 1.5 or less, preferably 1.4 or less, more preferably 1.2 or less. Mixing raw materials is also preferable from the viewpoint of emission intensity.

  Whether d is smaller than 0.5 or d is larger than 1.5, a heterogeneous phase is produced during production, and the yield of the phosphor tends to be low. Therefore, d is usually 0.5 or more, preferably 0.6 or more, more preferably 0.8 or more, and usually 1.5 or less, preferably 1.4 or less, more preferably 1.2 or less. From the viewpoint of emission intensity, it is preferable to mix the raw materials.

となる。この式に０．５≦ｃ≦１．５，０．５≦ｄ≦１．５を代入すれば、ｅの範囲は
１．８４≦ｅ≦４．１７
となる。しかしながら、前記一般式［１］で表される蛍光体組成において、窒素の含有量を示すｅが２．５未満であると蛍光体の収率が低下する傾向にある。また、ｅが３．５を超えても蛍光体の収率が低下する傾向にある。従って、ｅは通常２．５≦ｅ≦３．５である。 e is a coefficient indicating the nitrogen content;

It becomes. If 0.5 ≦ c ≦ 1.5 and 0.5 ≦ d ≦ 1.5 are substituted into this equation, the range of e is 1.84 ≦ e ≦ 4.17.
It becomes. However, in the phosphor composition represented by the general formula [1], the yield of the phosphor tends to decrease when e indicating the nitrogen content is less than 2.5. Even if e exceeds 3.5, the yield of the phosphor tends to decrease. Therefore, e is usually 2.5 ≦ e ≦ 3.5.

  The oxygen in the phosphor represented by the general formula [1] may be mixed as an impurity in the raw metal, or may be introduced during a manufacturing process such as a pulverization process or a nitriding process. The oxygen content f is preferably in the range of 0 ≦ f ≦ 0.5 within a range in which a decrease in the light emission characteristics of the phosphor can be tolerated.

Among the phosphors represented by the general formula [1], the phosphor represented by the following general formula [2] can be used.
M ^{1 ′} _{a ′} Sr _{b ′} Ca _{c ′} M ^{2 ′} _{d ′} Al _{e ′} Sif _′ N _{g ′} [2]
(However, a ′, b ′, c ′, d ′, e ′, f ′, and g ′ are values in the following ranges, respectively.
0.00001 ≦ a ′ ≦ 0.15
0.1 ≦ b ′ ≦ 0.99999
0 ≦ c ′ <1
0 ≦ d ′ <1
a ′ + b ′ + c ′ + d ′ = 1
0.5 ≦ e ′ ≦ 1.5
0.5 ≦ f ′ ≦ 1.5
0.8 × (2/3 + e ′ + 4/3 × f ′) ≦ g ′ ≦ 1.2 × (2/3 + e ′ + 4/3 × f ′))

Here, M ^{1 ′} is the group consisting of Cr, Mn, Fe, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb, similarly to M ¹ in the general formula [1]. Represents an activation element selected from Among them, the activator element M ^{1 ′} preferably includes one or more of Mn, Ce, Pr, and Eu, and particularly preferably includes Eu and / or Ce.

M ^{2 ′} represents Mg and / or Ba, and is preferably Mg. Inclusion of Mg can increase the emission peak wavelength of the phosphor.

  The range of a ′ is usually 0.00001 or more, preferably 0.001 or more, more preferably 0.002 or more, and usually 0.15 or less, preferably 0.05 or less, more preferably 0.01. It is as follows.

  The range of b 'is usually 0.1 or more, preferably 0.4 or more, more preferably 0.7 or more, and usually 0.99999 or less.

  The range of c 'is usually 0 or more and usually less than 1, preferably 0.5 or less, more preferably 0.3 or less.

  The range of d 'is usually 0 or more, and usually less than 1, preferably 0.5 or less, more preferably 0.2 or less.

The relationship between a ′, b ′, c ′, d ′ is usually
a ′ + b ′ + c ′ + d ′ = 1
Satisfied.

  The range of e ′ is usually 0.5 or more, preferably 0.8 or more, more preferably 0.9 or more, and usually 1.5 or less, preferably 1.2 or less, more preferably 1.1 or less. It is.

  The range of f ′ is usually 0.5 or more, preferably 0.8 or more, more preferably 0.9 or more, and usually 1.5 or less, preferably 1.2 or less, more preferably 1.1 or less.

  The range of g ′ is usually 0.8 × (2/3 + e ′ + 4/3 × f ′) or more, preferably 0.9 × (2/3 + e ′ + 4/3 × f ′) or more, more preferably 2.5 or more, and usually 1.2 × (2/3 + e ′ + 4/3 × f ′) or less, preferably 1.1 × (2/3 + e ′ + 4/3 × f ′) or less, and more Preferably it is 3.5 or less.

  Hereinafter, a phosphor in which the value of b ′ in the general formula [2] is in the range of 0.4 ≦ b ′ ≦ 0.99999 and d ′ = 0 is referred to as “phosphor with a large amount of Sr substitution”. May be abbreviated.

Oxygen contained in the phosphor of the present invention may be mixed as an impurity in the raw metal, or mixed during a manufacturing process such as a pulverization process or a nitriding process.
The oxygen content is usually 5% by weight or less, preferably 2% by weight or less, and most preferably 1% by weight or less as long as the reduction in the light emission characteristics of the phosphor is acceptable.

Specific examples of the phosphor composition include (Sr, Ca, Mg) AlSiN ₃ : Eu, (Sr, Ca, Mg) AlSiN ₃ : Ce, (Sr, Ca, Ba) ₂ Si ₅ N ₈ : Eu, ( Sr, Ca, Ba) ₂ Si ₅ N ₈ : Ce and the like.

{Characteristics of phosphor}
The phosphor produced by the present invention may have the following characteristics, for example.

<Luminescent color>
The emission color of the phosphor of the present invention can be set to a desired emission color such as blue, blue-green, green, yellow-green, yellow, orange, and red by adjusting the chemical composition and the like.

(Emission spectrum)
For example, the phosphor of the present invention, the a Sr substitution amount is large phosphor, and, if it contains Eu as activator elements M ^1, in view of the use as an orange or red phosphor, the peak wavelength of 465nm It is preferable to have the following characteristics when the emission spectrum is measured when excited with the light.

  First, the above-mentioned phosphor preferably has a peak wavelength λp (nm) in the above-mentioned emission spectrum that is usually larger than 590 nm, particularly 600 nm or more, and usually 650 nm or less, especially 640 nm or less. If the emission peak wavelength λp is too short, it tends to be yellowish, whereas if it is too long, it tends to be dark reddish, which is not preferable because the characteristics as orange or red light may be deteriorated.

  Further, the above phosphor has a full width at half maximum (hereinafter, abbreviated as “FWHM” where appropriate) in the above-mentioned emission spectrum, which is usually larger than 50 nm, particularly 70 nm or more, and more preferably 75 nm or more. In addition, it is usually preferably less than 120 nm, more preferably 100 nm or less, and even more preferably 90 nm or less. If the full width at half maximum FWHM is too narrow, the emission intensity may decrease, and if it is too wide, the color purity may decrease.

  In order to excite the phosphor with light having a peak wavelength of 465 nm, for example, a GaN-based light emitting diode can be used. The emission spectrum of the phosphor of the present invention can be measured by, for example, a fluorescence measuring apparatus (manufactured by JASCO Corporation) equipped with a 150 W xenon lamp as an excitation light source and a multichannel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring apparatus. ) Or the like. The emission peak wavelength and the half width of the emission peak can be calculated from the obtained emission spectrum.

(Weight median diameter D ₅₀ )
The phosphor of the present invention preferably has a weight median diameter D ₅₀ in the range of usually 3 μm or more, especially 5 μm or more, and usually 30 μm or less, especially 20 μm or less. When the weight-average median diameter D ₅₀ is too small, and if the luminance is lowered, there is a case where phosphor particles tend to aggregate. On the other hand, when the weight-average median diameter D ₅₀ is too large, there is a tendency for blockage, such as uneven coating or a dispenser.
The weight-average median diameter D ₅₀ of the phosphor in the present invention, for example, can be measured using a device such as a laser diffraction / scattering particle size distribution measuring apparatus.

(Temperature characteristics)
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 150 ° C. to the emission peak intensity value in the emission spectrum diagram at 25 ° C. when light having a peak at a wavelength of 455 nm is normally 55 % Or more, preferably 60% or more, particularly preferably 70% or more.
Further, 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.

  The phosphor of the present invention is excellent in temperature characteristics not only with respect to the emission peak intensity but also in terms of luminance. Specifically, the ratio of the luminance at 150 ° C. to the luminance at 25 ° C. when irradiated with light having a peak at a wavelength of 455 nm is usually 55% or more, preferably 60% or more, particularly preferably 70%. That's it.

  When measuring the temperature characteristics, for example, an MCPD7000 multi-channel spectrum measuring device manufactured by Otsuka Electronics as an emission spectrum device, a color luminance meter BM5A as a luminance measuring device, a cooling mechanism using a Peltier element, and a heating mechanism using a heater. And it can measure as follows using the apparatus provided with a 150W xenon lamp as a light source. A cell containing a phosphor sample is placed on the stage, and the temperature is changed in the range of 20 ° C to 150 ° C. Confirm that the surface temperature of the phosphor is constant at the measurement temperature. Next, the emission spectrum is measured by exciting the phosphor with light having a peak wavelength of 455 nm extracted from the light source by spectroscopy with a diffraction grating. The emission peak intensity is obtained from the measured emission spectrum. Here, as the measured value of the surface temperature on the excitation light irradiation side of the phosphor, a value corrected using the measured temperature value by the radiation thermometer and the thermocouple is used.

(Other)
The phosphor of the present invention is more preferable as its internal quantum efficiency is higher. The value is usually 0.5 or more, preferably 0.6 or more, more preferably 0.7 or more. If the internal quantum efficiency is low, the light emission efficiency tends to decrease, which is not preferable.

  The phosphor of the present invention is preferably as its absorption efficiency is high. The value is usually 0.5 or more, preferably 0.6 or more, more preferably 0.7 or more. If the absorption efficiency is low, the light emission efficiency tends to decrease, which is not preferable.

{Use of phosphor}
The phosphor of the present invention can be suitably used for various light-emitting devices (hereinafter referred to as “light-emitting device of the present invention”) by taking advantage of its high luminance and high color rendering properties. For example, when the phosphor of the present invention is an orange or red phosphor, a white light emitting device with high color rendering can be realized by combining a green phosphor and a blue phosphor. 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. The phosphor of the present invention can be used alone. For example, an orange light emitting device can be manufactured by combining a near ultraviolet LED and the orange phosphor of the present invention.

{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 fluorescent substance containing composition of this invention, It can select arbitrarily from what was mentioned above. Moreover, the fluorescent substance of this invention contained in the fluorescent substance containing composition of this invention may be only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Furthermore, you may make the fluorescent substance containing composition of this invention contain fluorescent substances other than the fluorescent substance of this invention as needed.

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

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

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

  Among these, when using a phosphor for a high-power light-emitting device such as illumination, it is preferable to use a silicon-containing compound for the purpose of heat resistance and light resistance.

