JP2017155217A - Phosphor, light-emitting device and manufacturing method of phosphor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of alkali earth metal aluminate phosphor excellent in moisture resistance.SOLUTION: There is provided a manufacturing method of a phosphor including preparing phosphor particles containing alkali earth aluminate having a composition represented by the following formula (1), contacting the prepared phosphor particles with a liquid medium containing water, obtaining purified phosphor particles by removing at least a part of the contacted liquid medium, obtaining phosphate compound attached phosphor particles by attaching a phosphate compound to a surface of the purified phosphor particles and heat treating the phosphate compound attached phosphor particles at 500°C to 700°C. (Sr,Eu)AlO(1), where x satisfies 0.05≤x≤0.4 and a part of Sr may be substituted by at least one element selected from Mg, Ca, Ba and Zn.SELECTED DRAWING: Figure 6

Description

  The present disclosure relates to a phosphor, a light emitting device, and a method for manufacturing the phosphor.

  By combining a light source and a wavelength conversion member that can be excited by light from this light source and emit light of a hue different from the hue of the light source, light of various hues can be emitted according to the principle of light color mixing Light emitting devices have been developed. In particular, light emitting devices formed by combining light emitting diodes (hereinafter referred to as “LEDs”) and phosphors are actively applied to backlights, lighting devices, and the like of liquid crystal display devices.

  As such a phosphor, an alkaline earth metal aluminate phosphor that emits light from blue-green to green is known, and a light-emitting device using the same is proposed (for example, see Patent Document 1).

JP 2002-171000 A

  However, alkaline earth metal aluminate phosphors have the problem of being degraded by hydrolysis when exposed to moisture. Then, one embodiment concerning this indication makes it a subject to provide a manufacturing method of alkaline earth metal aluminate fluorescent substance excellent in moisture resistance.

Specific means for solving the above problems are as follows, and the present invention includes the following aspects.
A first aspect of the present disclosure is to prepare phosphor particles containing an alkaline earth metal aluminate having a composition represented by the following formula (1), and to prepare the phosphor particles as a liquid medium containing water Contacting with the liquid, obtaining at least a part of the contacted liquid medium to obtain a purified phosphor particle, and attaching a phosphate compound to the surface of the purified phosphor particle to form a phosphate compound It is a method for producing a phosphor comprising obtaining attached phosphor particles and heat-treating the phosphoric acid compound-attached phosphor particles at 500 ° C. or more and 700 ° C. or less.
(Sr _1-x , Eu _x ) ₄ Al ₁₄ O ₂₅ (1)
In the formula (1), x satisfies 0.05 ≦ x ≦ 0.4, and a part of Sr is substituted with at least one element selected from the group consisting of Mg, Ca, Ba and Zn. Also good.

  A second aspect of the present disclosure includes phosphor particles containing an alkaline earth metal aluminate and a phosphoric acid compound disposed on the surface of the phosphor particles. In differential scanning calorimetry, 25 ° C. to 650 ° C. Is a phosphor having an endothermic amount of 50 J / g or less.

  A third aspect of the present disclosure includes the phosphor and a light emitting element having an emission peak wavelength in a wavelength range of 380 nm or more and 470 nm or less, and in an emission spectrum, the emission intensity at an emission peak wavelength of the phosphor The light-emitting device has a light emission intensity ratio at a light emission peak wavelength of the light-emitting element of 10 or less.

  According to one embodiment of the present disclosure, a method for producing an alkaline earth metal aluminate phosphor having excellent moisture resistance can be provided.

It is a schematic sectional drawing which shows an example of the light-emitting device which concerns on this embodiment. It is a schematic sectional drawing which shows another example of the light-emitting device which concerns on this embodiment. It is a figure which shows an example of the SEM image of a fluorescent substance particle. It is a figure which shows an example of the SEM image of the phosphoric acid compound adhesion fluorescent substance particle which is not heat-processed. It is a figure which shows an example of the SEM image of the fluorescent substance after heat-processing at 400 degreeC. It is a figure which shows an example of the SEM image of the fluorescent substance after heat-processing at 600 degreeC. It is a figure which shows the influence which heat processing temperature has on an excitation spectrum. It is a figure which illustrates the emission spectrum which shows the relative intensity with respect to the wavelength of a light-emitting device. It is a figure which shows an example of the DSC curve which shows the emitted-heat amount with respect to the temperature of the phosphoric acid compound adhesion fluorescent substance particle which is not heat-processed. It is a figure which shows an example of the DSC curve which shows the emitted-heat amount with respect to the temperature of the fluorescent substance after heat processing. It is a figure which illustrates the spectrum which shows the light intensity with respect to a wavelength about various light sources. It is a figure which illustrates the spectrum which shows the light intensity with respect to the wavelength in seawater about various light sources.

  Hereinafter, the phosphor manufacturing method, the phosphor, and the light emitting device according to the present disclosure will be described. However, the embodiment described below is for embodying the technical idea of the present invention, and the present invention is not limited to the following. In this specification, the relationship between color names and chromaticity coordinates, the relationship between the wavelength range of light and the color name of monochromatic light, and the like are in accordance with JIS Z8110. The content of each component in the composition means the total amount of the plurality of substances present in the composition unless there is a specific notice when there are a plurality of substances corresponding to each component in the composition. The average particle diameter of the phosphor is a numerical value called “Fisher Sub Sieve Sizer's No.” and is measured using an air permeation method. The volume median diameter (Dm) of the phosphor is measured by a pore electrical resistance method based on the Coulter principle. Specifically, the particle size distribution is measured using a particle size distribution measuring apparatus (for example, Multisizer manufactured by Beckman Coulter, Inc.), and the volume median diameter (Dm) is obtained as the particle diameter corresponding to 50% of the cumulative volume from the small diameter side. .

[Phosphor production method]
The method for producing a phosphor according to the present embodiment includes preparing phosphor particles containing an alkaline earth metal aluminate having a specific composition, and purifying the prepared phosphor particles by purifying the prepared phosphor particles. Obtaining a phosphoric acid compound-attached phosphor particle by attaching a phosphoric acid compound to the surface of the purified phosphor particle; and heating the phosphoric acid compound-attached phosphor particle to a temperature of 500 ° C. to 700 ° C. Heat-treating with. The phosphor obtained by the manufacturing method of the present embodiment has a phosphoric acid compound that has been heat-treated at a specific temperature on the surface of phosphor particles containing alkaline earth metal aluminate, and has excellent moisture resistance. .

Alkaline earth metal aluminate The alkaline earth metal aluminate contained in the phosphor particles is excited by light of at least 220 nm to 470 nm and emits light having an emission peak wavelength in the range of 440 nm to 530 nm. Examples of the alkaline earth metal aluminate include a fluorescent compound having a composition represented by the following formula, and at least one selected from the group consisting of these is preferable.
(Sr _1-x , Eu _x ) ₄ Al ₁₄ O ₂₅ (1)
(Wherein x satisfies 0.05 ≦ x ≦ 0.4, and part of Sr may be substituted with at least one element selected from the group consisting of Mg, Ca, Ba and Zn)
(Sr _1-xy , Eu _x , Dy _y ) ₄ Al ₁₄ O ₂₅ (2)
(Wherein x + y satisfies 0.05 <x + y <0.4, and a part of Sr may be substituted with at least one element selected from the group consisting of Mg, Ca, Ba and Zn)
(Sr _1-x , Eu _x ) Al ₂ O ₄ (3)
(Wherein x satisfies 0.05 <x <0.4, and a part of Sr may be substituted with at least one element selected from the group consisting of Mg, Ca, Ba and Zn)
_{(Sr 1-x-y,} Eu x, Dy y) Al 2 O 4 (4)
(Wherein x + y satisfies 0.05 <x + y <0.4, and a part of Sr may be substituted with at least one element selected from the group consisting of Mg, Ca, Ba and Zn)

  Among these, the alkaline earth metal aluminate is preferably at least one selected from the group consisting of formulas (1) and (3) from the viewpoint of light emission characteristics, and has a composition represented by formula (1). More preferably.

