JP2017186524A - Fluophor, light-emitting device and manufacturing method of fluophor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method of a fluophor of red luminescence excellent in durability.SOLUTION: There is provided a manufacturing method of a fluophor including preparing a fluophor particle containing a fluoride having Mn, at least one kind selected from a group consisting of alkali metal element and NHand at least one kind selected from a group consisting of Group 4 element and Group 14 element, obtaining a rare earth phosphate-adhered fluophor particle where rare earth phosphate adheres to the fluophor particle by contacting at least one kind of cation selected from rare earth element and phosphoric acid ion in a liquid medium containing the fluophor particle, and separating the rare earth phosphate-adhered fluophor particle and the liquid medium.SELECTED DRAWING: Figure 1B

Description

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

  A light emitting diode (LED) is a semiconductor light emitting element (hereinafter also referred to as “light emitting element”) produced from a metal compound such as gallium nitride (GaN). Various light emitting devices that emit light in white, light bulb color, orange color and the like by combining this light emitting element and phosphor have been developed. These light emitting devices that emit white light and the like are obtained by the principle of light color mixing. For example, a light-emitting device that emits white light using a light-emitting element that emits blue light and a phosphor that emits yellow or the like is required in a wide range of fields such as general lighting, liquid crystal backlights, in-vehicle lighting, and displays. ing.

For example, a fluoride phosphor having a composition of K ₂ SiF ₆ : Mn ⁴⁺ is known as a red-emitting phosphor having an excitation band in the blue region and a narrow half-value width of the emission peak. Various improvements have been studied (for example, see Patent Document 1).

JP 2012-224536 A

However, in the prior art, there is room for improvement in durability when a light-emitting device is configured, and it is insufficient for use in harsh environments such as lighting applications.
In light of the above, an embodiment of the present disclosure aims to provide a red-emitting phosphor excellent in durability, a light-emitting device, and a method for manufacturing the phosphor.

Specific means for solving the above problems are as follows, and the present invention includes the following aspects.
In the first aspect, the composition comprises Mn, at least one selected from the group consisting of alkali metal elements and NH ₄ ^+, and at least one selected from the group consisting of Group 4 elements and Group 14 elements. Preparing phosphor particles containing fluoride, contacting at least one cation selected from rare earth elements with phosphate ions in a liquid medium containing the phosphor particles, A method for producing a phosphor comprising: obtaining rare earth phosphate-attached phosphor particles to which a rare earth phosphate is adhered; and separating the rare earth phosphate-attached phosphor particles from the liquid medium.

In the second aspect, the composition includes Mn, at least one selected from the group consisting of alkali metal elements and NH ₄ ^+, and at least one selected from the group consisting of Group 4 elements and Group 14 elements. A phosphor comprising phosphor particles containing a fluoride and a rare-earth phosphate disposed on the phosphor particles.

  A 3rd aspect is equipped with the fluorescent member containing 1st fluorescent substance and resin, and the light emitting element which has an emission peak wavelength in the wavelength range of 380 nm or more and 470 nm or less, and said 1st fluorescent substance is the fluorescent substance of said 2nd aspect. Is a light emitting device.

  According to an embodiment of the present disclosure, it is possible to provide a red-emitting phosphor, a light-emitting device, and a method for manufacturing the phosphor that are excellent in durability.

3 is a diagram illustrating an example of an SEM image of a phosphor according to Example 1. FIG. It is an example of the elements on larger scale of FIG. 1A. It is a figure which shows an example of the SEM image of the fluorescent substance concerning the comparative example 1. It is an example of the elements on larger scale of Drawing 2A. It is a schematic sectional drawing which shows an example of a light-emitting device.

  Hereinafter, the phosphor, the manufacturing method thereof, 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. In addition, the term “process” is not limited to an independent process, and is included in this term if the intended action of the process is achieved even when it cannot be clearly distinguished from other processes. 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.

Method for Producing Phosphor A method for producing a phosphor according to the first aspect of the present disclosure includes Mn, at least one selected from the group consisting of an alkali metal element and NH ₄ ⁺ , a Group 4 element, and a Group 14 element. Preparing phosphor particles containing a fluoride having a composition having at least one selected from the group consisting of the following (hereinafter also referred to as “preparation step”), and in a liquid medium containing the phosphor particles, Contacting at least one selected cation with phosphate ions to obtain particles in which a rare earth phosphate is attached to the phosphor particles (hereinafter also referred to as “attachment step”, rare earth phosphate) The particles to which the particles are attached are referred to as “rare earth phosphate-attached phosphor particles”), and the rare earth phosphate-attached phosphor particles and the liquid medium are separated (hereinafter also referred to as “separation step”). And including.