  The silicon-containing compound refers to a compound having a silicon atom in the molecule, for example, an organic material (silicone material) such as polyorganosiloxane, an inorganic material such as silicon oxide, silicon nitride, silicon oxynitride, and borosilicate. And glass materials such as phosphosilicate and alkali silicate. Among these, silicone materials are preferable from the viewpoint of ease of handling.

  The silicone material generally refers to an organic polymer having a siloxane bond as a main chain, and examples thereof include a compound represented by the following formula (i) and / or a mixture thereof.

In the above formula (i), R ¹ to R ⁶ may be the same or different and are selected from the group consisting of an organic functional group, a hydroxyl group, and a hydrogen atom.
In the above formula (i), M, D, T, and Q are numbers that are 0 or more and less than 1, respectively, and that satisfy M + D + T + Q = 1.

  When the silicone material is used for sealing a semiconductor light emitting device that can be used as a first light emitter described later, the silicone material is sealed with a liquid silicone material and then cured by heat or light. Can do.

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

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

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

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

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

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

  As such a condensation type silicone material, for example, semiconductor light emitting device members described in Japanese Patent Application Nos. 2006-47274 to 47277 and Japanese Patent Application No. 2006-176468 are suitable.

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

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

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

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

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

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

The silicon content of the silicone material suitable for the present invention is usually 20% by weight or more, preferably 25% by weight or more, and more preferably 30% by weight or more. On the other hand, the upper limit is usually 4 because the silicon content of the glass composed solely of SiO ₂ is 47% by weight.
The range is 7% by weight or less.

  The silicon content of the silicone material is calculated based on the result of inductively coupled plasma spectrometry (hereinafter abbreviated as “ICP” where appropriate) using, for example, the following method. be able to.

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

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

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

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

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

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

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

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

(Equipment conditions)
Apparatus: Chemagnetics InfinityCMX-400 nuclear magnetic resonance spectrometer 29Si resonance frequency: 79.436 MHz
Probe: 7.5 mmφ CP / MAS probe Measurement temperature: room temperature Sample rotation speed: 4 kHz
Measurement method: Single pulse method 1H decoupling frequency: 50 kHz
29Si flip angle: 90 ° 29Si90 ° pulse width: 5.0μs
Repeat time: 600s
Integration count: 128 Observation width: 30 kHz
Broadening factor: 20Hz
Reference sample: Tetramethoxysilane

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

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

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

  In addition, the silanol content rate of a silicone type material uses the method demonstrated in the section of (the solid Si-NMR spectrum measurement and calculation of silanol content rate) of <feature [2] (solid Si-NMR spectrum)>, for example. The solid Si-NMR spectrum measurement is performed, and the ratio (%) of silicon atoms that are silanols in all silicon atoms is obtained from the ratio of the peak area derived from silanol to the total peak area, and compared with the silicon content analyzed separately. This can be calculated.

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

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

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

<Content of liquid medium>
The content of the liquid medium of the phosphor-containing composition of the present invention is arbitrary as long as the effects of the present invention are not significantly impaired, but usually 50% by weight or more, preferably with respect to the entire phosphor-containing composition of the present invention. Is 75% by weight or more, usually 99% by weight or less, preferably 95% by weight or less. When the amount of the liquid medium is large, no particular problem occurs. However, in order to obtain the desired chromaticity coordinates, color rendering index, luminous efficiency, etc. in the case of a light emitting device, the liquid is usually mixed at the above blending ratio. It is desirable to use a medium. On the other hand, if there is too little liquid medium, there is a possibility that it will be difficult to handle due to lack of fluidity.

  The liquid medium mainly 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 a silicon-containing compound is used for the purpose of heat resistance, light resistance, etc., other thermosetting resins such as an epoxy resin may be contained to the extent that the durability of the silicon-containing compound is not impaired. In this case, the content of the other thermosetting resin is usually 25% by weight or less, preferably 10% by weight or less based on the total amount of the liquid medium as the binder.

<Other ingredients>
In addition, you may make the fluorescent substance containing composition of this invention contain other components other than a fluorescent substance and a liquid medium, unless the effect of this invention is impaired remarkably. Moreover, only 1 type may be used for another component and it may use 2 or more types together by arbitrary combinations and a ratio.

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

{Light emitting device}
Next, the light emitting device of the present invention will be described.
The light-emitting device of the present invention (hereinafter referred to as “light-emitting device” as appropriate) includes a first light-emitting body (excitation light source), and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body. The second light emitter contains one or more of the phosphors of the present invention described above as the first phosphor.

The phosphor of the present invention used in the light emitting device of the present invention is not particularly limited in its composition and emission color as long as it is the phosphor of the present invention described above. For example, the phosphor of the present invention is represented by the general formula [2], and, if it contains Eu as activator elements M ^1, the phosphor of the present invention is usually irradiated with light from the excitation light source Below, the phosphor emits fluorescence in the orange or red region (hereinafter sometimes referred to as “the orange or red phosphor of the present invention”). Specifically, when the phosphor of the present invention is an orange or red phosphor, those having an emission peak in a wavelength range of 590 nm to 640 nm are preferable. Any one of the phosphors of the present invention may be used alone, or two or more thereof may be used in any combination and ratio.

Further, the weight median diameter D ₅₀ of the phosphor of the present invention used in the light emitting device of the present invention is preferably in the range of usually 10 μm or more, particularly 15 μm or more, and usually 30 μm or less, especially 20 μm or less. When the weight-average median diameter D ₅₀ is too small, and the luminance decreases tends to phosphor particles tend to aggregate. On the other hand, if too large weight-average median diameter D _50, tends to blockage such as uneven coating or a dispenser.

  Further, preferred specific examples of the phosphor of the present invention used in the light emitting device of the present invention include the phosphor of the present invention described in the above-mentioned {Phosphor composition} column and the below-mentioned [Example] column. The phosphor used in each of the examples.

  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.

  As the light emission peak in the orange to red region in the light emission spectrum of the light emitting device of the present invention, one having a light emission peak in the wavelength range of 590 nm to 670 nm is preferable.

  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 orange or red phosphor as described above, as described later. A phosphor that emits green fluorescence (hereinafter referred to as “green phosphor” as appropriate), a phosphor that emits blue fluorescence (hereinafter referred to as “blue phosphor” as appropriate), and a phosphor that emits yellow fluorescence (hereinafter referred to as “ It can be obtained by using known phosphors such as “yellow phosphor” in any combination and using a known apparatus configuration.

  Here, the white color of the white light emitting device includes all of (yellowish) white, (greenish) white, (blueish) white, (purple) white, and white defined by JISZ8701. Of these, white is preferred.

<Configuration of light-emitting device (light-emitting body)>
(First luminous body)
The 1st light-emitting body in the light-emitting device of this invention light-emits the light which excites the 2nd light-emitting body mentioned later.

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

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

  As the first light emitter, a semiconductor light emitting element is generally used, and specifically, a light emitting LED, a semiconductor laser diode (hereinafter abbreviated as “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 light output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely low power and extremely low power when combined with the phosphor of the present invention. This is because bright light emission can be obtained. For example, for a current load of 20 mA, GaN-based LEDs and LDs usually have a light emission intensity 100 times or more that of SiC-based. GaN-based LEDs and LDs preferably have an Al _X Ga _Y N light emitting layer, a GaN light emitting layer, or an In _X Ga _Y N light emitting layer. In the GaN-based LED, the one having _{an In} X Ga _Y N emission layer Among these particularly preferred because the emission intensity is very strong, the GaN-based LED is _In X Ga _Y N layer and the multiple quantum well structure of GaN layer Is particularly preferable because the emission intensity is very strong.

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

A GaN-based LED has these light-emitting layer, p-layer, n-layer, electrode, and substrate as basic components, and the light-emitting layer is 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 the phosphor of the present invention described above (for example, the first phosphor) (for example, , An orange or red phosphor), and a second phosphor (for example, a green phosphor, a blue phosphor, a yellow phosphor, etc.), which will be described later, as appropriate depending on the application. Further, for example, the second light emitter is configured by dispersing the first and second phosphors in a sealing material.

Used for the in the second luminescent material is not particularly limited to the phosphor composition other than the phosphor of the present invention, the crystal _{matrix, Y 2 O 3, YVO 4} , Zn 2 SiO 4, Y 3 Metal oxides typified by Al ₅ O ₁₂ , Sr ₂ SiO ₄ , metal nitrides typified by Sr ₂ Si ₅ N ₈ , phosphates typified by Ca ₅ (PO ₄ ) ₃ Cl, etc. Ce, Pr, Nd, Pm, Sm, Eu, Tb, Dy, sulfide represented by ZnS, SrS, CaS, etc., oxysulfide represented by Y ₂ O ₂ S, La ₂ O ₂ S, etc. A combination of rare earth metal ions such as Ho, Er, Tm, and Yb, and metal ions such as Ag, Cu, Au, Al, Mn, and Sb as activators or coactivators.

Preferred examples of the crystal matrix include sulfides such as (Zn, Cd) S, SrGa ₂ S ₄ , SrS, and ZnS; oxysulfides such as Y ₂ O ₂ S; (Y, Gd) ₃ Al ₅ O ₁₂ , YAlO ₃ , BaMgAl ₁₀ O ₁₇ , (Ba, Sr) (Mg, Mn) Al ₁₀ O ₁₇ , (Ba, Sr, Ca) (Mg, Zn, Mn) Al ₁₀ O ₁₇ , BaAl ₁₂ O ₁₉ , CeMgAl Aluminate such as ₁₁ O ₁₉ , (Ba, Sr, Mg) O.Al ₂ O ₃ , BaAl ₂ Si ₂ O ₈ , SrAl ₂ O ₄ , Sr ₄ Al ₁₄ O ₂₅ , Y ₃ Al ₅ O ₁₂ ; Y Silicates such as ₂ SiO ₅ and Zn ₂ SiO ₄ ; Oxides such as SnO ₂ and Y ₂ O ₃ ; Borates such as GdMgB ₅ O ₁₀ and (Y, Gd) BO ₃ ; Ca ₁₀ (PO ₄ ) ₆ ( _{F, Cl) 2, (Sr} , Ca, Ba, g) ₁₀ (PO ₄₎ such as ₆ Cl _{2 halophosphate;} Sr ₂ P _{2 O 7,} can be cited (La, Ce) phosphate PO _4, etc. and the like.

  However, the crystal matrix 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 second light emitter in the light emitting device of the present invention contains at least the above-described phosphor of the present invention as the first phosphor. Any one of the phosphors of the present invention may be used alone, or two or more thereof may be used in any combination and ratio. In addition to the phosphor of the present invention, a phosphor that emits fluorescence of the same color as the phosphor of the present invention (same color combined phosphor) may be used as the first phosphor. For example, the phosphor of the present invention, the represented by the general formula [2], and, in the case of containing Eu as activator elements M ^1, usually, since the phosphor of the present invention is a orange or red phosphor As the first phosphor, another type of orange or red phosphor can be used in combination with the phosphor of the present invention.

Any orange or red phosphor may 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, which is the same color combination phosphor, is usually 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. It is preferable to be in the following wavelength range.