Phosphor particles The content of the alkaline earth metal aluminate contained in the phosphor particles is, for example, 80% by mass or more, preferably 90% by mass or more, and is substantially composed of alkaline earth metal aluminate. More preferred. The smaller the crystal structure other than the impurity phase and alkaline earth metal aluminate, the higher the crystallinity as a phosphor and the higher the light emission efficiency. The average particle diameter measured using the air permeation method of the phosphor particles is, for example, 5 μm or more, preferably 10 μm or more, and for example, 30 μm or less, preferably 25 μm or less. The volume median diameter measured using the pore electrical resistance method is, for example, 10 μm or more, preferably 15 μm or more, and for example, 35 μm or less, preferably 30 μm or less. When the average particle diameter and the volume median diameter are not less than the above lower limit value, the luminous efficiency of the phosphor particles tends to be improved. Further, when the average particle diameter and the volume median diameter are not more than the above upper limit values, the workability when producing a fluorescent member containing phosphor particles tends to be further improved.

  From the viewpoint of moisture resistance, the phosphor particles are preferably those in which elution of water from the surface of the constituent components is suppressed. For example, the elution amount of the phosphor particles with respect to pure water at 25 ° C. is, for example, 300 ppm or less, preferably 50 ppm or less, more preferably 40 ppm or less as the detected amount of alkaline earth metal.

  The detected amount of the eluted alkaline earth metal is measured as follows. Put 50 g of phosphor particles and 100 ml of pure water in a 65 mm diameter plastic container (capacity: 250 ml), place on a roll mixer, and rotate and stir for 2 hours at 85 rpm in an environment of 25 ° C. -Measured using AES (High Frequency Inductively Coupled Plasma Atomic Emission Spectroscopy).

  The phosphor particles in which the elution of the constituent components is suppressed can be prepared, for example, by washing and purifying the phosphor particles. Specifically, preparing phosphor particles containing an alkaline earth metal aluminate, contacting the prepared phosphor particles with a liquid medium containing water, and at least a part of the contacted liquid medium To obtain a purified phosphor particle, and a purification method comprising:

Phosphor particles containing alkaline earth metal aluminate are prepared by referring to the production method described in, for example, “Phosphor Handbook”, edited by Phosphors Association (Ohm), pages 227-228, etc. can do. Moreover, you may prepare by selecting the fluorescent substance which has a desired characteristic from what is marketed.
The prepared phosphor particles may be subjected to dispersion treatment, sieving treatment, classification treatment, and the like.

The liquid medium containing water with which the prepared phosphor particles are brought into contact may contain an acidic compound. Examples of acidic compounds include hydrochloric acid, nitric acid, sulfuric acid, acetic acid and the like. The pH of the liquid medium containing the acidic compound can be set to 1 to 5, for example.
The amount of the liquid medium brought into contact with the phosphor particles is, for example, 1 to 20 times on the mass basis, and preferably 5 to 15 times the phosphor particles.

  The contact between the phosphor particles and the liquid medium can be performed, for example, by immersing the phosphor particles in the liquid medium, and may be agitated as necessary. The temperature at the time of contact is, for example, 15 ° C. to 40 ° C., and the contact time can be, for example, 1 minute to 30 minutes.

The removal of the liquid medium can be performed, for example, by solid-liquid separation, and a drying process may be performed as necessary.
Contact and removal of the liquid medium with respect to the phosphor particles may be performed only once or a plurality of times.

Phosphoric acid compound A phosphoric acid compound is attached to the surface of the phosphor particles. Examples of phosphate compounds include Group 2 elements (alkaline earth metals) phosphates such as magnesium phosphate, calcium phosphate, strontium phosphate, and barium phosphate; scandium phosphate, yttrium phosphate, lanthanoids (La, Ce, Pr) , Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu) phosphates such as phosphates; boron phosphate, aluminum phosphate, gallium phosphate, phosphorus Group 13 element phosphates such as indium oxide; zinc phosphate, antimony phosphate, bismuth phosphate and the like can be mentioned, and at least one selected from the group consisting of these is preferable. More preferably, it is at least one selected from the group consisting of Group 2 element phosphates, rare earth phosphates and Group 13 element phosphates. More preferably, it is selected from the group consisting of magnesium phosphate, calcium phosphate, strontium phosphate, barium phosphate, aluminum phosphate, gallium phosphate, scandium phosphate, yttrium phosphate and lanthanide phosphate. It is at least one, and particularly preferably at least one selected from the group consisting of magnesium phosphate, calcium phosphate, strontium phosphate, barium phosphate, yttrium phosphate and lanthanum phosphate.

  As a method of attaching the phosphoric acid compound to the surface of the phosphor particles, a method of attaching a desired phosphoric acid compound to the surface of the phosphor by a dry or wet dispersion treatment, or generating a desired phosphoric acid compound in a liquid medium. Examples thereof include a method of adhering to the phosphor surface, a method of spraying a slurry containing a phosphoric acid compound on the phosphor particles by a dry method, and the like. Among these, from the viewpoint of moisture resistance, a method of generating a desired phosphoric acid compound in a liquid medium and attaching it to the phosphor surface is preferable.

  A method of generating a desired phosphate compound in a liquid medium and attaching it to the phosphor surface is, for example, contacting a cation forming a phosphate compound with a phosphate ion in a liquid medium containing phosphor particles. including. A desired phosphoric acid compound is produced by contacting the cation forming the phosphoric acid compound with the phosphoric acid ion, and the phosphoric acid compound can be adhered to the phosphor surface by being deposited on the phosphor surface. . Moreover, after making the cation and phosphate ion which form a phosphate compound contact in a liquid medium and producing | generating a desired phosphate compound, you may make it contact with fluorescent substance.

  For example, when the phosphate compound contains magnesium phosphate, calcium phosphate, strontium phosphate, barium phosphate, aluminum phosphate, gallium phosphate, scandium phosphate, yttrium phosphate or lanthanoid phosphate, calcium ion, magnesium ion, At least one cation selected from the group consisting of strontium ions, barium ions, aluminum ions, gallium ions, scandium ions, yttrium ions, and lanthanoid ions and phosphate ions are brought into contact with the surface of the phosphor particles. The phosphate compound can be attached. Also, for example, when the phosphate compound contains magnesium phosphate, calcium phosphate, strontium phosphate, barium phosphate, yttrium phosphate or lanthanoid phosphate, calcium ion, magnesium ion, strontium ion, barium ion, yttrium ion and lanthanoid ion The phosphoric acid compound can be attached to the surface of the phosphor particles by bringing a phosphate ion into contact with at least one cation selected from the group consisting of: In addition, a cation forming a phosphate compound and a phosphate ion may be brought into contact with each other in a liquid medium to form a desired phosphate compound, and then the phosphoric acid compound may be attached by being brought into contact with phosphor particles. .