A phosphor obtained by attaching a rare earth phosphate to a phosphor particle containing a fluoride having a specific composition by a specific method can exhibit excellent durability when constituting a light emitting device. Durability here refers to, for example, a decrease in output over time even when a phosphor is configured to form a fluorescent member that covers a light emitting element together with a resin, even when a high current is passed through the light emitting element. It means that the chromaticity change is suppressed and the initial performance can be maintained for a long time. Conventionally, it is considered that curing of the resin is hindered by the influence of, for example, an alkali metal contained in the fluoride composition. However, the use of fluoride phosphor particles with rare earth phosphate attached reduces the influence of the fluoride composition, and the resin constituting the phosphor member is sufficiently cured even near the interface with the phosphor. It is thought that the adhesion between the body and the resin is improved. This is considered to be because even when the temperature of the light emitting device rises due to a high current and the resin of the fluorescent member expands, the phosphor and the resin are prevented from peeling off. Note that when the phosphor and the resin peel off in the fluorescent member, a slight gap is formed between the phosphor and the resin, and the amount of excitation light incident on the phosphor decreases due to scattering or the like at the interface. It is considered that the amount of light extracted from the body to the outside of the light emitting device is reduced.
Further, in one embodiment, the adhesion between the phosphor and the resin in the fluorescent member is further improved by exhibiting excellent durability by attaching the rare earth phosphate directly to the phosphor particles in the liquid medium. It is considered possible.

Preparation Step In the preparation step, the composition has Mn, at least one selected from the group consisting of alkali metal elements and NH ₄ ^+, and at least one selected from the group consisting of Group 4 elements and Group 14 elements. Phosphor particles containing fluoride are prepared. The phosphor particles may be appropriately selected from commercially available products and may be prepared by preparing desired phosphor particles.

The phosphor particles containing fluoride include Mn, at least one selected from the group consisting of alkali metal elements and NH ₄ ^+, and at least one selected from the group consisting of Group 4 elements and Group 14 elements. It is preferable that the composition contains at least potassium (K) and silicon (Si). The fluoride preferably has a composition represented by the following formula (1).
^{_{A 2 [M 1-p Mn}} 4+ p F 6] (1)
In the formula (1), A is at least one selected from the group consisting of alkali metal elements and NH ₄ ⁺ . M is at least one selected from the group consisting of Group 4 elements and Group 14 elements. p satisfies 0 <p <0.2.

A in the formula (1) is at least one selected from the group consisting of alkali metal elements and NH ₄ ⁺ , and is lithium (Li), sodium (Na), potassium (K), rubidium (Rb), cesium (Cs And at least one selected from the group consisting of ammonium (NH ₄ ⁺ ), including at least K, and further including at least one selected from the group consisting of Li, Na, Rb, Cs and NH ₄ ⁺ It is more preferable that the alkali metal is mainly composed of K. Here, “having K as a main component” means that the content of K in A in the formula (1) is 80 mol% or more, preferably 90 mol% or more, and preferably 95 mol% or more. It is more preferable that

  M in the formula (1) is at least one selected from the group consisting of Group 4 elements and Group 14 elements, and M is titanium (Ti), zirconium (Zr), hafnium from the viewpoint of light emission characteristics. (Hf), silicon (Si), germanium (Ge), and at least one selected from the group consisting of tin (Sn), preferably silicon (Si), or silicon (Si) and germanium (Ge) More preferably, both are included, and silicon (Si), or silicon (Si) and germanium (Ge) are more preferable.

  When M includes silicon (Si), or silicon (Si) and germanium (Ge), a part of at least one of Si and Ge includes a Group 4 element including Ti, Zr, and Hf, and C and Sn It may be substituted with at least one selected from the group consisting of Group 14 elements. In that case, the total content of Si and Ge in M is, for example, preferably 90 mol% or more, and more preferably 95 mol% or more.

  P in the formula (1) satisfies 0 <p <0.2, and p is, for example, 0.01 or more, 0.015 or more, 0.02 or more, or 0.03 or more from the viewpoint of light emission efficiency and light emission intensity. For example, p is less than 0.2, 0.15 or less, or 0.1 or less. For example, p preferably satisfies 0.01 ≦ p <0.2, more preferably satisfies 0.015 ≦ p ≦ 0.15, and further preferably satisfies 0.02 ≦ p ≦ 0.1. Preferably, 0.03 ≦ p ≦ 0.1 is further satisfied.

  The particle diameter of the phosphor particles is, for example, 1 μm or more, 5 μm or more, or 20 μm or more, and for example, 100 μm or less or 70 μm or less as a volume average particle diameter. The particle size distribution of the phosphor particles is preferably a single peak particle size distribution having a peak within the above range, and more preferably a particle size distribution having a narrow distribution width. By setting the volume average particle size to the above lower limit or more, the light emission intensity and durability can be improved. By setting the volume average particle size to be equal to or less than the above upper limit value, workability in manufacturing the light emitting device can be improved. The volume average particle diameter of the phosphor particles is a particle diameter (median diameter) measured by a laser diffraction particle size distribution analyzer (MASTER SIZER 2000 manufactured by MALVERN).