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

  Furthermore, an oxynitride and / or an acid containing at least one element selected from the group consisting of Ti, Zr, Hf, Nb, Ta, W, and Mo described in JP-A No. 2004-300247 A phosphor containing a sulfide and containing an oxynitride having an alpha sialon structure in which a part or all of the Al element is substituted with a Ga element can also be used in the present invention. These are phosphors containing oxynitride and / or oxysulfide.

In addition, examples of red phosphors include Eu-activated oxysulfide phosphors such as (La, Y) ₂ O ₂ S: Eu, Y (V, P) O ₄ : Eu, and Y ₂ O ₃ : Eu. Eu-activated oxide phosphor, (Ba, Mg) ₂ SiO ₄ : Eu, Mn, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, Mn-activated silicate phosphor such as Eu, Mn, Eu-activated tungstate phosphors such as LiW ₂ O ₈ : Eu, LiW ₂ O ₈ : Eu, Sm, Eu ₂ W ₂ O ₉ , Eu ₂ W ₂ O ₉ : Nb, Eu ₂ W ₂ O ₉ : Sm (Ca, Sr) S: Eu-activated sulfide phosphors such as Eu, YAlO ₃ : Eu-activated aluminate phosphors such as Eu, Ca ₂ Y ₈ (SiO ₄ ) ₆ O ₂ : Eu, LiY _{9 (SiO 4) 6 O 2:} Eu, (Sr, Ba, Ca) 3 SiO 5: Eu, Sr BaSiO _5: Eu-activated silicate phosphors such as _{Eu, (Y, Gd) 3} Al 5 O 12: Ce, (Tb, Gd) 3 Al 5 O 12: Ce -activated aluminate phosphor such as Ce, (Mg, Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Mg, Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Mg, Ca, Sr, Ba) AlSi (N, O) ₃ : Eu activated oxide such as Eu, nitride or oxynitride phosphor, (Mg, Ca, Sr, Ba) AlSi (N, O) ₃ : Ce activated oxide such as Ce , Nitride or oxynitride phosphor, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, Mn activated halophosphate phosphor such as Eu, Mn, Ba ₃ MgSi ₂ O ₈ : Eu, Mn, (Ba, Sr, Ca, Mg) ₃ (Zn, Mg) Si ₂ O ₈ : Eu Eu, Mn activated silicate phosphor such as Mn, Mn, etc., 3.5MgO · 0.5MgF ₂ · GeO ₂ : Mn activated germanate phosphor such as Mn, Eu activated oxynitride such as Eu activated α sialon Phosphor, (Gd, Y, Lu, La) ₂ O ₃ : Eu, Bi activated oxide phosphor such as Eu, Bi, (Gd, Y, Lu, La) ₂ O ₂ S: Eu, Bi, etc. Eu, Bi-activated oxysulfide phosphors, (Gd, Y, Lu, La) VO ₄ : Eu, Bi-activated vanadate phosphors, SrY ₂ S ₄ : Eu, Ce, etc. Eu, Ce activated sulfide phosphor, Ce activated sulfide phosphor such as CaLa ₂ S ₄ : Ce, (Ba, Sr, Ca) MgP ₂ O ₇ : Eu, Mn, (Sr, Ca, Ba, Mg) _{, Zn) 2 P 2 O 7} : Eu, Eu such as Mn, Mn-activated phosphate phosphor, (Y, _{Lu) 2} O _6: Eu, Eu such as Mo, Mo-activated tungstate _{phosphor, (Ba, Sr, Ca)} x Si y N z: Eu, Ce ( provided that, x, y, z are an integer of 1 or more Represent. Eu, Ce-activated nitride phosphors such as (Ca, Sr, Ba, Mg) ₁₀ (PO ₄ ) ₆ (F, Cl, Br, OH): Eu, Mn-activated halophosphoric acid such as Eu, Mn Salt phosphors, ((Y, Lu, Gd, Tb) _1-xy Sc _x Ce _y ) ₂ (Ca, Mg) _1-r (Mg, Zn) _{2 + r} Si _z-q Ge _q O _{12 + δ and} other Ce It is also possible to use an activated silicate phosphor or the like.

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

Among these, as red phosphors, (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si (N, O) ₂ : Eu, (Ca, Sr , Ba) AlSi (N, O) ₃ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Ce, (Sr, Ba) ₃ SiO ₅ : Eu, (Ca, Sr) S: Eu, It is preferable to contain (La, Y) ₂ O ₂ S: Eu or Eu complex, more preferably (Ca, Sr, Ba) ₂ Si ₅ (N, O) ₈ : Eu, (Ca, Sr, Ba) Si. (N, O) ₂ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Eu, (Ca, Sr, Ba) AlSi (N, O) ₃ : Ce, (Sr, Ba) ₃ SiO _{5: Eu, (Ca, Sr} ) S: Eu or _{(La, Y) 2 O 2} S: Eu, or Eu ( Preferably comprises a _{dibenzoylmethane)} 3 · 1,10-beta-diketone Eu complex or carboxylic acid Eu complex phenanthroline complex, _{etc., (Ca, Sr, Ba)} 2 Si 5 (N, O) 8: Eu (Sr, Ca) AlSiN ₃ : Eu or (La, Y) ₂ O ₂ S: Eu is particularly preferred.

Moreover, among the above examples, (Sr, Ba) ₃ SiO ₅ : Eu is preferable as the orange phosphor.
Any one of the orange to red phosphors exemplified above may be used alone, or two or more may be used in any combination and ratio.

(Second phosphor)
The second light emitter in the light emitting device of the present invention may contain a phosphor (that is, a second phosphor) in addition to the first phosphor described above, depending on the application. This second phosphor is a phosphor having an emission peak wavelength different from that of the first phosphor. Usually, since these second phosphors are used to adjust the color tone of light emitted from the second light emitter, the second phosphor emits fluorescence having a color different from that of the first phosphor. Often phosphors are used. As described above, when an orange or red phosphor is used as the first phosphor, examples of the second phosphor include a first phosphor such as a green phosphor, a blue phosphor, and a yellow phosphor. Use phosphors that emit different colors.

The weight median diameter of the second phosphor used in the light emitting device of the present invention is usually in the range of 10 μm or more, especially 12 μm or more, and usually 30 μm or less, especially 25 μm or less. When the weight-average median diameter D ₅₀ is too small, and the luminance decreases tends to phosphor particles tend to aggregate. On the other hand, if too large weight-average median diameter D _50, tends to blockage such as uneven coating or a dispenser.

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

Such a blue phosphor is composed of grown particles having a substantially hexagonal shape as a regular crystal growth shape, and is represented by (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu that emits light in a blue region. Europium activated barium magnesium aluminate-based phosphor, composed of growing particles having a substantially spherical shape as a regular crystal growth shape, emits light in the blue region (Mg, Ca, Sr, Ba) ₅ (PO ₄ ) ₃ ( Cl, F): a europium-activated calcium halophosphate phosphor represented by Eu, and composed of grown particles having a substantially cubic shape as a regular crystal growth shape, and emits light in a blue region (Ca, Sr, Ba) ₂ A europium-activated alkaline earth chloroborate-based phosphor represented by B ₅ O ₉ Cl: Eu, comprising fractured particles having a fracture surface Europium-activated alkaline earth aluminate system represented by (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu Examples thereof include phosphors.

In addition, as the blue phosphor, Sn-activated phosphate phosphor such as Sr ₂ P ₂ O ₇ : Sn, (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, BaMgAl ₁₀ O ₁₇ : Eu, Tb, Sm, BaAl ₈ O ₁₃ : with Eu, etc. Active aluminate phosphor, Ce-activated thiogallate phosphor such as SrGa ₂ S ₄ : Ce, CaGa ₂ S ₄ : Ce, Eu, Mn such as (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, Mn Active aluminate phosphor, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu, (Ba, Sr, Ca) ₅ (PO ₄ ) ₃ (Cl, F, Br, OH): Eu, Mn Eu-activated halophosphate phosphor such as Sb, Sb, BaAl ₂ Si ₂ O ₈ : Eu, (Sr, Ba) ₃ MgSi ₂ O ₈ : Eu-activated silicate phosphor such as Eu, Sr ₂ P ₂ O ₇ : Eu-activated phosphate phosphors such as Eu, sulfide phosphors such as ZnS: Ag, ZnS: Ag, Al, Ce-activated silicate phosphors such as Y ₂ SiO ₅ : Ce, tungsten such as CaWO _{4 phosphors, (Ba, Sr, Ca)} BPO 5: Eu, Mn, (Sr, Ca) 10 (PO 4) 6 · nB 2 O 3: Eu, 2SrO · 0.84P 2 O 5 · 0.16B ₂ O ₃ : Eu, Mn activated borate phosphate phosphor such as Eu, Sr ₂ Si ₃ O ₈ · 2SrCl ₂ : Eu activated halosilicate phosphor such as Eu, SrSi ₉ Al ₁₉ ON ₃₁ : Eu, EuSi ₉ Al ₁₉ Eu-activated of ON _31, etc. Nitride _{phosphor, La 1-x Ce x Al} (Si 6-z Al z) (N 10-z O z) ( here, x, and y are each 0 ≦ x ≦ 1,0 ≦ z ≦ 6 is a number _{satisfying.), La 1-x-} y Ce x Ca y Al (Si 6-z Al z) (N 10-z O z) ( here, x, y, and z are each 0 It is also possible to use Ce-activated oxynitride phosphors such as ≦ x ≦ 1, 0 ≦ y ≦ 1, and 0 ≦ z ≦ 6.

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

Among the above examples, as the blue phosphor, (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Eu or It is preferable to contain (Ba, Ca, Mg, Sr) ₂ SiO ₄ : Eu, and (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ (PO Cl, F) ₂ : Eu or (Ba, Ca, Sr) ₃ MgSi ₂ O ₈ : Eu is more preferable, and BaMgAl ₁₀ O ₁₇ : Eu, Sr ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : More preferably, Eu or Ba ₃ MgSi ₂ O ₈ : Eu is included. Of these, (Sr, Ca, Ba, Mg) ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu or (Ca, Sr, Ba) MgAl ₁₀ O ₁₇ : Eu is particularly preferable for illumination and display applications.

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

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

Such yellow phosphors include various oxides, nitrides, oxynitrides, sulfides,
Examples thereof include phosphors such as oxysulfides.
In particular, RE ₃ M ₅ O ₁₂ : Ce (where RE represents at least one element selected from the group consisting of Y, Tb, Gd, Lu, and Sm, and M represents Al, Ga, and Sc. And M ^a ₃ M ^b ₂ M ^c ₃ O ₁₂ : Ce (where M ^a is a divalent metal element and M ^b is a trivalent metal element) , ^{M c} is garnet phosphor having a garnet structure represented by the representative) like a tetravalent metallic ^{_{element, AE 2 M d O 4:}} . Eu ( where, AE is, Ba, Sr, Ca, Mg , And at least one element selected from the group consisting of Zn, and M ^d represents Si and / or Ge)), etc., and constituent elements of the phosphors of these systems Oxynitride Phosphors in which a Part of Oxygen is Replaced with Nitrogen AEAlSiN _3: Ce (., Where, AE is, Ba, Sr, Ca, Mg and represents at least one element selected from the group consisting of Zn) of the nitride-based fluorescent material or the like having a CaAlSiN ₃ structure, such as Ce And the phosphor activated by the above.