  Contact between a cation forming a phosphate compound (hereinafter also referred to as “specific cation”) and a phosphate ion is performed by, for example, bringing a solution containing a phosphate ion and a desired cation into a liquid medium containing phosphor particles. It can carry out by adding the solution containing. Further, a solution containing a desired cation may be added to a liquid medium containing phosphor particles and phosphate ions.

  The liquid medium used for the contact between the specific cation and the phosphate ion includes, for example, water, and may include an organic solvent, a pH adjuster, and the like as necessary. Examples of the organic solvent that can be contained in the liquid medium include alcohols such as ethanol and isopropanol. Examples of the pH adjuster include basic compounds such as ammonia, sodium hydroxide, and potassium hydroxide, and acidic compounds such as hydrochloric acid, nitric acid, sulfuric acid, and acetic acid. When the liquid medium includes a pH adjuster, the pH of the liquid medium is, for example, 4 to 12, and preferably 6 to 9. In addition, pH of a liquid medium is a measured value in the state containing the cation and phosphate ion which form a phosphate compound.

  The mass ratio of the liquid medium to the phosphor particles is, for example, 100% by mass to 1000% by mass, and preferably 200% by mass to 800% by mass. When the mass ratio of the liquid medium is equal to or higher than the lower limit, the phosphoric acid compound can be more uniformly attached to the surface of the phosphor particles, and when the mass ratio of the liquid medium is equal to or lower than the upper limit, the phosphor of the phosphoric acid compound There exists a tendency for the adhesion rate to to improve more.

  The phosphate ion includes orthophosphate ion, polyphosphate (metaphosphate) ion, phosphite ion, and hypophosphite ion. Polyphosphate ions include polyphosphate ions having a linear structure such as pyrophosphate ions and tripolyphosphate ions, and cyclic polyphosphate ions such as hexametaphosphate.

  The solution containing phosphate ions is a solution in which a compound serving as a phosphate ion source is dissolved in a solvent such as water. Specific examples of the phosphate ion source include phosphoric acid; metaphosphoric acid; alkali metal phosphates such as sodium phosphate and potassium phosphate; alkali metal hydrogen phosphates such as sodium hydrogen phosphate and potassium hydrogen phosphate; phosphorus Alkali metal dihydrogen phosphates such as sodium dihydrogen phosphate and potassium dihydrogen phosphate; alkali metal hexametaphosphates such as sodium hexametaphosphate and potassium hexametaphosphate; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; Examples thereof include ammonium phosphate salts such as ammonium phosphate.

The concentration of the phosphate ion source in the liquid medium in which the specific cation and the phosphate ion are brought into contact is, for example, 0.1% by mass or more and 5.0% by mass or less as the content of phosphate ion (PO ₄ ³⁻ ). Yes, 0.2 mass% or more and 3.0 mass% or less are preferable. Moreover, the content rate of the phosphate ion source with respect to the quantity of the fluorescent substance particles in a liquid medium is 0.5 mass% or more and 20.0 mass% or less, for example, and 1.0 mass% or more and 10.0 mass% or less are preferable. When the concentration of the phosphate ion source is not less than the lower limit, the adhesion rate of the phosphate compound to the phosphor tends to be further improved, and when the concentration of the phosphate ion source is not more than the upper limit, It tends to be easier to adhere more uniformly to the phosphor particle surface.

  A solution containing a specific cation can be prepared by dissolving a compound (for example, a metal salt) serving as a cation source in a solvent such as water. Examples of the anion constituting the metal salt include nitrate ion, sulfate ion, acetate ion, chloride ion and the like.

  The content rate of the specific cation in the liquid medium in which the specific cation and the phosphate ion are brought into contact is, for example, 0.05% by mass or more and 4.0% by mass or less, and 0.1% by mass or more and 3.0% by mass. The following is preferred. Moreover, the content rate of the specific cation with respect to the amount of phosphor particles in the liquid medium is, for example, 0.1% by mass or more and 15% by mass or less, and preferably 0.2% by mass or more and 8.0% by mass or less. When the content rate of the specific cation is not less than the above lower limit value, the adhesion rate of the phosphoric acid compound to the phosphor tends to be further improved, and when the content rate of the specific cation is not more than the above upper limit value, phosphoric acid. It tends to be easier to adhere the compound more uniformly to the phosphor particle surface.

The contact temperature between the cation forming the phosphate compound and the phosphate ion is, for example, 10 ° C. to 50 ° C., and preferably 20 ° C. to 35 ° C. The contact time is, for example, 1 minute to 1 hour, and preferably 3 minutes to 30 minutes. The contact may be performed while stirring the liquid medium.
After making a phosphoric acid compound adhere to fluorescent substance particles, phosphoric acid compound adhesion fluorescent substance particles can be obtained by performing solid-liquid separation and drying processing, for example. The drying process may be performed at room temperature or may be performed by heating. When heating by a drying process, it can be 95 degreeC to 115 degreeC, for example.

  The phosphoric acid compound adheres to the surface of the phosphor particles regardless of whether it is a Van der Waals force, a physical interaction such as electrostatic interaction, or a chemical interaction due to a partial chemical reaction. Good. Further, the phosphoric acid compound may be attached in the form of particles or may be attached in a film form, and at least a part of the phosphate compound is preferably attached in a film form from the viewpoint of moisture resistance.

  The amount of the phosphoric acid compound attached to the phosphoric acid compound-attached phosphor particles is, for example, 0.0001% by mass or more and 20% by mass or less, preferably 0.1% by mass or more and 10% by mass or less as the phosphoric acid content. More preferably, the content is from 5% by mass to 5.6% by mass. There exists a tendency for sufficient moisture resistance to be acquired as the adhesion amount of a phosphoric acid compound is more than the said lower limit. Moreover, the fall of the light emission characteristic as fluorescent substance can be suppressed as it is below the said upper limit. Further, the content of the metal constituting the phosphoric acid compound is 0.0001% by mass or more and 20% by mass or less, preferably 0.01% by mass or more and 10% by mass or less, and 0.36% by mass or more and 1.4% by mass. The following is more preferable. Within this range, the crystal structure and composition of the phosphate compound tend to be more effective in achieving the object of the present invention.

Here, the phosphoric acid and phosphorous compound-containing metal content in the phosphoric acid compound-attached phosphor particles can be measured using ICP-AES (High Frequency Inductively Coupled Plasma Emission Spectroscopy). Phosphoric acid shows the value converted as phosphate ion (PO ₄ ³⁻ ). Moreover, the content rate of the phosphoric acid compound in phosphoric acid compound adhesion fluorescent substance particles is calculated | required as the sum of the content rate of a phosphoric acid, and the content rate of the metal which comprises a phosphoric acid compound.

Heat treatment The phosphor compound-attached phosphor particles obtained are heat-treated at a temperature of 500 ° C. or higher and 700 ° C. or lower, preferably 550 ° C. or higher and 650 ° C. or lower. By performing a heat treatment in a specific temperature range, a phosphor excellent in moisture resistance and luminous efficiency can be obtained. For example, it is considered that excellent moisture resistance can be achieved because adsorbed water, crystal water and the like are removed by heat treatment, and the crystallinity and chemical stability of the adhered phosphate compound are improved.

The heat treatment time is, for example, 1 hour to 20 hours, and preferably 3 hours to 15 hours.
The atmosphere at the time of heat treatment can be, for example, air or an inert gas atmosphere, or an atmosphere in which an inert gas is mixed with the air. Examples of the inert gas include rare gases such as nitrogen, helium, and argon. The heat treatment atmosphere is preferably a non-reducing atmosphere or a low reducing atmosphere. For example, the concentration of hydrogen gas is 3% by volume or less, and preferably 1% by volume or less.
The pressure during the heat treatment is, for example, 0.05 MPa to 0.2 MPa.