Fluoride which is a phosphor activated with Mn ⁴⁺ can absorb red light in the short wavelength region of visible light and emit red light. The excitation light that is light in the short wavelength region of visible light is preferably mainly light in the blue region. Specifically, the excitation light preferably has a main peak wavelength of an intensity spectrum in the range of 380 nm to 500 nm, more preferably in the range of 380 nm to 485 nm, and in the range of 400 nm to 485 nm. More preferably, it exists, and it is especially preferable that it exists in the range of 440 nm or more and 480 nm or less. By setting it as said range, the luminous efficiency of fluorescent substance can be improved.

  Moreover, it is preferable that the fluorescent substance containing fluoride exists in the range whose peak wavelength of an emission spectrum is 610 nm or more and 650 nm or less. The half width of the emission spectrum is preferably small, specifically 10 nm or less.

Adhesion process In the adhesion process, at least one cation selected from rare earth elements (hereinafter also referred to as “rare earth metal ions”) and phosphate ions are brought into contact in a liquid medium containing the prepared phosphor particles. Thereby, the rare earth phosphate adheres to the surface of the phosphor particles, and the rare earth phosphate-attached phosphor particles are obtained. By attaching the rare earth phosphate to the phosphor particles in the liquid medium, it is considered that the rare earth phosphate adheres more uniformly to the surface of the phosphor particles, for example.

The liquid medium should just be able to melt | dissolve a phosphate ion and rare earth metal ions, and it is preferable that at least water is included at the point which these ions melt | dissolve easily. The liquid medium may further contain a reducing agent such as hydrogen peroxide, an organic solvent, a pH adjusting agent, 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; 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, 1 to 6, and preferably 1.5 to 4. When the amount is not less than the above lower limit value, a sufficient amount of rare earth phosphate tends to be obtained, and when the amount is not more than the above upper limit value, a decrease in the light emission characteristics of the phosphor tends to be suppressed.
When the liquid medium contains water, the content of water in the liquid medium is, for example, 70% by mass or more, preferably 80% by mass or more, and more preferably 90% by mass or more.

  The mass ratio of the liquid medium with respect to the phosphor particles is, for example, 100% by mass or more or 200% by mass or more, and for example, 1000% by mass or less or 800% by mass or less. When the mass ratio of the liquid medium is equal to or higher than the above lower limit value, it becomes easy to deposit the rare earth phosphate more uniformly on the surface of the phosphor particles, and when the mass ratio of the liquid medium is equal to or lower than the upper limit value, There exists a tendency which the adhesion rate to the fluorescent substance of a salt improves more.

  The liquid medium preferably contains phosphate ions, and more preferably contains water and phosphate ions. When the liquid medium contains phosphate ions, the prepared phosphor particles and the liquid medium are mixed, and further mixed with a solution containing rare earth metal ions, whereby phosphate ions and rare earths are mixed in the liquid medium containing the phosphor particles. Metal ions can be contacted. When the liquid medium contains phosphate ions, the phosphate ion concentration in the liquid medium is, for example, 1% by mass or more, preferably 2% by mass or more, and for example, 10% by mass or less, preferably 7% by mass or less. . When the phosphate ion concentration in the liquid medium is not less than the above lower limit, the amount of the liquid medium does not increase excessively, elution of the composition components from the phosphor is suppressed, and the characteristics of the phosphor tend to be maintained well. . Moreover, there exists a tendency for the uniformity of the deposit | attachment to a fluorescent substance to become favorable as it is below the said upper limit.

  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.

  When the liquid medium contains phosphate ions, the liquid medium may be prepared by dissolving a compound serving as a phosphate ion source, or may be prepared by mixing a solution containing a phosphate ion source and the liquid medium. . 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; Alkali metal dihydrogen phosphates such as sodium hydrogen and potassium dihydrogen phosphate; alkali metal hexametaphosphates such as sodium hexametaphosphate and potassium hexametaphosphate; alkali metal pyrophosphates such as sodium pyrophosphate and potassium pyrophosphate; phosphoric acid Examples thereof include ammonium phosphates such as ammonium.