In addition, as yellow phosphors, sulfide-based fluorescence such as CaGa ₂ S ₄ : Eu, (Ca, Sr) Ga ₂ S ₄ : Eu, (Ca, Sr) (Ga, Al) ₂ S ₄ : Eu, etc. Body, Cax (Si, Al) ₁₂ (O, N) ₁₆ : phosphor activated by Eu such as an oxynitride phosphor having a SiAlON structure such as Eu, (M _1-A-A Eu _A Mn _A ) ₂ (BO ₃ ) _1-P (PO ₄ ) _P X (where M represents one or more elements selected from the group consisting of Ca, Sr, and Ba, and X represents F, Cl, and Br) Represents one or more elements selected from the group consisting of: A, B, and P are 0.001 ≦ A ≦ 0.3, 0 ≦ B ≦ 0.3, and 0 ≦ P ≦ 0.2, respectively. It is also possible to use Eu-activated or Eu / Mn co-activated halogenated borate phosphors, etc. That.

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

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

<Green phosphor>
When a green phosphor is used as the second phosphor, 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 preferably in the range of usually 500 nm or more, particularly 510 nm or more, more preferably 515 nm or more, and usually 550 nm or less, especially 542 nm or less, more 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.

Specifically, the green phosphor is composed of, for example, fractured particles having a fractured surface, and emits a green region with (Mg, Ca, Sr, Ba) Si ₂ O ₂ N ₂ : with europium represented by Eu. Examples include active alkaline earth silicon oxynitride phosphors.

Other green phosphors include Eu-activated aluminate phosphors such as Sr ₄ Al ₁₄ O ₂₅ : Eu, (Ba, Sr, Ca) Al ₂ O ₄ : Eu, and (Sr, Ba) Al _2. Si ₂ O ₈ : Eu, (Ba, Mg) ₂ SiO ₄ : Eu, (Ba, Sr, Ca, Mg) ₂ SiO ₄ : Eu, (Ba, Sr, Ca) ₂ (Mg, Zn) Si ₂ O ₇ : Eu, (Ba, Ca, Sr, Mg) ₉ (Sc, Y, Lu, Gd) ₂ (Si, Ge) ₆ O ₂₄ : Eu-activated silicate phosphor such as Eu, Y ₂ SiO ₅ : Ce, Ce, Tb-activated silicate phosphors such as Tb, Sr ₂ P ₂ O ₇ —Sr ₂ B ₂ O ₅ : Eu-activated borate phosphate phosphors such as Eu, Sr ₂ Si ₃ O ₈ -2SrCl ₂ : Eu-activated halo silicate phosphor such as _Eu, Zn 2 _SiO 4: M such as Mn Activated silicate _{phosphors, CeMgAl 11 O 19: Tb,} Y 3 Al 5 O 12: Tb -activated aluminate phosphors such as _{Tb, Ca 2 Y 8 (SiO} 4) 6 O 2: Tb, La 3 Ga ₅ SiO ₁₄ : Tb-activated silicate phosphor such as Tb, (Sr, Ba, Ca) Ga ₂ S ₄ : Eu, Tb, Sm-activated thiogallate phosphor such as Eu, Tb, Sm, Y ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Y, Ga, Tb, La, Sm, Pr, Lu) ₃ (Al, Ga) ₅ O ₁₂ : Ce-activated aluminate phosphor such as Ce, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, Ca ₃ (Sc, Mg, Na, Li) ₂ Si ₃ O ₁₂ : Ce activated silicate phosphor such as Ce, Ce activated oxide phosphor such as CaSc ₂ O ₄ : Ce, Eu-activated oxynitride phosphors such as Eu-activated β sialon BaMgAl ₁₀ O _17: Eu, Eu such as Mn, Mn-activated aluminate phosphor, SrAl ₂ O _4: Eu-activated aluminate phosphor such as _{Eu, (La, Gd, Y} ) 2 O 2 S: Tb-activated oxysulfide phosphors such as Tb, LaPO ₄ : Ce, Tb-activated phosphate phosphors such as Ce, Tb, and sulfide phosphors such as ZnS: Cu, Al, ZnS: Cu, Au, Al _{, (Y, Ga, Lu,} Sc, La) BO 3: Ce, Tb, Na 2 Gd 2 B 2 O 7: Ce, Tb, (Ba, Sr) 2 (Ca, Mg, Zn) B 2 O 6: Ce, Tb activated borate phosphors such as K, Ce, Tb, Eu, Mn activated halosilicate phosphors such as Ca ₈ Mg (SiO ₄ ) ₄ Cl ₂ : Eu, Mn, (Sr, Ca, Ba _{) (Al, Ga, in)} 2 S 4: Eu activated thioaluminate such as Eu Light body and thiogallate _{phosphor, (Ca, Sr) 8 (} Mg, Zn) (SiO 4) 4 Cl 2: Eu, Eu such as Mn, Mn-activated halo silicate _{phosphor, M 3 Si 6 O 9 N} 4 : Eu, M ₃ Si ₆ O ₁₂ N ₂ : Eu (where M represents an alkaline earth metal element). It is also possible to use Eu-activated oxynitride phosphors such as

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

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

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

  In the light emitting device of the present invention, the presence / absence and type of the second phosphor (yellow phosphor, blue phosphor, green phosphor, etc.) described above may be appropriately selected according to the use of the light emitting device. . For example, when the light emitting device of the present invention is configured as an orange or red light emitting device, only the first phosphor (orange or red phosphor) may be used, and the second phosphor is usually used. Is unnecessary.

  On the other hand, when the light-emitting device of the present invention is configured as a light-emitting device that emits white light, the first light-emitting body, the first phosphor (orange or red phosphor), and a desired white light are obtained. What is necessary is just to combine a 2nd fluorescent substance appropriately. Specifically, examples of preferable combinations of the first light emitter, the first phosphor, and the second phosphor in the case where the light emitting device of the present invention is configured as a white light emitting device include the following: (I) to (iii) are included.

(I) A blue phosphor (such as a blue LED) is used as the first phosphor, a red phosphor (such as the phosphor of the present invention) is used as the first phosphor, and green fluorescence is used as the second phosphor. Use the body.

(Ii) A near ultraviolet light emitter (near ultraviolet LED or the like) is used as the first light emitter, a red phosphor (such as the phosphor of the present invention) is used as the first phosphor, and the second phosphor is used as the second phosphor. A blue phosphor and a green phosphor are used in combination.

(Iii) A blue phosphor (such as a blue LED) is used as the first phosphor, an orange phosphor (such as the phosphor of the present invention) is used as the first phosphor, and green fluorescence is used as the second phosphor. Use the body.

Specific examples of the above phosphor combinations are listed in the following Tables a) to h).
However, (Ca, Sr) AlSiNi ₃ : Eu exemplified as the deep red phosphor in the following Tables d), h) and Table 5) below refers to the amount of Ca relative to the total amount of Ca and Sr. It is a phosphor having an emission peak wavelength in the range of 40 mol% or more and a wavelength of 630 nm to 700 nm, and may be the phosphor of the present invention.

  Among these combinations, a light emitting device using a semiconductor light emitting element and a phosphor in combinations shown in the following Tables 1) to 7) is particularly preferable.

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

<Sealing material>
In the light emitting device of the present invention, the first and / or second phosphors are usually used by being dispersed in a liquid medium that is a sealing material.
Examples of the liquid medium include the same ones described in the above-mentioned section {Phosphor-containing composition}.

  The liquid medium can contain a metal element that can be a metal oxide having a high refractive index in order to adjust the refractive index of the sealing member. Examples of metal elements that give a metal oxide having a high refractive index include Si, Al, Zr, Ti, Y, Nb, and B. These metal elements may be used alone or in combination of two or more in any combination and ratio.

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

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

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

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

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

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

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

  FIG. 2B is a 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 resin portion as a phosphor-containing portion (second light emitter), reference numeral 24 is a frame, reference numeral 25 is a conductive wire, Reference numerals 26 and 27 indicate electrodes.

<Applications of light emitting device>
The application of the light-emitting device of the present invention is not particularly limited and can be used in various fields where ordinary light-emitting devices are used. However, since the color reproduction range is wide and the color rendering property is high, illumination is particularly important. It is particularly preferably used as a light source for a device or an image display device.

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

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

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

{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 each Example and each Comparative Example described later, various evaluations were performed by the following methods.

(Measurement of weight change and melting point)
Thermogravimetry-differential thermal analysis (TG-DTA) measuring device (TG-DTA2000, manufactured by Bruker AXS, Inc.) using 10 mg of the alloy powder or the nitrogen-containing alloy of each example and each comparative example. ) Was heated from room temperature to 1500 ° C. at a heating rate of 10 ° C./min under an atmosphere gas (nitrogen, argon, or mixed gas of nitrogen and argon) 100 ml / min, and the change in weight was measured.
In the graphs showing the measurement results (FIGS. 5 and 10), the left vertical axis represents the sample temperature (° C.), and the right vertical axis represents the weight change rate (% / hour).
Further, in the TG-DTA measurement in an argon stream, the endotherm accompanying melting was detected, and the temperature at which the endothermic peak appeared was defined as the melting point. In the measurement of the melting point, temperature calibration was performed using Au (melting point: 1063 ° C.) and Si (melting point: 1410 ° C.).

(Measurement of weight increase rate)
The weight increase rate was determined by measuring the weights of the alloy powder before the primary nitriding step and the nitrogen-containing alloy after the primary nitriding step, and the following formula [4].
(Weight of nitrogen-containing alloy after primary nitriding step-weight of alloy powder before primary nitriding step)
/ Weight of alloy powder before primary nitriding step × 100 ... [4]

(Measurement of total metal element content)
The total metal element content was determined by measuring the weights of the alloy powder before the primary nitriding step and the nitrogen-containing alloy after the primary nitriding step, using the following equation [5].
Total metal element content (wt%)
= 100-{(weight of nitrogen-containing alloy after primary nitriding step-weight of alloy before primary nitriding step)
/ Weight of nitrogen-containing alloy after primary nitriding step} × 100 (5)

(Measurement of nitrogen content)
The nitrogen content is determined by measuring the nitrogen content of the nitrogen-containing alloy or phosphor with an oxygen-nitrogen simultaneous analyzer (manufactured by Leco). The nitrogen content of the nitrogen-containing alloy is determined by the following formula [6], The nitrogen content of can be obtained by the following formula [6A].
Nitrogen content of nitrogen-containing alloy (wt%)
= (Nitrogen content / weight of nitrogen-containing alloy after primary nitriding step) x 100 ... [6]
Nitrogen content of phosphor (wt%)
= (Nitrogen content / phosphor weight) x 100 ... [6A]

(Measurement of oxygen content)
The oxygen content is determined by measuring the oxygen content of the nitrogen-containing alloy or phosphor with an oxygen-nitrogen simultaneous analyzer (manufactured by Leco Co.). The oxygen content of can be obtained by the following formula [8A].
Oxygen content of nitrogen-containing alloy (wt%)
= (Oxygen content / weight of the nitrogen-containing alloy after the primary nitriding step) x 100 ... [8]
Oxygen content of phosphor (wt%)
= (Oxygen content / phosphor weight) x 100 ... [8A]

(NI / NP calculation method)
NI / NP was calculated | required by following formula [7] from the measurement result of nitrogen content rate.
0.03 ≦ NI / NP ≦ 0.9 [7]
(In Formula [7],
NI represents the nitrogen content (% by weight) contained in the nitrogen-containing alloy,
NP represents the nitrogen content (% by weight) contained in the produced phosphor. )

(Measurement of weight median diameter D ₅₀ of alloy powder)
In an environment where the temperature is 25 ° C. and the humidity is 70%, an alloy powder sample is dispersed in ethylene glycol, and measured with a laser diffraction particle size distribution measuring device (Horiba LA-300) in a particle size range of 0.1 μm to 600 μm. determined from the obtained weight particle size distribution curve, the accumulated value is the particle size value when the 50% and weight-average median diameter D _50. Further, the particle diameter values when the integrated value is 25% and 75% are D ₂₅ and D ₇₅ , respectively, and QD is calculated by QD = (D ₇₅ −D ₂₅ ) / (D ₇₅ + D ₂₅ ).