  The phosphor obtained by the heat treatment may be subjected to a crushing process, a dispersion process, a sieving process, a classification process, and the like as necessary.

  According to the manufacturing method, phosphor particles containing an alkaline earth metal aluminate and a phosphoric acid compound disposed on the surface of the phosphor particles, and in the differential scanning calorimetry, the endotherm at 25 ° C. to 650 ° C. Can be produced efficiently with a phosphor of 50 J / g or less. The obtained phosphor has excellent moisture resistance.

[Phosphor]
The phosphor according to the present embodiment has phosphor particles containing an alkaline earth metal aluminate and a phosphoric acid compound disposed on the surface of the phosphor particles, and in differential scanning calorimetry, from 25 ° C. The endothermic amount at 650 ° C. is 50 J / g or less.

  In the phosphor according to the present embodiment, the phosphoric acid compound disposed on the surface of the phosphor particles constituting the phosphor is disposed in a state where the endothermic amount in a specific temperature range is a specific value or less. It can show moisture resistance. The phosphor can be manufactured, for example, by the above-described phosphor manufacturing method.

The alkaline earth metal aluminate is excited by light of at least 220 nm to 470 nm and emits light having an emission peak wavelength in the range of 440 nm to 530 nm. Specifically, the alkaline earth metal aluminate is preferably a compound having a composition represented by any one selected from the group consisting of the aforementioned formulas (1) to (4), and emitting light From the viewpoint of characteristics, at least one having a composition represented by any formula selected from the group consisting of formulas (1) and (3) is preferable, and has a composition represented by the following formula (1) Is more preferable.
(Sr _1-x , Eu _x ) ₄ Al ₁₄ O ₂₅ (1)
In the formula (1), x satisfies 0.05 ≦ x ≦ 0.4, and a part of Sr is substituted with at least one element selected from the group consisting of Mg, Ca, Ba and Zn. Also good. From the viewpoint of luminous efficiency, x preferably satisfies 0.1 ≦ x ≦ 0.3. When a part of Sr is substituted with at least one element selected from the group consisting of Mg, Ca, Ba and Zn, the substitution amount is, for example, 50 mol% or less, and 1 mol% or more and 30 mol% The following is preferred.

  The phosphoric acid compound is disposed on the surface of the phosphor particles. The details of the phosphoric acid compound are as described above, and the preferred embodiments are also the same. The arrangement of the phosphoric acid compound may be any of physical interaction such as van der Waals force and electrostatic interaction, chemical interaction due to partial chemical reaction, and the like. Moreover, the phosphoric acid compound may be arrange | positioned in the particle | grain state, may be arrange | positioned at the film form, and in order to improve moisture resistance more, it is preferable to arrange | position at the film form. Here, the phosphoric acid compound is arranged in the form of a film means that phosphoric acid compound particles are not observed, and the surface of the phosphor particles accounts for 50% or more, preferably 70% or more of the area of the phosphor particles. Say that it is covered.

  The phosphoric acid compound content in the phosphor is, for example, 0.0001 mass% or more and 20 mass% or less, and 0.1 mass% or more and 10 mass% or less as the phosphoric acid content in the total mass of the phosphor. It is preferably 1% by mass or more and 8% by mass or less, and more preferably 1.5% by mass or more and 5.6% by mass or less. When the content of the phosphoric acid compound is not less than the above lower limit value, sufficient moisture resistance tends to be obtained, and when it is not more than the above upper limit value, it is possible to suppress a decrease in luminous efficiency as a phosphor. The content of the metal constituting the phosphoric acid compound is 0.0001% by mass to 20% by mass, preferably 0.01% by mass to 10% by mass, and more preferably 0.2% by mass to 3% by mass. More preferably, it is 0.36 mass% or more and 1.4 mass% or less. Within this range, the crystal structure and composition of the phosphate compound tend to be more effective in achieving the object of the present invention.

Here, the content rate of the metal which comprises phosphoric acid and a phosphoric acid compound in a fluorescent substance can each be measured using ICP-AES (high frequency inductively coupled plasma emission spectroscopy). Phosphoric acid showed values converted as PO _4. Moreover, the content rate of the phosphoric acid compound in phosphoric acid compound adhesion fluorescent substance particles is calculated | required as the sum of the content rate of a phosphoric acid, and the content rate of the metal which comprises a phosphoric acid compound.

  In the differential scanning calorimetry (DSC), the phosphor has an endotherm at 25 ° C. to 650 ° C. of 50 J / g or less, preferably 20 J / g or less, more preferably 15 J / g or less, and substantially 0 J / g. More preferably. For example, when phosphoric acid compound-attached phosphor particles in the above-described phosphor manufacturing method are heat-treated at a specific temperature, the adhering phosphate compound absorbs heat and changes physically or chemically. It is thought that excellent moisture resistance can be imparted to the body. Therefore, it is considered that the endothermic amount of the phosphor after the heat treatment is not more than a predetermined value means that the physical or chemical change of the attached phosphate compound has sufficiently progressed.

  The phosphor preferably has a phosphoric acid compound content of 1.5% by mass or more and 5% by mass or less, and an endothermic amount of DSC at 25 ° C. to 650 ° C. of 20 J / g or less. More preferably, the content is 1.86% by mass or more and 3.24% by mass or less, and the endothermic amount of DSC at 25 ° C. to 650 ° C. is 20 J / g or less, and the content of the phosphoric acid compound is 5. More preferably, the heat absorption amount at 25 ° C. to 650 ° C. of DSC is 50 J / g or less.

  The endothermic amount is calculated as a value corresponding to the area surrounded by a straight line connecting both shoulders of the endothermic peak and the DSC curve with respect to the endothermic peak in the DSC curve with the temperature on the horizontal axis and the amount of heat on the vertical axis. When a plurality of endothermic peaks exist in a predetermined temperature range, the value corresponds to the sum of the areas of the respective endothermic peaks. When no endothermic peak is observed in the DSC curve, the endothermic amount is substantially 0 J / g.

  From the viewpoint of luminous efficiency, the phosphor is preferably obtained by heat treating phosphor compound-attached phosphor particles at a specific temperature or lower. The phosphor is heat-treated at a specific temperature or lower. For example, when the maximum peak intensity in the excitation spectrum is 100%, the relative intensity at 270 nm can be 60% or more, preferably 70% or more. can do.

  The average particle diameter measured using the air permeation method of the phosphor after the heat treatment is, for example, 5 μm or more, preferably 10 μm or more, and for example, 30 μm or less, preferably 25 μm or less. The volume median diameter measured using the pore electrical resistance method is, for example, 10 μm or more, preferably 15 μm or more, and for example, 35 μm or less, preferably 30 μm or less.

[Light emitting device]
A light-emitting device includes the phosphor (hereinafter also referred to as “first phosphor”) and a light-emitting element having an emission peak wavelength in a wavelength range of 380 nm to 470 nm, and the emission of the phosphor in an emission spectrum. The ratio of the emission intensity at the emission peak wavelength of the light emitting device to the emission intensity at the peak wavelength is 10 or less. By combining the phosphor and the light emitting element, a light emitting device having excellent moisture resistance can be configured. The light emitting device can further include another phosphor (hereinafter, also referred to as “second phosphor”) in combination.

  Examples of the light emitting device include a pin penetration type and a surface mounting type. In general, the pin through type refers to a type in which a light emitting device is fixed by penetrating leads (pins) of the light emitting device through through holes provided in a mounting substrate. The surface mount type refers to a type in which the lead of the light emitting device is fixed on the surface of the mounting substrate.