The liquid medium preferably contains a reducing agent, more preferably contains water and a reducing agent, and further preferably contains water, phosphate ions and a reducing agent. By including a reducing agent in the liquid medium, it is possible to effectively suppress precipitation of manganese dioxide or the like derived from Mn ⁴⁺ contained in the fluoride of the phosphor particles. The reducing agent contained in the liquid medium only needs to be able to reduce Mn ⁴⁺ eluted from the fluoride into the liquid medium, and examples thereof include hydrogen peroxide, oxalic acid, and hydroxyamine hydrochloride. Of these, hydrogen peroxide is preferable because it is decomposed into water and does not adversely affect the fluoride.

  When the liquid medium contains a reducing agent, the liquid medium may be prepared by dissolving a compound that becomes a reducing agent, or may be prepared by mixing a solution containing the reducing agent and the liquid medium. The content of the reducing agent in the liquid medium is not particularly limited, but is, for example, 0.1% by mass or more and preferably 0.3% by mass or more for the above reason.

  In addition to Sc and Y, rare earth elements to be rare earth metal ions to be brought into contact with phosphate ions include La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, and Yb. And at least one selected from lanthanoids, more preferably at least one selected from the group consisting of La, Ce, Dy and Gd.

  The contact between the phosphate ion and the rare earth metal ion in the liquid medium may be performed, for example, by dissolving a compound serving as the rare earth metal ion source in the liquid medium containing the phosphate ion. And a solution containing rare earth metal ions may be mixed. The solution containing rare earth metal ions can be prepared, for example, by dissolving a compound that becomes a rare earth metal ion source in a solvent such as water. The compound serving as the rare earth metal ion source is, for example, a metal salt containing a rare earth element, and examples of the anion constituting the metal salt include nitrate ion, sulfate ion, acetate ion, and chloride ion.

  The contact between phosphate ions and rare earth metal ions in the liquid medium is, for example, a phosphor slurry containing phosphoric acid ions, preferably further containing a reducing agent to obtain a phosphor slurry, Mixing with a solution containing phosphor slurry and rare earth metal ions.

  The content of rare earth metal ions in the liquid medium in which phosphate ions and rare earth metal ions are brought into contact is, for example, 0.05% by mass or more or 0.1% by mass or more, and for example, 3% by mass or less or 2% by mass. It is as follows. Moreover, the content rate of the rare earth metal ion with respect to the amount of phosphor particles in the liquid medium is, for example, 0.2% by mass or more or 0.5% by mass or more, and for example, 30% by mass or less or 20% by mass or less. If the concentration of the rare earth metal ion is not less than the above lower limit value, the adhesion rate of the rare earth phosphate to the phosphor tends to be further improved, and if the concentration of the rare earth metal ion is not more than the above upper limit value, There is a tendency that the salt is more easily adhered to the phosphor particle surface more uniformly.

  The contact temperature between the phosphate ions forming the rare earth phosphate and the rare earth metal ions is, for example, 10 ° C. to 50 ° C., 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.

Separation process In the separation process, the rare earth phosphate-attached phosphor particles and the liquid medium are separated to obtain a desired phosphor. Separation can be performed, for example, by solid-liquid separation means such as filtration and centrifugation. The phosphor obtained by solid-liquid separation may be subjected to washing treatment, drying treatment and the like as necessary. The cleaning treatment can be performed using, for example, an alcohol such as ethanol or isopropyl alcohol, a ketone solvent such as acetone, or water. The drying treatment 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 drying time can be, for example, 8 hours to 20 hours.

The phosphor of the second aspect of the present disclosure is at least one selected from the group consisting of Mn, at least one selected from the group consisting of alkali metal elements and NH ₄ ^+, and Group 4 elements and Group 14 elements. Phosphor particles (hereinafter also referred to as “core particles”) containing a fluoride having one type of composition, and rare earth phosphates arranged on the phosphor particles. By arranging the rare earth phosphate in the phosphor particles, for example, in the fluorescent member constituting the light emitting device, the adhesion and adhesion between the phosphor and the resin are improved, and the light emitting device has excellent durability. Can be configured.

  The details of the phosphor particles containing the fluoride constituting the phosphor and the rare earth phosphate are as described above. In the phosphor, the rare earth phosphate is attached to the core particle. Attachment of the rare earth phosphate to the core particle may be due to any of physical interaction such as van der Waals force, electrostatic interaction, chemical interaction due to partial chemical reaction, etc. . Further, the rare earth phosphate may be adhered in the form of particles or may be adhered in the form of a film. From the viewpoint of durability, at least a part of the rare earth phosphate is preferably adhered in the form of a film. Here, that the rare earth phosphate is arranged in a film form means that the surface of the core particle is covered with the rare earth phosphate at 50% or more, preferably 70% or more of the area.