(Measurement of weight median diameter D ₅₀ of phosphor)
Before the measurement, an ultrasonic disperser (manufactured by Kaijo Corporation) was used, the frequency was 19 KHz, the intensity of the ultrasonic wave was 5 W, and the sample was dispersed with ultrasonic waves for 25 seconds. In addition, in order to prevent re-aggregation, water to which a small amount of a surfactant was added was used for the dispersion.
In the measurement of the weight median diameter, a laser diffraction / scattering particle size distribution measuring device (manufactured by Horiba, Ltd.) was used.

(X-ray powder diffraction measurement)
Measurement was performed in the air under the following conditions using an XPert MPD manufactured by Philips.
Step size [° 2 Th. ] 0.0500
Start position [° 2 Th. ] 10.0350
End pos. [° 2 Th. ] 89.9350
X-ray output setting 45kV, 40mA
Divergent slit (DS) size [°] 1.0000
Receiving slit (RS) size [mm] 1.0000
Scan type CONTINUOUS
Scan step time [s] 33.0000
Measurement temperature [° C] 0.00
Goniometer radius [mm] 200.00
Distance between focus and DS [mm] 91.00
Irradiation width [mm] 10.00
Sample width [mm] 10.00
Scan axis Goniometer Incident side monochromator None Target Cu
CuKα (1.541mm)

(Analysis of chemical composition)
The analysis was performed by ICP emission spectrometry (Inductively Coupled Plasma-Atomic Emission Spectrometry; hereinafter referred to as “ICP method”) using an ICP chemical analyzer “JY 38S” manufactured by Jobibon.

(Measurement of electrical conductivity of supernatant liquid in water dispersion test)
After classification with a sieve and sizing to a median diameter of 9 μm (however, when the weight median diameter of the washed phosphor particles is 9 μm, this operation is not performed), the phosphor particles are adjusted to the weight of the phosphor. The mixture was placed in 10 times the amount of water and dispersed by stirring for 10 minutes using a stirrer. After standing for 1 hour, it was confirmed that the phosphor had settled, and the electrical conductivity of the supernatant was measured.
The electric conductivity was measured using an electric conductivity meter “EC METER CM-30G” manufactured by Toa Decay. Washing and measurement were performed at room temperature.
In addition, the electrical conductivity of the water used for the washing | cleaning and the water dispersion test of fluorescent substance in each Example and each comparative example is 0.03 mS / m.

(Measurement of emission spectrum)
The emission spectrum of the phosphor was measured using a 150 W xenon lamp as an excitation light source and a fluorescence measuring apparatus (manufactured by JASCO Corporation) equipped with a multi-channel CCD detector C7041 (manufactured by Hamamatsu Photonics) as a spectrum measuring apparatus. The light from the excitation light source was passed through a diffraction grating spectrometer having a focal length of 10 cm, and only the excitation light having a wavelength of 465 nm was irradiated to the phosphor through the optical fiber. The light generated from the phosphor by the irradiation of the excitation light is dispersed by a diffraction grating spectrometer having a focal length of 25 cm, and the emission intensity of each wavelength is measured by a spectrum measuring device in a wavelength range of 300 nm or more and 800 nm or less. An emission spectrum was obtained through signal processing such as sensitivity correction.

(Measurement of emission peak wavelength, relative emission peak intensity and relative luminance)
The emission peak wavelength was read from the obtained emission spectrum.
The relative emission peak intensity was expressed as a relative value based on the emission peak intensity of the phosphor of Reference Example 1 below.
Moreover, the relative brightness | luminance which made the value of the stimulus value Y of the fluorescent substance in the following reference example 1 100% from the stimulus value Y in the XYZ color system calculated based on JISZ8724 was calculated. The luminance was measured by cutting excitation blue light.
Reference example 1
Ca ₃ N ₂ (200 mesh pass manufactured by CERAC), AlN (manufactured by Tokuyama Co., Ltd.) so that the metal element composition ratio is Eu: Ca: Al: Si = 0.008: 0.992: 1: 1 (molar ratio). Grade F), Si ₃ N ₄ (SN-E10 manufactured by Ube Industries), and Eu ₂ O ₃ (manufactured by Shin-Etsu Chemical Co., Ltd.) were weighed in an argon atmosphere and mixed using an alumina mortar. The obtained raw material mixture was filled into a boron nitride crucible and set in an atmosphere heating furnace. After the inside of the apparatus was evacuated to 1 × 10 ⁻² Pa, the evacuation was stopped, and the apparatus was filled with nitrogen up to 0.1 MPa, and then the temperature was raised to 1600 ° C. and held at 1600 ° C. for 5 hours. The obtained fired product was pulverized in an alumina mortar, and a phosphor having a particle size of 100 μm or less was collected to obtain a phosphor. The emission peak wavelength of this phosphor at an excitation wavelength of 465 nm was 648 nm.

(Measurement of chromaticity coordinates)
Chromaticity coordinates x and y in the XYZ color system defined by JIS Z8701 were calculated from data in the wavelength region of 480 nm to 800 nm of the emission spectrum.

(Calculation of the value of Formula [A])
The mass (g) of the firing container and the mass of the phosphor raw material (g) were measured and substituted into the following formula [A] to calculate the value of the formula [A].
(Mass of phosphor material) / {(Mass of firing container) + (Mass of phosphor material)} [A]

(Measurement of temperature change per minute in the heating process)
The temperature of the side wall of the firing container was measured using a tungsten-rhenium alloy thermocouple at intervals of 10 seconds. In addition, the thermometer was installed in the position of 1/2 height of the height filled with the phosphor raw material on the outer wall of the baking container. A change in temperature per minute was determined from the measured value obtained by the following formula [B].
Temperature change (° C./min)=temperature at time T minutes−temperature at time (T−1) minutes [B]

Example 1
(Manufacture of alloys)
Each raw metal was weighed so that the metal element composition ratio was Al: Si = 1: 1 (molar ratio), filled in a graphite crucible, and melted in an argon atmosphere using a high frequency induction melting furnace. . Thereafter, molten metal was poured from the crucible into the mold and solidified to obtain an alloy (mother alloy) having a metal element composition ratio of Al: Si = 1: 1.

  Subsequently, the mother alloy and other raw materials were weighed so that Eu: Sr: Ca: Al: Si = 0.008: 0.792: 0.2: 1: 1 (molar ratio). After evacuating the inside of the furnace, the evacuation was stopped, and the furnace was filled with argon to a predetermined pressure. In this furnace, the master alloy was melted using a calcia crucible, and then Sr, Eu, and Ca, which are raw materials, were added. After confirming that all the components were melted and the molten metal was agitated by the induced current, the molten metal was poured from a crucible into a water-cooled copper mold (plate shape with a thickness of 40 mm) and solidified.

The obtained plate-like alloy having a thickness of 40 mm was subjected to composition analysis by ICP method. About 10 g was sampled from one point near the center of gravity of the plate-like alloy and one point near the end face of the plate-like alloy, and elemental analysis was performed by ICP method.
Central part of plate-like alloy Eu: Sr: Ca: Al: Si = 0.009: 0.782: 0.212: 1: 0.986,
End face of plate-like alloy Eu: Sr: Ca: Al: Si = 0.000: 0.756: 0.210: 1: 0.962
The composition was substantially the same in the range of analysis accuracy. Therefore, it was considered that each element including Eu was distributed uniformly.

The obtained alloy showed a powder X-ray diffraction pattern similar to Sr (Si _0.5 Al _0.5 ) ₂ and was identified as an intermetallic compound called AlB ₂ type alkaline earth silicide.

(Crushing process)
The obtained alloy was pulverized using an alumina mortar in a nitrogen atmosphere until the particle size became about 1 mm or less. Using the supersonic jet pulverizer (Nippon Pneumatic Industrial Co., Ltd., PJM-80SP), the obtained alloy powder was pulverized in a nitrogen atmosphere (oxygen concentration 2% by volume), pulverization pressure 0.15 MPa, and raw material supply rate 0.8 kg. Crushed further at / hour.

When the weight median diameter D ₅₀ , QD and particle size distribution of the obtained alloy powder were measured, the weight median diameter D ₅₀ was 14.2 μm, the QD was 0.38, and the proportion of alloy particles of 10 μm or less was The ratio of alloy particles of 28.6% of the whole and 45 μm or more was 2.9%. The alloy powder had an oxygen content of 0.3% by weight and a nitrogen content of 0.3% by weight or less (below the detection limit).
Further, when the melting point of the obtained alloy powder was measured in an argon stream, the melting start temperature was around 1078 ° C. and the melting point was 1121 ° C.

(Primary nitriding process)
40 g of the obtained alloy powder was filled in a boron nitride crucible having an inner diameter of 54 mm, and a nitrogen-containing argon gas (nitrogen: argon = 2: 98 (volume ratio)) 2 L / min in a tubular electric furnace under normal pressure. From room temperature to 950 ° C., heating was performed at a rate of temperature increase of 4 ° C./min. From 950 ° C. to 1100 ° C., heating was performed at a rate of temperature increase of 2 ° C./min. Then, under a flow of nitrogen-containing argon gas (nitrogen: argon = 2: 98 (volume ratio)) 2 L / min, cool to 950 ° C. at 5 ° C./min, and then release to room temperature at about 10 ° C./min. Cooled to produce a nitrogen-containing alloy.

The obtained nitrogen-containing alloy was taken out and weighed. The weight increase rate was 4.5% by weight, and the total metal element content was 95.7% by weight. Furthermore, about the obtained nitrogen-containing alloy, the nitrogen content rate and the oxygen content rate were calculated | required by the above-mentioned method. The results are shown in Table 7.
Note that the temperature in the primary nitriding step of this example indicates the temperature in the furnace, that is, the temperature that can be set in the baking apparatus. The same applies to each of the following examples and comparative examples.