A light emitting device 100 according to an embodiment of the present invention will be described with reference to the drawings. 1 and 2 are schematic cross-sectional views showing the light emitting device 100. FIG. The light emitting device 100 is an example of a surface mount type light emitting device.
The light emitting device 100 emits light on the short wavelength side of visible light (for example, a range of 380 nm to 485 nm), and the light emitting device 10 of a gallium nitride compound semiconductor having an emission peak wavelength in a range of 430 nm to 470 nm, And a molded body 40 on which the light emitting element 10 is placed. The molded body 40 is formed by integrally molding the first lead 20 and the second lead 30 and a resin portion 42 containing a thermoplastic resin or a thermosetting resin. The molded body 40 has a recess having a bottom surface and side surfaces, and the light emitting element 10 is placed on the bottom surface of the recess. The light emitting element 10 has a pair of positive and negative electrodes, and the pair of positive and negative electrodes are electrically connected to the first lead 20 and the second lead 30 through wires 60, respectively. The light emitting element 10 is covered with a fluorescent member 50. The fluorescent member 50 includes, for example, a phosphor 70 that converts the wavelength of light from the light emitting element 10 and a resin in FIG. 1, and a first phosphor 71 and a second phosphor 72 as the phosphor 70 in FIG. 2. Resin.

The fluorescent member 50 not only converts the wavelength of light emitted from the light emitting element 10, but also functions as a member for protecting the light emitting element 10 from the external environment. In FIGS. 1 and 2, the phosphor 70 is unevenly distributed in the fluorescent member 50. Thus, by arranging the phosphor 70 close to the light emitting element 10, the wavelength of light from the light emitting element 10 can be efficiently converted, and a light emitting device having excellent light emission efficiency can be obtained. The arrangement of the fluorescent member 50 including the phosphor 70 and the light emitting element 10 is not limited to the form in which they are arranged close to each other, and the fluorescent member is considered in consideration of the influence of heat on the phosphor 70. 50, the light emitting element 10 and the phosphor 70 may be spaced apart. In addition, by mixing the phosphor 70 with the entire fluorescent member 50 at a substantially uniform ratio, it is possible to obtain light in which color unevenness is further suppressed.
In FIG. 2, the phosphor 70 is configured by mixing a first phosphor 71 and a second phosphor 72, but the second phosphor 72 is disposed on the first phosphor 71 (not shown). Or the first phosphor 71 may be disposed on the second phosphor 72 (not shown).

Light-Emitting Element The emission peak wavelength of the light-emitting element is in the range of 430 nm to 470 nm, and is preferably in the range of 440 nm to 460 nm, preferably in the range of 445 nm to 455 nm, from the viewpoint of the light emission efficiency of the light-emitting device. More preferred. A light-emitting device that uses such a light-emitting element as an excitation light source and emits mixed-color light of light from the light-emitting element and fluorescence from a phosphor is configured.

The half width of the emission spectrum of the light emitting element can be set to 30 nm or less, for example.
It is preferable to use a semiconductor light emitting element such as an LED as the light emitting element. By using a semiconductor light emitting element as a light source, it is possible to obtain a stable light emitting device with high efficiency, high output linearity with respect to input, and strong against mechanical shock.
As a semiconductor light emitting element, for example, a blue color using a nitride semiconductor (In _X Al _Y Ga _1- XYN, where X and Y satisfy 0 ≦ X, 0 ≦ Y, and X + Y ≦ 1). A semiconductor light emitting element that emits light can be used.

The first phosphor The light emitting device includes at least one of the first phosphors including phosphor particles on the surface of which phosphoric acid compounds are arranged and containing alkaline earth aluminate.
The details of the first phosphor are as described above, and the preferred embodiments are also the same.

  A 1st fluorescent substance can be contained in a fluorescent member with resin, and can comprise a light-emitting device. The content of the first phosphor is, for example, 2% by mass or more, preferably 10% by mass or more, more preferably 40% by mass or more, and for example, 190% by mass or less, with respect to the resin amount of the fluorescent member. 160 mass% or less is preferable and 130 mass% or less is more preferable.

  In the light emitting device, the ratio of the emission intensity at the emission peak wavelength of the light emitting element to the emission intensity at the emission peak wavelength of the first phosphor (hereinafter also referred to as “emission intensity ratio”) is 10 or less, preferably 1 or less. . The emission intensity ratio is, for example, 0.2 or more, preferably 0.4 or more. Here, the emission peak wavelength of the first phosphor is a wavelength that gives the maximum value of the relative intensity in the wavelength range of 485 nm to 500 nm in the emission spectrum of the light emitting device. The light emission intensity ratio can be controlled by adjusting the content of the first phosphor in the light emitting device.

  The light emission spectrum of the light emitting device having a light emission intensity ratio of 10 or less is, for example, close to the spectrum of sunlight after passing through seawater at a certain depth. Thus, for example, by applying the light emitting device to a fish collection lamp, it is expected that excellent moisture resistance and fish collection effect can be achieved.

Second phosphor In addition to the first phosphor, the light-emitting device of the present embodiment may further include a second phosphor having a light emission peak wavelength different from that of the first phosphor. By having the second phosphor, a light emitting device capable of emitting light of various hues can be configured.

  Examples of the second phosphor include a phosphor having an emission peak wavelength in a wavelength range of 450 nm to 700 nm.

Specific examples of the second phosphor include phosphors having a composition represented by any of the following formulas (I) to (X). As the second phosphor, at least one selected from these phosphors can be used.
_{(Ca 1-p-q Sr} p Eu q) AlSiN 3 (I)
In formula (I), p and q satisfy 0 ≦ p ≦ 1.0, 0 <q <1.0 and p + q <1.0.

_{(Ca 1-r-s-} t Sr r Ba s Eu t) 2 Si 5 N 8 (II)
In the formula (II), r, s, and t satisfy 0 ≦ r ≦ 1.0, 0 ≦ s ≦ 1.0, 0 <t <1.0, and r + s + t ≦ 1.0.

A ₂ [M ¹ _1-u Mn ⁴⁺ _u F ₆ ] (III)
In Formula (III), A is at least one selected from the group consisting of K, Li, Na, Rb, Cs and NH ₄ , and M ¹ is a group consisting of Group 4 elements and Group 14 elements. And u satisfies 0 <u <0.2.

(I-j) MgO. (J / 2) Sc ₂ O ₃ .kMgF ₂ .mCaF _2. (1-n) GeO _2. (N / 2) M ^t ₂ O ₃ : zMn ⁴⁺ (IV)
In the formula (IV), M ^t is at least one selected from the group consisting of Al, Ga and In, and i, j, k, m, n and z are 2 ≦ i ≦ 4 and 0 <k, respectively. <1.5, 0 <z <0.05, 0 ≦ j <0.5, 0 <n <0.5, and 0 ≦ m <1.5.

M ¹¹ ₈ MgSi ₄ O ₁₆ X ¹¹ ₂ : Eu (V)
In formula (V), M ¹¹ is at least one selected from the group consisting of Ca, Sr, Ba and Zn, and X ¹¹ is at least one selected from the group consisting of F, Cl, Br and I. is there.

_{Si 6-z Al z O z} N 8-z: Eu (VI)
In the formula (VI), z satisfies 0 <z <4.2.