  The arrangement amount of the rare earth phosphate in the phosphor is, for example, 0.05% by mass or more, 0.1% by mass or more, 0.5% by mass or more, 0.8% by mass or more, and 1% by mass as the content of the rare earth metal element. % Or more, or 2 mass% or more. Moreover, the content rate of rare earth metal elements is 20 mass% or less, 16 mass% or less, 14 mass% or less, 10 mass% or less, or 8 mass% or less, for example. Sufficient durability tends to be obtained when the amount of the rare earth phosphate is not less than the above lower limit. Moreover, when the amount is not more than the above upper limit value, a decrease in light emission characteristics as a phosphor tends to be suppressed.

  Here, the contents of rare earth metal elements and phosphate ions constituting the rare earth phosphate in the phosphor can be measured using ICP-AES (High Frequency Inductively Coupled Plasma Emission Spectroscopy).

  The particle size and particle size distribution of the phosphor reflect those characteristics of the core particles described above. The particle diameter of the phosphor is, for example, 1 μm or more, 5 μm or more, or 20 μm or more as a volume average particle diameter, and for example, 100 μm or less, or 70 μm or less. By setting it to the above lower limit or more, the light emission intensity and the durability tend to be improved. By setting it to the upper limit value or less, workability when manufacturing the light emitting device tends to be improved.

Light-emitting device The light-emitting device includes the phosphor (hereinafter also referred to as “first phosphor”) and a resin, and a light-emitting element having an emission peak wavelength in a wavelength range of 380 nm to 470 nm. By combining a fluorescent member containing the phosphor and a light emitting element, a light emitting device having excellent durability can be configured. The fluorescent member may further include a second phosphor having an emission peak wavelength in a wavelength range of 500 nm or more and 580 nm or less.

A light emitting device 100 according to an embodiment of the present invention will be described with reference to the drawings. FIG. 3 is a schematic cross-sectional view showing the light emitting device 100. 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. For example, as shown in FIG. 3, the fluorescent member 50 includes a first phosphor 71, a second phosphor 72, and a resin as the phosphor 70.

  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 FIG. 3, 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.

Light-Emitting Element The emission peak wavelength of the light-emitting element is in the range of 380 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 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.

Fluorescent member The light emitting device includes a fluorescent member containing a first phosphor and a resin. The fluorescent member forms a light emitting device by covering, for example, a light emitting element. The details of the first phosphor are the same as those of the phosphor of the second embodiment described above, and the preferred embodiments are also the same. 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. Examples of the silicone resin include at least one selected from the group consisting of methylsilicone, dimethylsilicone, methylphenylsilicone, phenylsilicone, diphenylsilicone, and fluorosilicone.

  The content of the first phosphor in the fluorescent member 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. 160 mass% or less is preferable and 130 mass% or less is more preferable.

  In addition to the first phosphor, the light emitting device may include at least one second phosphor having an emission peak wavelength different from that of the first phosphor in the fluorescent member. By having the second phosphor, a light emitting device capable of emitting light of various hues can be configured.

Specific examples of the second phosphor include phosphors having a composition represented by any of the following formulas (I) to (IX). The second phosphor may be used alone or in combination of two or more. Examples of the second phosphor include at least one selected from the following formulas (IV), (V), (VII), and (VIII) as phosphors having an emission peak wavelength in the wavelength range of 500 nm to 580 nm. Can do. In particular, by selecting a phosphor having a composition represented by the following formula (V) or the following formula (VII) as the second phosphor and including it in the fluorescent member together with the first phosphor, for example, the following formula (VIII) ) Is preferable in that the color reproducibility in the liquid crystal display device including the light emitting device can be improved, rather than selecting the phosphor having the composition represented by (2) as the second phosphor. Moreover, it is preferable that a phosphor having a composition represented by the following formula (VIII) is selected as the second phosphor in that a light emitting device with higher luminous efficiency can be configured.
_{(Ca 1-p-q Sr} p Eu q) AlSiN 3 (I)
In formula (I), p and q satisfy 0 ≦ p ≦ 1, 0 <q <1 and p + q <1.

_{(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 ≦ s ≦ 1, 0 <t <1, and r + s + t ≦ 1.

(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+ (III)
In the formula (III), 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 are satisfied.

M ¹¹ ₈ MgSi ₄ O ₁₆ X ¹¹ ₂ : Eu (IV)
In formula (IV), 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 (V)
In the formula (V), z satisfies 0 <z <4.2.

_{M m / n Si 12- (m} + n) Al (m + n) O n N (16-n): Eu (VI)
In formula (VI), 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 (VII)
Wherein ^{(VII), M 13} is at least one selected from Mg, Ca, the group consisting of Sr and Ba.

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

_{^{M a v M b w M c}} x Al 3-y Si y N z (IX)
In formula (IX), 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, and 3 ≦ z ≦ 5 are satisfied.