(Secondary nitriding process)
The nitrogen-containing alloy obtained in the primary nitriding step was pulverized using an alumina mortar in a nitrogen stream until the particle size became 53 μm or less, and the one that passed through a sieve having an opening of 53 μm was collected. The obtained alloy powder was filled in a boron nitride crucible having an inner diameter of 54 mm, and this was set in a hot isostatic press (HIP). The inside of the apparatus was evacuated to 5 × 10 ⁻¹ Pa, then heated to 300 ° C., and evacuation was continued at 300 ° C. for 1 hour. Thereafter, nitrogen was charged to 1 MPa and cooled to near room temperature. Thereafter, the operation of releasing the pressure to 0.1 MPa and refilling with nitrogen up to 1 MPa was repeated twice, and the pressure was adjusted to about 0.1 MPa before the start of heating. Subsequently, it heated at the temperature increase rate of 600 degreeC / hour until the furnace temperature became 950 degreeC. At this time, the internal pressure rose to about 0.5 MPa. The furnace was heated at a heating rate of 66.7 ° C./hour until the furnace temperature was changed from 950 ° C. to 1100 ° C., and held at 1100 ° C. for 30 minutes. Thereafter, while maintaining the temperature at 1100 ° C., the nitrogen pressure is increased to 140 MPa over about 3 hours, and then the furnace temperature is increased to 1900 ° C. and the furnace pressure is increased to 190 MPa over about 1 hour. The temperature and pressure were increased, and this state was maintained for 2 hours. Then, it cooled until it became 400 degrees C or less over 3 hours, and stood to cool. After 12 hours, a phosphor cooled to near room temperature was obtained. In addition, the temperature described above is a furnace temperature, that is, a temperature that can be set in a firing apparatus (in this example, HIP) (the following examples are also unless otherwise specified). The same shall apply).

The obtained phosphor was pulverized with an alumina mortar, and the emission characteristics (emission peak wavelength, relative emission peak intensity, relative luminance, and chromaticity coordinates) were measured. Table 9 shows the obtained results.
In this example, the value of the formula [A] was 0.50 (container mass 40 g, raw material mass 40 g), and the temperature change per minute in the heating step was 2 ° C./min or less.

Example 2
(Post-processing process)
The phosphor obtained in Example 1 was placed in 10 times the weight ratio of water at room temperature, stirred for 10 minutes using a stirrer, and dispersed. After standing for 1 hour, it was confirmed that the phosphor had settled, and the phosphor was separated by filtration. This operation was repeated 15 times. The resulting phosphor was dehydrated by performing suction filtration, and then placed in 10 times the amount of 0.5N hydrochloric acid by weight, and stirred and dispersed for 10 minutes using a stirrer. After allowing to stand for 1 hour, the phosphor was separated by filtration, and further dispersed three times in a weight ratio of water and filtered three times. When the electrical conductivity was measured as described above, the electrical conductivity of the supernatant liquid was 1.90 mS / m. After dehydration, it was dried at 120 ° C. for 12 hours to obtain a phosphor.
Measurement of the weight-average median diameter _{D 50} of the obtained phosphor was 12.7 [mu] m. The emission characteristics of the obtained phosphor were measured. The results are shown in Table 9. It can be seen that the relative emission peak intensity and the relative luminance are improved by subjecting the phosphor obtained in Example 1 to the cleaning treatment. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 3
The heating conditions for the primary nitriding step were the same as in Example 1 except that the maximum temperature reached 1050 ° C. and the holding time at the maximum temperature was 10 hours. With respect to the obtained nitrogen-containing alloy, the weight increase rate and the total metal element content were calculated, and the results are shown in Table 7.
Subsequently, a secondary nitriding step was performed in the same manner as in Example 1 to obtain a phosphor. The emission characteristics of the obtained phosphor were measured. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 4
The phosphor obtained in Example 3 was washed 15 times with water and once with 0.5N hydrochloric acid in the same manner as in Example 2. Subsequently, the supernatant was washed 5 times with water until the electrical conductivity of the supernatant reached 1.52 mS / m. Thereafter, classification was performed to obtain a phosphor having a particle size range of 3 μm to 30 μm.
Measurement of the weight-average median diameter D ₅₀ of the obtained phosphor was 7.7 .mu.m. The emission characteristics of the obtained phosphor were measured. The results are shown in Table 9. It can be seen that the obtained phosphor has improved relative emission peak intensity and relative luminance as compared with the phosphor obtained in Example 3. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 5
A nitrogen-containing alloy was produced in the same manner as in Example 3 except that in the primary nitriding step, the heating atmosphere was a nitrogen-containing argon gas (nitrogen: argon = 7: 93 (volume ratio)) 2 L / min. For the obtained nitrogen-containing alloy, the weight increase rate and the total metal element content were determined. The results are shown in Table 7. Compared to Example 3, it can be seen that increasing the nitrogen concentration in the furnace increases the weight increase rate and decreases the total metal element content.
Subsequently, a secondary nitriding step was performed in the same manner as in Example 1 to obtain a phosphor. The emission characteristics of the obtained phosphor were measured. The results are shown in Table 9. It can be seen that the light emission characteristics are improved as compared with the phosphor obtained in Example 3. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 6
A nitrogen-containing alloy was produced in the same manner as in Example 3 except that in the primary nitriding step, the heating atmosphere was a nitrogen-containing argon gas (nitrogen: argon = 4: 96 (volume ratio)) 2 L / min. For the obtained nitrogen-containing alloy, the weight increase rate and the total metal element content were determined. The results are shown in Table 7.
Subsequently, a secondary nitriding step was performed in the same manner as in Example 1 to obtain a phosphor. The emission characteristics of the obtained phosphor were measured. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 7
In the primary nitriding step, the heating atmosphere was nitrogen-containing argon gas (nitrogen: argon = 5: 95 (volume ratio)) at a flow rate of 2 L / min, except that the holding time at the highest temperature (1050 ° C.) was 5 hours. A nitrogen-containing alloy was produced in the same manner as in Example 3. With respect to the obtained nitrogen-containing alloy, the weight increase rate and the total metal element content were calculated, and the results are shown in Table 7.
Subsequently, a secondary nitriding step was performed in the same manner as in Example 1 to obtain a phosphor. The emission characteristics of the obtained phosphor were measured. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 8
A phosphor was manufactured in the same manner as in Example 3 except that in the primary nitriding step, the heating atmosphere was under a nitrogen-containing argon gas (nitrogen: argon = 5: 95 (volume ratio)) flow rate of 2 L / min. For the obtained nitrogen-containing alloy, the weight increase rate and the total metal element content were determined. The results are shown in Table 7.
Subsequently, a secondary nitriding step was performed in the same manner as in Example 1 to obtain a phosphor. The emission characteristics of the obtained phosphor were measured. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 9
Using the alloy powder produced in the same manner as in Example 1, the primary nitriding step was performed under the following conditions. 40 g of the alloy powder was filled in a boron nitride crucible having an inner diameter of 54 mm, and heated from room temperature to 900 ° C. in a vacuum at a temperature rising rate of 20 ° C./min using an atmosphere firing furnace. At 900 ° C., nitrogen-containing argon gas (nitrogen: argon = 5: 95 (volume ratio)) was filled to 0.01 MPa with a gauge pressure. While maintaining this pressure, the temperature was increased from 900 ° C. to 1050 ° C. at a rate of 2 ° C./min under a flow of nitrogen-containing argon gas (nitrogen: argon = 5: 95 (volume ratio)) of 1 L / min. The temperature was maintained at 1050 ° C. for 4 hours. Subsequently, after cooling to 200 degrees C or less over about 2 hours, it stood to cool to room temperature, and manufactured the nitrogen containing alloy. With respect to the obtained nitrogen-containing alloy, the weight increase rate and the total metal element content were calculated, and the results are shown in Table 7.
Subsequently, a secondary nitriding step was performed in the same manner as in Example 1 to obtain a phosphor. The emission characteristics of the obtained phosphor were measured. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 10
In the primary nitriding step, a nitrogen-containing alloy was manufactured in the same manner as in Example 1 except that the heating atmosphere was a nitrogen stream, the maximum temperature reached was 1030 ° C., and the holding time at the maximum temperature was 8 hours.
The obtained nitrogen-containing alloy was analyzed for nitrogen / oxygen content. As a result, the nitrogen content was 1.10% by weight and the oxygen content was 1.66% by weight. The weight increase rate was about 3% by weight, and the total metal element content was 97% by weight.
Further, from the analysis result of the nitrogen / oxygen content and the ICP method analysis result, the elemental composition ratio of the obtained nitrogen-containing alloy is Al: Si: Ca: Sr: Eu: N: O = 1: 0. 922: 0.214: 0.734: 0.008: 0.11: 0.14.
The obtained nitrogen-containing alloy was subjected to a secondary nitriding step in the same manner as in Example 1 to produce a phosphor.
In addition, the emission characteristics of the obtained phosphor were also measured. The results are shown in Table 9.
Next, the obtained phosphor was washed in the same manner as in Example 4, and then the oxygen content, nitrogen content, and NI / NP were determined. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 11
The phosphor was prepared in the same manner as in Example 1 except that the primary nitriding step was performed on the alloy powder obtained in Example 1 under the following conditions and that the pulverization treatment was not performed after the primary nitriding step. Manufactured.
The entire atmosphere in the rotary kiln was replaced with argon, and an alumina core tube having a diameter of 90 mm and a total length of 1500 mm was set at an inclination angle of 1.9 °. While rotating the core tube at 5 rpm in a mixed gas flow containing nitrogen (0.7 L / min), hydrogen (0.2 L / min), and argon (5 L / min) in a countercurrent direction with respect to the core tube The alloy powder was continuously supplied at 400 g / hour using a screw feeder. The heater temperature was 1100 ° C. At this time, the soaking zone of the alloy powder (in this case, about 150 mm in the central portion of the core tube) residence time was 3 minutes. The nitrogen-containing alloy after the completion of the primary nitriding step that came out of the furnace core tube was recovered in a container in which the atmosphere was replaced with argon, and then rapidly cooled to confirm that it was powdery.
The obtained nitrogen-containing alloy was analyzed for nitrogen and oxygen content. As a result, the nitrogen content was 3.7% by weight and the oxygen content was 1.2% by weight.
Moreover, the powder X-ray diffraction pattern of the obtained nitrogen-containing alloy is shown in FIG. A powder X-ray diffraction pattern similar to Sr (Si _0.5 Al _0.5 ) ₂ , which is one of the intermetallic compounds called AlB ₂ type alkaline earth silicide, is the main phase. In addition, SrSi (PDF No. 16-0008), SrSi ₂ (PDF No. 19-1285) and other intermetallic compounds were detected.
Subsequently, the obtained nitrogen-containing alloy was subjected to a secondary nitriding step in the same manner as in Example 1 to produce a phosphor. The obtained phosphor was measured for light emission characteristics, and the results are shown in Table 9.
Further, the obtained phosphor was washed in the same manner as in Example 2, and then the oxygen content and the nitrogen content were determined. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 12
40 g of the alloy powder obtained in Example 1 was placed in a boron nitride crucible having an inner diameter of 54 mm, and a primary nitriding step was performed using an atmosphere firing furnace. The inside of the furnace was evacuated and heated from room temperature to 900 ° C. at a heating rate of 20 ° C./min. Subsequently, nitrogen-containing argon gas (nitrogen: argon = 5: 95 (volume ratio)) was filled to a gauge pressure of 0.01 MPa. While maintaining pressure, nitrogen-containing argon gas (nitrogen: argon = 5: 95 (volume ratio)) was heated from 900 ° C. to 1050 ° C. at a heating rate of 2 ° C./min under a flow of 1 L / min. Held for hours. Subsequently, after cooling to 900 ° C., the atmosphere gas was replaced with nitrogen, and heating was performed from 900 ° C. to 1050 ° C. at a rate of temperature increase of 2 ° C./min, and held at 1050 ° C. for 4 hours. The sample was cooled for about 2 hours until the sample temperature reached 200 ° C., and allowed to cool to near room temperature.
The oxygen content and nitrogen content of the obtained nitrogen-containing alloy were calculated, and the results are shown in Table 7.
Moreover, the powder X-ray diffraction pattern of the obtained nitrogen-containing alloy is shown in FIG. In the powder X-ray diffraction pattern, a phase similar to Sr (Si _0.5 Al _0.5 ) ₂ is present together with intermetallic compounds such as SrSi (PDF No. 16-0008) and SrSi ₂ (No. 19-1285). was detected.
Subsequently, the obtained nitrogen-containing alloy was subjected to a secondary nitriding step in the same manner as in Example 1 except that the temperature range from room temperature to 1900 ° C. was increased at 600 ° C./hour, and further in the same manner as in Example 4. Cleaning treatment and classification treatment were performed. The obtained phosphor was measured for light emission characteristics, and the results are shown in Table 9. Further, the oxygen content, nitrogen content, and NI / NP were determined, and the results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step. Further, FIG. 11 shows a powder X-ray diffraction pattern of the obtained phosphor.