_{M m / n Si 12- (m} + n) Al (m + n) O n N (16-n): Eu (VII)
In formula (VII), M is at least one selected from the group consisting of Sr, Ca, Li and Y. n is 0 to 2.5, m is 0.5 to 5, n is the charge of M, and x is 0.75 to 1.5.

M ¹³ Ga ₂ S ₄ : Eu (VIII)
In the formula (VIII), M ¹³ is at least one selected from the group consisting of Mg, Ca, Sr and Ba.

(Y, Lu, Gd, Tb) ₃ (Al, Ga) ₅ O ₁₂ : Ce (IX)

_{^{M a v M b w M c}} x Al 3-y Si y N z (X)
In formula (X), M ^a is at least one element selected from the group consisting of Ca, Sr, Ba and Mg, and M ^b is at least one selected from the group consisting of Li, Na and K. And M ^c is at least one element selected from the group consisting of Eu, Ce, Tb and Mn, and v, w, x, y and z are each 0.80 ≦ v ≦ 1.05, 0.80 ≦ w ≦ 1.05, 0.001 <x ≦ 0.1, 0 ≦ y ≦ 0.5, 3.0 ≦ z ≦ 5.0 are satisfied.

  When the light emitting device includes a fluorescent member including a second phosphor and a resin in addition to the first phosphor, the content of the second phosphor is, for example, 1% by mass or more with respect to the amount of the resin, and 5% by mass. The above is preferable, 10 mass% or more is more preferable, and it is 200 mass% or less, for example, 150 mass% or less is preferable, and 100 mass% or less is more preferable.

Fluorescent Member The light emitting device includes, for example, a fluorescent member that includes a phosphor and a resin and covers the light emitting element. Examples of the resin constituting the fluorescent member include thermoplastic resins and thermosetting resins. Specific examples of the thermosetting resin include modified silicone resins such as epoxy resins, silicone resins, and epoxy-modified silicone resins.
The fluorescent member may contain other components as needed in addition to the phosphor and the resin. Examples of other components include fillers such as silica, barium titanate, titanium oxide, and aluminum oxide, light stabilizers, and colorants. When the fluorescent member contains other components, the content thereof can be appropriately selected according to the purpose and the like. For example, when a filler is included as another component, the content thereof can be 0.01% by mass to 20% by mass with respect to the resin.

  Examples according to the present invention will be specifically described below.

(Production example)
Method for producing phosphor particles (Method for producing alkaline earth metal aluminate phosphor)
For the alkaline earth metal aluminate phosphor having the composition represented by the formula (1), refer to the production method described in “Phosphor Handbook”, edited by Phosphors Association (Ohm), pages 227 to 228, etc. And manufactured. Specifically, after various raw materials were weighed in the blending amounts shown in Table 1, dry mixing was performed, and firing was performed at 1350 ° C. for 10 hours in a reducing atmosphere. Further, after the dispersion treatment, coarse particles and fine particles were removed with a wet sieve or the like, and alkaline earth metal aluminate phosphors A to F having powder characteristics shown in Table 2 were prepared.

In Table 2, the average particle diameter is the Fischer sub-sieve sizer number, and was measured with Fischer sub-sieve sizer (manufactured by Fischer) using the air permeation method. Dm is a volume median diameter, and was measured with a Coulter Multisizer II (manufactured by Beckman Coulter, Inc.) using a pore electrical resistance method.
As emission characteristics, chromaticity coordinates x and y of fluorescence by excitation light of 450 nm and an ENG value indicating emission intensity are shown. The ENG value is shown as a relative value based on the phosphor 1 obtained in Example 1 described later. The relative intensity (%) at 270 nm when the maximum intensity in each excitation spectrum was 100% was shown as the excitation spectrum relative intensity (%).
Here, the phosphor A corresponds to a phosphor in which x in the formula (1) is 0.1 / 4 = 0.025, and the phosphor B is a phosphor in which x is 0.2 / 4 = 0.05. And the value of x is similarly calculated for phosphors C to F.

Example 1
Using phosphor B synthesized by the above method as phosphor particles, 300 g of pure water was added to 150 g of phosphor and stirred to obtain a dispersion. To the dispersion, 245.1 g of a sodium salt solution of phosphoric acid (phosphate ion content 2.25% by mass) was dropped. Next, 174.5 g of a calcium nitrate solution (Ca content 2.0 mass%) was dropped. Furthermore, pH was adjusted to 7.5 using NaOH solution, and the reaction liquid was obtained. The reaction solution was stirred at room temperature (25 ° C.) for 1 hour, filtered, solid-liquid separated and then dried to obtain phosphoric acid compound-attached phosphor particles.
When the obtained phosphor compound-attached phosphor particles were analyzed by ICP-AES (High Frequency Inductively Coupled Plasma Emission Spectroscopy), the phosphate analysis value in terms of phosphate ion (PO ₄ ³⁻ ) was 2.6% by mass. A phosphoric acid compound having a Ca analysis value of 0.62% by mass was detected.
Further, a heat treatment was performed in the atmosphere at 600 ° C. for 10 hours to obtain phosphor 1.
Table 3 shows the powder characteristics and analytical values of the obtained phosphor 1.

(Examples 2 to 6)
Phosphors 2 to 6 were obtained in the same manner as in Example 1 except that phosphors C to F and A were used instead of phosphor B as phosphor particles. Table 3 shows the powder characteristics and analytical values of the obtained phosphor.

(Example 7)
Using phosphor D as the phosphor particles, changing the dropping amount of sodium phosphate solution (phosphate ion content 2.25 mass%) to 122.4 g, and calcium nitrate solution (Ca content 2) Phosphor mass 7 was obtained in the same manner as in Example 1 except that the dripping amount of 0.0 mass% was changed to 87.2 g. Table 3 shows the powder characteristics and analysis values of the obtained phosphor 7.

(Example 8)
Use of phosphor D as phosphor particles, change of dropping amount of sodium phosphate solution (phosphate ion content 2.25% by mass) to 367.6 g, and calcium nitrate solution (Ca content 2) Phosphor mass 8 was obtained in the same manner as in Example 1, except that the dripping amount of 0.0 mass% was changed to 261.8 g. Table 3 shows the powder characteristics and analysis values of the obtained phosphor 8.

Example 9
The phosphor D was used as the phosphor particles, the dropping amount of the sodium phosphate solution (phosphate ion content 2.25% by mass) was changed to 489.8 g, and the calcium nitrate solution (Ca content 2). 0.0 mass%) except that the amount of dripping was changed to 348.8 g, phosphorous compound-attached phosphor particles 9p were obtained in the same manner as in Example 1 and then heat treated in the same manner to obtain phosphor 9. It was. Table 3 shows the powder characteristics and analytical values of the phosphor 9 obtained.

(Example 10)
A phosphor 10 was obtained in the same manner as in Example 3 except that the heat treatment atmosphere was changed to a nitrogen atmosphere. Table 3 shows the powder characteristics and analysis values of the obtained phosphor 10.

(Example 11)
After 150 g of phosphor D was put in 1500 ml of an acidic solution (0.2% by mass hydrochloric acid) and washed, it was separated into solid and liquid, and further washed with water and dried to obtain purified phosphor D1.
A phosphor 11 was obtained in the same manner as in Example 10 except that the phosphor D1 was used. Table 3 shows the powder characteristics and analysis values of the obtained phosphor 11.

  50 g of phosphor D1 and 100 ml of pure water were placed in a 250 ml φ65 mm plastic container and rotated at 85 rpm for 2 hours, and then the Sr concentration in the supernatant was analyzed. As a result, the Sr analysis value was 35 ppm. On the other hand, the Sr analysis value of phosphor D analyzed in the same manner was 250 ppm.