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

  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 The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

(Method for producing phosphor particles)
16.2 g of K ₂ MnF ₆ was weighed and dissolved in 1000 g of a 55% by mass HF aqueous solution to prepare a solution A. Further, 195.10 g of KHF ₂ was weighed and dissolved in 200 g of a 55% by mass HF aqueous solution to prepare a solution B. A solution C was prepared by weighing 450 g of 40% by mass H ₂ SiF ₆ aqueous solution.
Next, Solution A and Solution C were added dropwise over about 20 minutes while stirring Solution A at room temperature. The obtained precipitate is subjected to solid-liquid separation, followed by washing with IPA (isopropyl alcohol) and drying at 70 ° C. for 10 hours, whereby phosphor particles containing a fluoride having a composition represented by formula (1) (core) Particles).

Example 1
A sodium salt solution of phosphoric acid (phosphoric acid concentration: 2.4% by mass) and 2.6 g of 30% by mass of hydrogen peroxide water were placed in a beaker, and pure water was added to make 150 g. While stirring this, 50 g of the prepared core particles were added to obtain a phosphor slurry. To the phosphor slurry, 20 g of a lanthanum nitrate solution (lanthanum concentration: 5.0 mass%) was added and sufficiently stirred. At this time, the occurrence of precipitation of lanthanum phosphate was confirmed in the phosphor slurry. Next, the phosphor slurry was dehydrated by filtration and dried to obtain the target phosphor 1.
The phosphor 1 had 1.1% by mass of lanthanum phosphate attached as the amount of lanthanum.

(Example 2)
256.4 g of a sodium salt solution of phosphoric acid (phosphoric acid concentration: 2.4% by mass) and 2.5 g of 30% by mass of hydrogen peroxide were placed in a beaker. While stirring this, 50 g of the prepared core particles were added to obtain a phosphor slurry. To the phosphor slurry, 50 g of a lanthanum nitrate solution (lanthanum concentration: 5.0 mass%) was added and sufficiently stirred. At this time, the occurrence of precipitation of lanthanum phosphate was confirmed in the phosphor slurry. Next, the phosphor slurry was dehydrated by filtration and dried to obtain the target phosphor 2.
On phosphor 2, 2.9% by mass of lanthanum phosphate was adhered as the amount of lanthanum.

(Example 3)
Example 2 except that the amount of sodium salt solution of phosphoric acid (phosphoric acid concentration: 2.4% by mass) used was 512.8 g and the lanthanum nitrate solution (lanthanum concentration: 5.0% by mass) was 100 g. Similarly, the phosphor 3 was obtained.
On phosphor 3, 4.8% by mass of lanthanum phosphate was adhered as the amount of lanthanum.

Example 4
Example 3 except that the amount of sodium salt solution of phosphoric acid (phosphoric acid concentration: 2.4% by mass) used was 1025.6 g and the lanthanum nitrate solution (lanthanum concentration: 5.0% by mass) was 200 g. Similarly, the phosphor 4 was obtained.
The phosphor 4 had 6.7% by mass of lanthanum phosphate attached as the amount of lanthanum.

(Comparative Example 1)
As the phosphor C1 of Comparative Example 1, the prepared core particles were used as they were.

(Comparative Example 2)
100 g of core particles and 9.5 g of calcium pyrophosphate powder were added to 180 g of ethanol and suspended. To this, 36.0 g of pure water and 36.0 g of Si (OEt) ₄ were added, and further, 43.2 g of aqueous ammonia was added as a catalyst for hydrolysis. Thereafter, dehydration treatment and drying treatment were performed to obtain phosphor C2 in which calcium pyrophosphate was coated with silicon dioxide by a sol-gel method on the surface of the phosphor particles.
The phosphor C2 had 2.0% by mass calcium phosphate as the amount of calcium.

(Example 5)
25.64 g of phosphoric acid sodium salt solution (phosphoric acid concentration: 2.4 mass%) and 2.5 g of 30 mass% hydrogen peroxide water were placed in a beaker, and pure water was added to make 150 g. While stirring this, 50 g of the prepared core particles were added to obtain a phosphor slurry. To the phosphor slurry, 30 g of a lanthanum nitrate solution (lanthanum concentration: 5.0 mass%) was added and sufficiently stirred. At this time, the occurrence of precipitation of lanthanum phosphate was confirmed in the phosphor slurry. Next, the phosphor slurry was dehydrated by filtration and dried to obtain the target phosphor 5.
The phosphor 5 had 2.3% by mass of lanthanum phosphate attached as the amount of lanthanum.

(Example 6)
The amount of sodium salt solution of phosphoric acid (phosphoric acid concentration: 2.4% by mass) is 51.28 g, pure water is added to 300 g, and the lanthanum nitrate solution (lanthanum concentration: 5.0% by mass) is 60 g. A phosphor 6 was obtained in the same manner as in Example 5 except that.
The phosphor 6 had 5.2% by mass of lanthanum phosphate attached as the amount of lanthanum.