Example 13
40 g of the alloy powder obtained in Example 1 was placed in a boron nitride crucible having an inner diameter of 54 mm, and a primary nitriding step was performed using an atmosphere firing furnace. The mixture was heated from room temperature to 900 ° C. in vacuum at a heating rate of 20 ° C./min, and at 900 ° C., nitrogen-containing argon gas (nitrogen: argon = 5: 95 (volume ratio)) was filled to 0.01 MPa with a gauge pressure. While maintaining pressure, nitrogen-containing argon gas (nitrogen: argon = 5: 95 (volume ratio)) was heated from 900 ° C. to 1050 ° C. at a heating rate of 2 ° C./min under a flow of 1 L / min. Held for hours. Thereafter, the mixture was allowed to cool to room temperature, and again heated from 900 ° C. to 1050 ° C. at a heating rate of 2 ° C./min under a flow of nitrogen-containing argon gas (nitrogen: argon = 5: 95 (volume ratio)) 1 L / min Hold at 3 ° C. for 3 hours. Then, it cooled to room temperature, substituted atmospheric gas with nitrogen, heated from 900 degreeC to 1050 degreeC with the temperature increase rate of 2 degree-C / min, and hold | maintained at 1050 degreeC for 3 hours. The mixture was cooled to 200 ° C. over about 2 hours and allowed to cool to near room temperature.
The oxygen content and nitrogen content of the obtained nitrogen-containing alloy were calculated, and the results are shown in Table 7.
Moreover, the powder X-ray-diffraction pattern of the obtained nitrogen-containing alloy is shown in FIG. In the powder X-ray diffraction pattern, intermetallic compounds such as SrSi (PDF No. 16-0008) and SrSi ₂ (PDF No. 19-1285) were detected.
A secondary nitriding step was performed in the same manner as in Example 1 except that 142 g of the obtained nitrogen-containing alloy was filled in a crucible made of boron nitride having a diameter of 85 mm and heated from room temperature to 1900 ° C. at a heating rate of 600 ° C./hour. Further, cleaning treatment and classification treatment were performed in the same manner as in Example 4. The emission characteristics of the obtained phosphor were measured. The results are shown in Table 9. Moreover, oxygen content rate, nitrogen content rate, and NI / NP were calculated | required. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step. The powder X-ray diffraction pattern of the obtained phosphor is shown in FIG.

Example 14
The phosphor was prepared in the same manner as in Example 1 except that the primary nitriding step was performed on the alloy powder obtained in Example 1 under the following conditions and that the pulverization treatment was not performed after the primary nitriding step. Manufactured.
After the entire atmosphere rotary kiln is evacuated, gas replacement is performed by introducing a mixed gas of nitrogen (2.5 L / min) and argon (2.5 L / min), and the diameter is 90 mm and the total length is 1500 mm. The furnace tube was set at an inclination angle of 1.9 °. The heater temperature was set to 1100 ° C. While rotating the core tube at 5 rpm in a mixed gas flow containing nitrogen (0.7 L / min), hydrogen (0.2 L / min), and argon (5 L / min) in a countercurrent direction with respect to the core tube The alloy powder was continuously supplied at 220 g / hour using a screw feeder. At this time, the soaking time of the alloy powder in the soaking zone (the time from the start of feeding to the beginning of discharging × the soaking zone length / the total length of the core tube) was about 3 minutes. The nitrogen-containing alloy after the completion of the primary nitriding step that emerged from the core tube was collected in a container whose atmosphere was replaced with argon, and rapidly cooled.
When the nitrogen-containing alloy after the completion of the primary nitriding step was analyzed, the nitrogen content was 8.9% by weight and the oxygen content was 2.9% by weight.
Moreover, the powder X-ray-diffraction pattern of the obtained nitrogen-containing alloy is shown in FIG. FIG. 9 shows that intermetallic compounds such as SrSi (PDF No. 16-0008) and SrSi ₂ (PDF No. 19-1285) were detected.
Subsequently, a secondary nitriding step was performed on the obtained nitrogen-containing alloy under the following conditions. The inside of the HIP was evacuated to 5 × 10 ⁻¹ Pa, heated to 300 ° C., and evacuation was continued at 300 ° C. for 1 hour. Thereafter, the pressure was increased to about 49 MPa in nitrogen atmosphere at room temperature. Next, heating was performed at a temperature rising rate of 600 ° C./hour until reaching 900 ° C., and heating was performed at a temperature rising rate of 66.7 ° C./hour until reaching 1100 ° C. At this time, the pressure was about 140 MPa. Thereafter, the temperature inside the furnace was raised to 1900 ° C. and the internal pressure was raised to 190 MPa over about 1.5 hours, and this state was maintained for 1 hour, followed by cooling to room temperature to obtain a phosphor. The obtained phosphor was pulverized to 50 μm or less in an alumina mortar, and the luminescent properties were measured. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step. Moreover, after performing the washing | cleaning process of the fluorescent substance similarly to Example 2, it analyzed and calculated | required oxygen content rate, nitrogen content rate, and NI / NP. The results are shown in Table 9.

Example 15
After completion of the primary nitriding step, the obtained nitrogen-containing alloy was pulverized using an alumina mortar in a nitrogen atmosphere, and passed through a sieve having an aperture of 53 μm in a nitrogen atmosphere, as in Example 14. A secondary nitriding step was performed to manufacture a phosphor.
With respect to the obtained phosphor, emission characteristics were measured in the same manner as in Example 14. The results are shown in Table 9. Moreover, after performing the washing | cleaning process of the fluorescent substance similarly to Example 2, it analyzed and calculated | required oxygen content rate, nitrogen content rate, and NI / NP. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 16
Other than that the supply rate of the alloy powder was 71 g / hr, under a mixed gas flow containing nitrogen (0.25 L / min) and argon (5 L / min), and the heater temperature was 1080 ° C. In the same manner as in Example 14, the primary nitriding step was performed. At this time, the soaking time of the alloy powder in the soaking zone (the time from the start of feeding to the beginning of discharging × the soaking zone length / the total length of the core tube) was about 3 minutes. The nitrogen-containing alloy after the completion of the primary nitriding step that emerged from the core tube was collected in a container whose atmosphere was replaced with argon, and rapidly cooled.
When the nitrogen-containing alloy after the completion of the primary nitriding step was analyzed, the nitrogen content was 5.5% by weight and the oxygen content was 2.8% by weight.
The nitrogen-containing alloy was subjected to secondary nitriding treatment in the same manner as in Example 14 to produce a phosphor. The light emission characteristics were measured in the same manner as in Example 14. The results are shown in Table 9. Moreover, after performing the washing | cleaning process of the fluorescent substance similarly to Example 2, it analyzed and calculated | required oxygen content rate, nitrogen content rate, and NI / NP. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 17
While flowing a mixed gas of nitrogen (2.5 L / min) and argon (2.5 L / min) through the entire atmosphere rotary kiln, nitrogen (2.5 L / min) was further introduced into the reactor core tube from the bottom of the inclined reactor core tube. Min), argon (2.5 L / min), mixed gas of hydrogen (0.2 L / min) was supplied, and the supply rate of the alloy powder was 0.3 kg / hr, as in Example 14. The primary nitriding step was performed under the conditions described above.
When the nitrogen-containing alloy after the completion of the primary nitriding step was analyzed, the nitrogen content was 14.4% by weight and the oxygen content was 2.2% by weight.
Subsequently, the obtained nitrogen-containing alloy was pulverized in the same manner as in Example 1. The weight median diameter D ₅₀ of the obtained alloy powder is 11.4 μm, the proportion of alloy particles of 45 μm or more is 1% or less, the proportion of particles of 100 μm or more is less than 0.1%, the proportion of alloy particles of 5 μm or less Was 12% and QD was 0.36.
The nitrogen-containing alloy thus obtained was nitrided under the same conditions as in Example 14, and the emission characteristics were measured in the same manner as in Example 14. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.

Example 18
A phosphor was produced under the same conditions as in Example 17 except that the value of the formula [A] was 0.50 (the filling rate of the phosphor material in the firing container was 35% by volume). The emission characteristics of the obtained phosphor were measured in the same manner as in Example 17. The results are shown in Table 9.

Example 19
The nitrogen-containing alloy after completion of the primary nitriding step obtained in Example 17 was pulverized to 500 μm or less using an alumina mortar. Next, using a jet mill (Sanrex Kogyo Nano Grinding Mill NJ-50) lined with zirconia in the pulverization section, in a nitrogen atmosphere (oxygen concentration of 1% by volume or less), pulverization pressure 0.3 MPa, raw material supply rate It grind | pulverized at 0.3 kg / h. When the obtained alloy powder was passed through a sieve having an aperture of 53 μm, an alloy powder having a weight median diameter D ₅₀ of 12.8 μm and having a particle size distribution peak in the vicinity of 20 μm was obtained. The ratio of alloy particles of 45 μm or more in the obtained alloy powder was 6%, the ratio of alloy particles of 5 μm or less was 18%, and the QD was 0.60.
The nitrogen-containing alloy thus obtained was nitrided under the same conditions as in Example 14 to obtain a phosphor (however, the filling rate of the phosphor raw material in the firing container was 26% by volume). The emission characteristics of the obtained phosphor were measured in the same manner as in Example 14. The results are shown in Table 9. Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step.
Further, 10.16 mg of the obtained nitrogen-containing alloy was placed in a boron nitride container and heated from room temperature to 1300 ° C. at a heating rate of 10 ° C./min under a flow of nitrogen gas of 100 ml / min. The above-mentioned TG-DTA measurement was performed, and the weight change during temperature rising was investigated. The result is shown in FIG.