(Example 12)
150 g of phosphor D was put in 1500 ml of an acidic solution (0.2% by mass hydrochloric acid) and washed, followed by solid-liquid separation, and further washing with water and solid-liquid separation to obtain purified phosphor D2. The Sr analysis value of the obtained phosphor D2 was the same as that of the phosphor D1.
Except having used fluorescent substance D2, it carried out similarly to Example 10, and after making a phosphoric acid compound adhere, it heat-processed and obtained fluorescent substance 12. Table 3 shows the powder characteristics and analytical values of the phosphor 12 obtained.

(Example 13)
Except that the phosphor D2 obtained in Example 12 was used, in the same manner as in Example 3, a phosphoric acid compound was attached and then heat treated to obtain phosphor 13. Table 3 shows the powder characteristics and analytical values of the phosphor 13 obtained.

(Comparative Example 1)
A phosphor C1 was obtained in the same manner as in Example 1 except that the phosphor D was used as the phosphor particles and no heat treatment was performed. Table 4 shows the powder characteristics and analysis values of the obtained phosphor C1.

(Comparative Example 2)
A phosphor C2 was obtained in the same manner as in Example 1 except that the phosphor D was used as the phosphor particles and the temperature of the heat treatment was 400 ° C. Table 4 shows the powder characteristics and analysis values of the obtained phosphor C2.

(Comparative Example 3)
A phosphor C3 was obtained in the same manner as in Example 1 except that the phosphor D was used as the phosphor particles and the temperature of the heat treatment was 800 ° C. Table 4 shows the powder characteristics and analysis values of the obtained phosphor C3.

Differential scanning calorimetry (DSC) of phosphors
Differential scanning calorimetry was performed on the phosphor 9 after heat treatment obtained in Example 9 and the phosphor compound-attached phosphor particles 9p before heat treatment under the following measurement conditions. The measurement results are shown in FIGS. FIG. 9 shows a DSC curve of the phosphor compound-attached phosphor particles 9p, and FIG. 10 shows a DSC curve of the phosphor 9.

(DSC condition)
Equipment: EXSTAR6000 (manufactured by Hitachi High-Tech Science Co., Ltd.)
Sample amount: 18.5mg
Measurement temperature range: 25 ° C to 650 ° C
Temperature increase rate: 10 ° C / min
Atmosphere: Air Flow rate: 50 ml / min

From the DSC curves of FIGS. 9 and 10, it can be seen that two endothermic peaks are observed in the phosphor compound-attached phosphor particles 9p before the heat treatment, and no clear endothermic peak is observed in the phosphor 9 after the heat treatment. From the obtained DSC curve, the endothermic amount at 25 ° C. to 650 ° C. was calculated, and it was 0 J / g for the phosphor 9 and 112 J / g for the phosphor compound-attached phosphor particles 9p.
Regarding the phosphors of Examples 1 to 8 and 10 to 13, the endothermic amount at 25 ° C. to 650 ° C. is the same as that of the phosphor 9.

Production of light-emitting device (Example L1)
The phosphor 1 obtained in Example 1 was added at a content rate relative to the silicone resin shown in Table 5 so that the chromaticity coordinates of the light emitted from the light-emitting device were in the vicinity of x = 0.150 and y = 0.175. Then, after mixing and dispersing, further defoaming was performed to obtain a phosphor-containing resin composition. Next, this phosphor-containing resin composition was injected and filled onto a light emitting device of an LED package (emission peak wavelength of light emitting device 450 nm), and further heated at 150 ° C. for 4 hours to cure the resin composition. The light emitting device 1 was manufactured through such steps. The phosphor content is a percentage based on mass when the silicone resin is 100 mass%.

The obtained light emitting device 1 was measured for light emission characteristics. Moreover, the obtained light-emitting device 1 was installed in a thermostat set to a temperature of 60 ° C. and a humidity of 90%, and the light-emitting device 1 was lit at a current value of 150 mA to perform a reliability test of the light-emitting device 1. The reliability of the light-emitting device 1 was evaluated by measuring the color tone before and after lighting in a thermostatic chamber. Specifically, the color tone was evaluated by the shift amount (defined by Δy below) of the color tone after 1000 hours of lighting in the thermostatic chamber with respect to the color tone before lighting in the thermostatic bath. The shift amount of the color tone was evaluated by the y value of the chromaticity coordinates. The above evaluation results are shown in Table 5.
Δy = (y value after 1000 hours) − (y value before lighting)

(Examples L2 to L11)
As the phosphor, instead of phosphor 1, phosphors 2 to 11 as shown in Table 5 were used, respectively, except that phosphors 2 to 11 were used, and light emitting devices 2 to 11 were produced. evaluated. The evaluation results are shown in Table 5.

(Comparative Examples L1 to L5)
A light-emitting device was fabricated in the same manner as in Example L1 except that phosphors C1, C2 and phosphors D to F were used as phosphors instead of phosphor 1, respectively, as shown in Table 6. And evaluated. The evaluation results are shown in Table 6 together with the results of Example L3.

(Examples 21 to 29)
The phosphor 3 obtained in Example 3 was added at a content rate relative to the silicone resin shown in Table 7. Further, 0.4% by mass of silica filler was added to the resin, mixed and dispersed, and then defoamed. Thus, a phosphor-containing resin composition was obtained. Next, this phosphor-containing resin composition was injected and filled onto a light emitting device of an LED package (emission peak wavelength of light emitting device 450 nm), and further heated at 150 ° C. for 4 hours to cure the resin composition. The light emitting devices 21 to 29 were produced by such processes.

  The light emitting characteristics of the obtained light emitting device were measured. Further, the light emission intensity at the emission peak wavelength of the light emitting element is “light emission element emission intensity A”, and the emission intensity at the emission peak wavelength of the phosphor is “phosphor emission intensity B”. A ratio (A / B) was calculated. The results are shown in Table 7. Further, emission spectra of the light emitting devices 21 to 29 are shown in FIG.

Regarding the amount of Eu and the powder characteristics in the phosphor composition For phosphors A to F and phosphors 1 to 6, from Tables 2, 3 and 4, the value of x in the formula (1) is 0.05 ≦ x ≦ 0. It can be seen that the luminous efficiency is particularly high in the range of .4.

About LED reliability As for the LED reliability with respect to the wet heat of Comparative Examples L3 to L5 in Table 6, Δy increases as the amount of Eu increases, and it can be seen that the deterioration of the phosphor is larger. It can be seen that the LED reliability with respect to the wet heat of Examples L1 to L6 in Tables 5 and 6 is small in Δy and the deterioration of the phosphor is small.

  As described above, in the phosphor of the prior art, the Eu amount in the phosphor composition is 0.2 to 1.6, that is, the luminous efficiency is high when x in the formula (1) is 0.05 ≦ x ≦ 0.4, The reliability was low and it was difficult to achieve both efficiency and reliability. However, by performing the phosphoric acid compound treatment and heat treatment according to the present embodiment, the LED has high LED reliability even when the light emission efficiency is high, 0.05 ≦ x ≦ 0.4, and high light emission efficiency and LED reliability. It is possible to achieve both.