(Example 7)
The amount of sodium phosphate solution (phosphoric acid concentration: 2.4% by mass) used was 76.91 g, pure water was added to 450 g, and the lanthanum nitrate solution (lanthanum concentration: 5.0% by mass) was 90 g. A phosphor 7 was obtained in the same manner as in Example 5 except that.
On the phosphor 7, 7.6% by mass of lanthanum phosphate was adhered as the amount of lanthanum.

(Example 8)
The amount of sodium salt solution of phosphoric acid (phosphoric acid concentration: 2.4 mass%) is 102.55 g, pure water is added to 600 g, and the lanthanum nitrate solution (lanthanum concentration: 5.0 mass%) is 120 g. A phosphor 8 was obtained in the same manner as in Example 5 except that.
The phosphor 8 had 9.7% by mass of lanthanum phosphate attached as the amount of lanthanum.

Example 9
The amount of sodium salt solution of phosphoric acid (phosphoric acid concentration: 2.4% by mass) is 128.19 g, pure water is added to 750 g, and the lanthanum nitrate solution (lanthanum concentration: 5.0% by mass) is 150 g. A phosphor 9 was obtained in the same manner as in Example 5 except that.
The phosphor 9 had 12.0% by mass of lanthanum phosphate attached as the amount of lanthanum.

Production of Light-Emitting Device a Fluorescence whose composition is Y ₃ Al ₅ O ₁₂ : Ce for phosphors 1 to 4 obtained in Examples 1 to 4 and phosphors C1 and C2 obtained in Comparative Examples 1 and 2 The light-emitting device a was produced as follows in combination with the body (second phosphor).
Phosphors 1 to 4, C1 or C2, and the second phosphors whose blending amounts are adjusted so that the chromaticity coordinates of light emitted from the light emitting device a are in the vicinity of x = 0.380 and y = 0.380 are made of silicone resin. After adding, mixing and dispersing, the resin composition was obtained by further defoaming. Next, this resin composition was injected and filled onto a light emitting element (emission peak wavelength 455 nm) of an LED package, and further heated at 150 ° C. for 4 hours to cure the resin composition. Through these steps, light emitting devices a including the phosphors obtained in Examples 1 to 4 and Comparative Examples 1 and 2 were produced. Hereinafter, the light emitting device a including any one of the phosphors 1 to 4 is referred to as Examples 1a to 4a, and the light emitting device a including the phosphors C1 or C2 is referred to as Comparative Example 1a or Comparative Example 2a.

Durability Evaluation The obtained light-emitting device a was continuously lit at a current of 250 mA in a high-temperature environmental test machine at 85 ° C., and the difference from the initial value of x and y values in the chromaticity coordinates after 700 hours was expressed as Δx, Δy As evaluated. Similarly, the relative light flux after 700 hours was evaluated together with the initial value of the light flux as 100 as a relative value. The evaluation results are shown in Table 1.

From Table 1, it can be seen that in the light emitting devices according to Examples 1a to 4a, Δy is zero, that is, there is no change in the y value from the initial value in the chromaticity coordinates, and the durability is superior to Comparative Examples 1a and 2a. In Examples 1a to 4a, Δy is a numerical difference of 0.01 compared to Comparative Example 2a, but the difference in color tone is actually large when viewed with the naked eye.
The SEM images of the phosphor 1 are shown in FIGS. 1A and 1B, and the SEM images of the phosphor C1 are shown in FIGS. 2A and 2B. Compared with FIGS. 2A and 2B, as shown in FIGS. 1A and 1B, it can be seen that phosphor 1 has lanthanum phosphate attached to the surface of the core particle at least in the form of particles or films. Thereby, when the phosphor 1 was mixed with the resin to form the phosphor member, the adhesion between the phosphor and the resin in the phosphor member was further improved, and thus it was considered that excellent durability was exhibited.

Production of Light-Emitting Device b Fluorescence whose composition is Sr _0.88 Eu _0.12 Ga ₂ S ₄ for phosphors 5 to 9 obtained in Examples 5 to 9 and phosphor C1 obtained in Comparative Example 1 In combination with the body (second phosphor), a light emitting device b was produced as follows.
Phosphors 5 to 9 or C1 and the second phosphor whose mixing amount is adjusted so that the chromaticity coordinates of the light emitted from the light emitting device b are in the vicinity of x = 0.280 and y = 0.270, and silica nanoparticles Was added to the silicone resin, mixed and dispersed, and then defoamed to obtain a resin composition. Next, this resin composition was injected and filled on a light emitting element (emission peak wavelength 455 nm) of an LED package, and then phosphor particles were precipitated by centrifugal sedimentation. Furthermore, the resin composition was hardened by heating at 150 degreeC for 4 hours. Through such steps, the light emitting devices b including the phosphors obtained in Examples 5 to 9 and Comparative Example 1 were produced. Hereinafter, the light emitting devices b including any of the phosphors 5 to 9 are referred to as Examples 5b to 9b, respectively, and the light emitting device b including the phosphor C1 is referred to as a comparative example 1b.