  Here, when Example 17 and Example 19 are compared, Example 17 has a smaller QD and the emission peak intensity of the obtained phosphor is superior to Example 17. Accordingly, it can be seen that it is more preferable that the particle size distribution of the alloy powder before the start of the secondary nitriding process is sharp because the light emission characteristics tend to be improved.

Comparative Example 1
Except that the primary nitriding step was not performed, production of the phosphor was attempted in the same manner as in Example 1, and a black lump was obtained. As a result of measuring the light emission characteristics of this alloy lump in the same manner as in Example 1, no light emission was observed. About the obtained molten alloy lump, nitrogen content rate, oxygen content rate, total metal element content rate, etc. were measured. The results are shown in Tables 7 and 9.

Further, 13 mg of the alloy powder before primary nitriding obtained in the pulverization step of Example 1 was put in a boron nitride container, and the temperature was increased from room temperature to 1300 ° C. under a nitrogen gas flow of 100 ml / min at a heating rate of 10 ° C./min. TG-DTA measurement was performed by heating. As a result, at 1090 ° C. to 1100 ° C., heat generation occurred and the weight increased. FIG. 10 shows the weight change rate during the TG-DTA measurement. From FIG. 10, it can be seen that the weight increased momentarily around 113 minutes (around 1100 ° C.) after the start of heating. The rate of weight increase at this peak (around 1100 ° C.) was 1628% / hour.
Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step. Compared with the examples, in this comparative example, the temperature change per minute is very large, and it is estimated that a rapid exothermic reaction occurred in the furnace.
From these facts, it is considered that in Comparative Example 1, the alloy powder instantaneously melted due to rapid heat generation, the specific surface area decreased, and nitriding did not proceed.

Comparative Example 2
A nitrogen-containing alloy was produced in the same manner as in Example 1 except that the primary nitriding step was performed in a nitrogen stream at 1030 ° C. for 2 hours. The obtained nitrogen-containing alloy was analyzed for nitrogen content and oxygen content. As a result, the nitrogen content was 0.64% by weight and the oxygen content was 1.39% by weight. Moreover, it calculated also about the weight increase rate and the total metal element content rate. The results are shown in Table 7.
The obtained nitrogen-containing alloy was subjected to a secondary nitriding step in the same manner as in Example 1 to attempt to produce a phosphor, and the emission characteristics were evaluated in the same manner as in Example 1. However, no emission was observed. The results are shown in Table 9. The phosphor obtained had a nitrogen content of 22% by weight.
Table 8 shows the value of the formula [A] and the temperature change per minute in the heating step. Compared with the examples, in this comparative example, the temperature change per minute is very large, and it is estimated that a rapid exothermic reaction occurred in the furnace.
In Comparative Example 2, since the temperature of the primary nitriding process was low and the time was short, the nitriding reaction did not proceed sufficiently in the primary nitriding process, and thus the speed of the nitriding reaction in the secondary nitriding process could not be controlled appropriately. It is considered that the light emission characteristics are deteriorated. Therefore, in order to obtain a phosphor with high characteristics, it is considered necessary to perform the primary nitriding step under appropriate conditions.

Example 20
As the red phosphor, the phosphor (Sr _0.792 Ca _0.2 AlSiN ₃ : Eu _0.008 ) obtained in Example 1, and as the green phosphor, CaSc ₂ O ₄ : Ce _0.01 (hereinafter, A white light-emitting device having the configuration shown in FIG. 2B was manufactured by the following procedure using the phosphor (A).

  As a 1st light-emitting body, blue LED [22] (C460-EZ by a Cree company) light-emitted with a wavelength of 455 nm-460 nm was used. This blue LED [22] was die-bonded to the electrode [27] at the bottom of the recess of the frame [24] using a silver paste as an adhesive. Next, using a gold wire with a diameter of 25 μm as the wire [25], the blue LED [22] and the electrode [26] of the frame [24] were connected.

A phosphor mixture of the above-mentioned two types of phosphors (red phosphor and green phosphor) and a silicone resin (JCR6101UP manufactured by Toray Dow Co., Ltd.), and the content of each phosphor in the phosphor-silicone resin mixture is red fluorescent The phosphor-silicone resin mixture (phosphor-containing composition) was mixed well so that the ratio of 0.8% by weight of the phosphor and 6.2% by weight of the green phosphor was obtained. Injected into.
This was held at 150 ° C. for 2 hours to cure the silicone resin, thereby forming a phosphor-containing part [23] to obtain a surface-mounted white light emitting device. In the description of the present embodiment, the reference numerals of the parts corresponding to FIG.

When the obtained surface-mounted light-emitting device was driven by applying a current of 20 mA to the blue LED [22] to emit light, white light was obtained in any of the light-emitting devices of the examples.
The emission spectrum of the obtained surface-mounted white light-emitting device was measured. The result is shown in FIG. Table 10 shows values of various emission characteristics (total luminous flux, light output, chromaticity coordinates, color temperature, color deviation, color rendering index) calculated from the obtained emission spectrum. In Table 10, Tcp represents the correlated color temperature (unit K), and Duv represents the color deviation.
Thus, by using the phosphor of the present invention in combination with an arbitrary green phosphor, a light emitting device with high color rendering properties can be obtained.

It is a typical perspective view which shows one Example of the light-emitting device of this invention. FIG. 2A is a schematic cross-sectional view showing an embodiment of a bullet-type light emitting device of the present invention, and FIG. 2B is a schematic view showing an embodiment of the surface-mounted light-emitting device of the present invention. It is sectional drawing. It is typical sectional drawing which shows one Example of the illuminating device of this invention. It is a schematic diagram which shows the gas atomizer suitable for refinement | miniaturization and solidification of a molten alloy. 10 is a chart showing a TG-DTA analysis result of the nitrogen-containing alloy obtained in Example 19. 10 is a chart showing a powder X-ray diffraction pattern of the nitrogen-containing alloy obtained in Example 11. 10 is a chart showing a powder X-ray diffraction pattern of the nitrogen-containing alloy obtained in Example 12. 10 is a chart showing a powder X-ray diffraction pattern of the nitrogen-containing alloy obtained in Example 13. 14 is a chart showing a powder X-ray diffraction pattern of the nitrogen-containing alloy obtained in Example 14. 6 is a chart showing a TG-DTA analysis result of an alloy powder before primary nitriding in Comparative Example 1. 10 is a chart showing a powder X-ray diffraction pattern of the phosphor obtained in Example 12. 10 is a chart showing a powder X-ray diffraction pattern of the phosphor obtained in Example 13. 22 is a chart showing an emission spectrum of the surface mount light emitting device obtained in Example 20. FIG.

Explanation of symbols

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)
8 Phosphor-containing resin part 9 Conductive wire 10 Mold member 11 Surface emitting illumination device 12 Holding case 13 Light emitting device 14 Diffusion plate 22 Excitation light source (first light emitter) (LED)
23 Phosphor-containing part (second light emitter)
24 frame 25 conductive wire 26 electrode 27 electrode 101 melting chamber 102 induction coil 103 crucible 104 injection nozzle 105 injection chamber 106 recovery chamber 107 cyclone

Claims (8)

A method for producing a nitride or oxynitride phosphor comprising a step of heating a phosphor material in a nitrogen-containing atmosphere,
As a part or all of the phosphor raw material, an alloy having two or more metal elements constituting the phosphor (hereinafter referred to as “phosphor raw material alloy”) is used.
In the heating step, heating under a condition that a temperature change per minute in a temperature range from a temperature lower than the melting point of the phosphor raw material alloy by 100 ° C. to a temperature lower than the melting point by 30 ° C. is within 50 ° C. The method for producing a phosphor characterized by satisfying the following 1).
1) A part or all of the phosphor raw material alloy is a nitrogen-containing alloy having a total metal element content of 97% by weight or less and a nitrogen content of 0.8% by weight or more and 27% by weight or less. The phosphor is a phosphor represented by the following general formula [1], and in the following general formula [1]:
M ¹ Is one or more elements selected from the group consisting of Cr, Mn, Fe, Ce, Pr, Nd, Sm, Eu, Tb, Dy, Ho, Er, Tm, and Yb,
M ² Is one or more elements selected from the group consisting of Mg, Ca, Sr, Ba, and Zn,
M ³ Is one or more elements selected from the group consisting of Al, Ga, In, and Sc,
M ⁴ 2. The method for producing a phosphor according to claim 1, wherein is one or more elements selected from the group consisting of Si, Ge, Sn, Ti, Zr, and Hf.
M ¹ _a M ² _b M ³ _c M ⁴ _d N _e O _f [1]
(However, a, b, c, d, e, and f are values in the following ranges, respectively.
0.00001 ≦ a ≦ 0.15
a + b = 1
0.5 ≦ c ≦ 1.5
0.5 ≦ d ≦ 1.5
2.5 ≦ e ≦ 3.5
0 ≦ f ≦ 0.5 ) The method for producing a phosphor according to claim 1 or 2, wherein any one of the following 2) to 4) is satisfied.
2) The rate of temperature increase in the temperature range from a temperature lower than the melting point of the phosphor raw material alloy by 100 ° C. to a temperature lower than the melting point by 30 ° C. is 9 ° C./min or less. 3) As the phosphor raw material, the phosphor A nitride or oxynitride containing one or more metal elements constituting the phosphor is used together with the raw material alloy. 4) The phosphor having an angle of repose of 45 degrees or less as the phosphor raw material alloy. Use alloy powder for raw materials In the heating step, the phosphor material is heated in a firing container, and the ratio of the weight of the phosphor material to the weight of the firing container represented by the following formula [A] is 0.1 or more. The method for producing a phosphor according to any one of claims 1 to 3, wherein:
(Mass of phosphor material) / {(Mass of firing container) + (Mass of phosphor material)} [A] The method for producing a phosphor according to any one of claims 1 to 4 , wherein the nitrogen-containing alloy satisfies the following formula [7].
0.03 ≦ NI / NP ≦ 0.9 [7]
(In Formula [7],
NI represents the nitrogen content (% by weight) of the nitrogen-containing alloy,
NP represents the nitrogen content (% by weight) of the phosphor to be produced. ) The step of heating the nitrogen-containing alloy as part or all of the phosphor raw material in a nitrogen-containing atmosphere (hereinafter referred to as “secondary nitriding step”) at a temperature higher by 300 ° C. or more than the melting point of the nitrogen-containing alloy. the method for producing a phosphor according to any one of claims 1 to 5, characterized in that the step of heating. The fluorescence according to any one of claims 1 to 6 , further comprising a step of cooling the nitrogen-containing alloy to a temperature lower than the melting point of the nitrogen-containing alloy by 100 ° C or more prior to the secondary nitriding step. Body manufacturing method. The method for producing a phosphor according to any one of claims 1 to 7 , further comprising a step of pulverizing the nitrogen-containing alloy prior to the secondary nitriding step.

Images