Heat Treatment Temperature FIG. 3 shows an SEM image of phosphor D, FIG. 4 shows an SEM image of phosphor C1 that has not been heat treated, FIG. 5 shows an SEM image of phosphor C2 heat treated at 400 ° C., and heat treatment at 600 ° C. The SEM images of the phosphor 3 thus obtained are shown in FIG.
From the SEM image, it can be seen that after the phosphate compound adhesion treatment, the phosphate compound is adhered to the surface of the phosphor particles in the form of fine particles or a film. After the heat treatment at 400 ° C., at least a part of the phosphoric acid compound adheres in the form of fine particles, but after the heat treatment at 600 ° C., the phosphoric acid compound melts and adheres to the surface of the phosphor particles in the form of a film. I understand that.
The light emitting device using the phosphors C1 and C2 has a larger Δy shift than the light emitting device using the phosphor 3, and the LED reliability is low. Therefore, the LED reliability is obtained by heat treatment at a temperature of 500 ° C. or higher. It turns out that the improvement effect of becomes larger.

  FIG. 7 shows excitation spectra of phosphor C1 that has not been heat-treated, phosphor C2 that has been heat-treated at 400 ° C., phosphor C3 that has been heat-treated at 800 ° C., and phosphor 3 that has been heat-treated at 600 ° C. In the phosphor C3 heat-treated at 800 ° C., the relative intensity at 270 nm is 40% when the peak intensity of the excitation spectrum is 100%, and it can be seen that the relative intensity is reduced. This is probably because the phosphor was deteriorated because the heat treatment temperature was too high.

About the adhesion amount of a phosphoric acid compound From Example 3, 7, 8, and 9 in Table 3, the shift of (DELTA) y is small in the range whose sum of a phosphoric acid analysis value and Ca analysis value is 3.24-7.0, LED. It can be confirmed that the reliability improvement effect is higher.

About the atmosphere at the time of heat processing From Examples 3 and 10, it can be confirmed that the light emission efficiency and the LED reliability were improved by the heat treatment in the air and nitrogen atmosphere.

Regarding purification treatment of phosphor particles From Examples 10 and 11, it is confirmed that the phosphor particles are treated with an acidic solution and the phosphor compound treatment and heat treatment are performed on a phosphor having a small Sr analysis value, thereby achieving higher efficiency. it can. The Sr analysis values are 250 ppm in Example 10, 35 ppm in Example 11, and 14 ppm in Example 12. By reducing the amount of phosphor components eluted from the surface of the phosphor particles, the amount of phosphor components eluted from the phosphor particles during the phosphate compound deposition treatment is reduced, and the phosphate compound deposition treatment can be performed more effectively. it is conceivable that.
Moreover, from Examples 12 and 13, it can be seen that the cleaning treatment is sufficient for the purification treatment of the phosphor particles, and the drying treatment is not essential.

  FIG. 11 shows spectra for various light sources, the wavelength on the horizontal axis and the light intensity on the vertical axis. FIG. 11 shows sunlight, a 1 W output metal halide lamp, a 1 W output white light emitting device (correlated color temperature 5000K), a 1 W output semiconductor light emitting element having an emission peak at 490 nm, and a 1 W output light emitting device according to the present disclosure. A spectrum with 光源 as a light source is shown. From the spectrum, sunlight shows the same light intensity over a wide wavelength range, and the metal halide lamp (1W) used as a fish collection lamp has a light emission peak near 590 nm, but the light intensity is also comparable over a wide range. It can be seen that On the other hand, it can be seen that the white light emitting device, the semiconductor light emitting element, and the light emitting device according to the present embodiment each show a spectrum having an emission peak at a specific wavelength.

  FIG. 12 shows spectra of various light sources observed after passing through seawater having a depth of 50 m. It can be seen that sunlight shows a relatively wide spectrum with a strong light intensity having a peak near 490 nm. It can be seen that the light intensity decreases in the metal halide lamp and the white light emitting device. Moreover, although a semiconductor light-emitting device shows high light intensity, it turns out that a spectrum half value width becomes about half compared with sunlight. On the other hand, it turns out that the light-emitting device which concerns on this embodiment shows a spectrum equivalent to sunlight. Since the visibility curve of marine organisms (for example, squid) is a spectrum having a peak at around 490 nm and a relatively wide half-value width, by applying the light emitting device according to this embodiment to a fish collection lamp, for example, It can be seen that an excellent fish collection effect can be expected with excellent energy efficiency as compared with the case of using a metal halide lamp or a semiconductor light emitting element.

  The phosphor according to the present embodiment, the manufacturing method thereof, and the light-emitting device are used in a wide range of fields such as general lighting, in-vehicle lighting, display, fishlight, ornamental lighting, warning light, security light, display light, and liquid crystal backlight. Can be used.

  10: Light emitting element, 50: Fluorescent member, 70: Phosphor, 71: First phosphor, 72: Second phosphor, 100: Light emitting device

Claims (11)

Preparing phosphor particles containing an alkaline earth metal aluminate having a composition represented by the following formula (1):
Bringing the prepared phosphor particles into contact with a liquid medium containing water;
Removing at least a portion of the contacted liquid medium to obtain purified phosphor particles;
Attaching a phosphoric acid compound to the surface of the purified phosphor particles to obtain phosphoric acid compound-attached phosphor particles;
Heat-treating the phosphor compound-attached phosphor particles at 500 ° C. or more and 700 ° C. or less;
The manufacturing method of the fluorescent substance containing this.
(Sr _1-x , Eu _x ) ₄ Al ₁₄ O ₂₅ (1)
(In the formula (1), x satisfies 0.05 ≦ x ≦ 0.4, and a part of Sr is substituted with at least one element selected from the group consisting of Mg, Ca, Ba and Zn. May be.)   The production method according to claim 1, wherein the liquid medium containing water contains an acidic compound.   The production method according to claim 1 or 2, wherein an amount of the purified phosphor particles eluted with respect to pure water at 25 ° C is 50 ppm or less as a detected amount of alkaline earth metal.   The phosphate compound is at least one phosphate selected from the group consisting of magnesium phosphate, calcium phosphate, strontium phosphate, barium phosphate, yttrium phosphate and lanthanoid phosphates. The manufacturing method of any one of Claims.   In a liquid medium containing the phosphor particles, phosphate ions are brought into contact with at least one cation selected from the group consisting of calcium ions, magnesium ions, strontium ions, barium ions, yttrium ions, and lanthanoid ions. The manufacturing method according to any one of claims 1 to 4, wherein the phosphoric acid compound is attached to a surface of the phosphor particles. Phosphor particles containing alkaline earth metal aluminate, and phosphoric acid compound disposed on the surface of the phosphor particles,
A phosphor having an endotherm at 25 ° C. to 650 ° C. of 50 J / g or less in differential scanning calorimetry. The phosphor according to claim 6, wherein the alkaline earth metal aluminate has a composition represented by the following formula (1).
(Sr _1-x , Eu _x ) ₄ Al ₁₄ O ₂₅ (1)
(In the formula (1), x satisfies 0.05 ≦ x ≦ 0.4, and a part of Sr is substituted with at least one element selected from the group consisting of Mg, Ca, Ba and Zn. May be.)   The phosphor according to claim 7, wherein x satisfies 0.1 ≦ x ≦ 0.3.   The phosphor according to any one of claims 6 to 8, wherein the relative intensity at 270 nm is 60% or more when the maximum peak intensity in the excitation spectrum is 100%. An emission intensity at an emission peak wavelength of the phosphor in an emission spectrum, comprising: the phosphor according to any one of claims 6 to 9; and a light emitting element having an emission peak wavelength in a wavelength range of 380 nm to 470 nm. A light emitting device having a ratio of light emission intensity at a light emission peak wavelength of the light emitting element to 10 or less.   The light-emitting device according to claim 10, wherein the ratio is 1 or less.