Durability evaluation The obtained light-emitting device b was stored in an environmental test machine without lighting, at a temperature of 85 ° C. and a relative humidity of 85%, and after 1000 hours had elapsed, it was lit at a current of 20 mA, and the color before storage Differences from initial values of x and y values in degree coordinates were evaluated as Δx and Δy. Similarly, the relative light flux after storage for 1000 hours was evaluated as a relative value with the initial value of the light flux before storage as 100. The evaluation results are shown in Table 2.

  From Table 2, in the light-emitting device b according to Examples 5b to 9b, the absolute value of Δy is smaller than that of Comparative Example 1b, that is, the change of the y value from the initial value in the chromaticity coordinates is small, which is higher than that of Comparative Example 1b. It can be seen that the storage durability is excellent in a high humidity environment. Also, the relative luminous flux is higher than that of Comparative Example 1b.

  A phosphor having excellent durability can be obtained by the manufacturing method of the present disclosure. The phosphor of the present disclosure can be used for a light-emitting device, and the light-emitting device of the present disclosure has excellent durability, uses a light-emitting diode as an excitation light source, a display, a light source for backlight, general illumination, and in-vehicle illumination. It can be used in a wide range of fields.

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

Claims (13)

Phosphor containing a fluoride having in composition Mn, at least one selected from the group consisting of alkali metal elements and NH ₄ ^+, and at least one selected from the group consisting of Group 4 elements and Group 14 elements Preparing the particles,
Attachment of rare earth phosphate in which at least one cation selected from rare earth elements and phosphate ions are brought into contact with each other in the liquid medium containing the phosphor particles, and the rare earth phosphate is attached to the phosphor particles. Obtaining phosphor particles;
Separating the rare earth phosphate-attached phosphor particles and the liquid medium;
The manufacturing method of the fluorescent substance containing this.   The manufacturing method according to claim 1, wherein the liquid medium includes the phosphate ions, the liquid medium and a solution including the cations are mixed, and the cations and the phosphate ions are brought into contact with each other.   The manufacturing method according to claim 1, further comprising mixing the phosphor particles and a liquid medium containing the phosphate ions and a reducing agent to obtain a liquid medium containing the phosphor particles.   The manufacturing method of Claim 3 with which the said reducing agent contains hydrogen peroxide. The manufacturing method according to any one of claims 1 to 4, wherein the fluoride has a composition represented by the following formula (1).
A ₂ [M _1-p Mn ⁴⁺ _p F ₆ ] (1)
(Wherein, A is at least one selected from the group consisting of alkali metal elements and NH ₄ ⁺ , M is at least one selected from the group consisting of Group 4 elements and Group 14 elements, p satisfies 0 <p <0.2.) Phosphor containing a fluoride having in composition Mn, at least one selected from the group consisting of alkali metal elements and NH ₄ ^+, and at least one selected from the group consisting of Group 4 elements and Group 14 elements A phosphor comprising particles and a rare earth phosphate disposed on the phosphor particles. The phosphor according to claim 6, wherein the fluoride has a composition represented by the following formula (1).
A ₂ [M _1-p Mn ⁴⁺ _p F ₆ ] (1)
(Wherein, A is at least one selected from the group consisting of alkali metal elements and NH ₄ ⁺ , M is at least one selected from the group consisting of Group 4 elements and Group 14 elements, p satisfies 0 <p <0.2.)   The phosphor according to claim 6 or 7, wherein the composition contains at least K and Si.   The phosphor according to any one of claims 6 to 8, wherein the rare earth phosphate contains a lanthanoid.   The phosphor according to claim 9, wherein the lanthanoid is at least one selected from the group consisting of La, Ce, Dy, and Gd.   The phosphor according to any one of claims 6 to 10, wherein a content of the rare earth metal element constituting the rare earth phosphate is 0.1 mass% or more and 20 mass% or less. A fluorescent member comprising a first phosphor and a resin, and a light emitting element having an emission peak wavelength in a wavelength range of 380 nm to 470 nm,
The light-emitting device in which said 1st fluorescent substance contains the fluorescent substance of any one of Claim 6 to 11.   The light emitting device according to claim 12, wherein the fluorescent member further includes a second phosphor having an emission peak wavelength in a wavelength range of 500 nm or more and 580 nm or less.