JP2015183085A - Phosphor, phosphor-containing composition, light-emitting device, luminaire, and liquid crystal display device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a blue-luminescent alkaline-earth chlorophosphate phosphor having a high excitation intensity in an excitation wave length range at 380-430 nm, and having a high luminance when in a powder form.SOLUTION: The phosphor is represented by the formula [1]: SrBaEu)(PO)Clwhere 1≤a≤9.68, 0.02<b≤3, 0.3≤c≤2, and a+b+c=10, and coated with a compound containing at least one element selected from the group consisting of Y, La, Lu, and Gd. A phosphor conversion type light-emitting device includes a semiconductor light emitting element emitting light in a wave length range from 380 nm to 430 nm, and the phosphor, and emits light generated by wavelength-converting the light emitted by the semiconductor light emitting element with the phosphor.

Description

  The present invention relates to a phosphor that emits light by excitation with ultraviolet rays or violet light having a wavelength of 380 nm to 430 nm and has high powder brightness, a phosphor-containing composition containing the phosphor, and the phosphor in combination with an ultraviolet to purple LED. Thus, the present invention resides in a light emitting device, a lighting device, and a liquid crystal display device that have high luminous efficiency and good color rendering over a long period of time.

  In recent years, various light emitting diodes and laser diodes have been developed as semiconductor light emitting devices (LEDs). In particular, LED chips using nitride semiconductors have been developed as LED chips that can emit light efficiently on the short wavelength side from the ultraviolet region to the visible light region.

  On the LED chip, a phosphor that absorbs a part of the primary light from the LED chip and emits light is disposed, and an LED that emits various emission colors including white has been developed.

  A typical example of the white LED is an LED in which a blue light emitting LED chip and a yellow phosphor (for example, yttrium, aluminum, garnet phosphor: YAG phosphor) are combined. However, since the LED emits white light with two colors of blue light emission and yellow light emission, the light emission is bluish light, the color rendering property is not sufficient, and further improvement has been demanded.

  In order to improve the color rendering, it is conceivable to obtain white light closer to natural light by mixing the three primary colors of light, blue, green, and red. As this configuration, for example, a combination of an LED chip that emits primary light from the ultraviolet region to the visible light region and a phosphor that emits red, blue, and green light when excited by the primary light can be given.

  Among LED chips, chips having an emission peak from 380 nm to 430 nm have been developed in recent years. Therefore, a white LED in which this LED chip is combined with red, blue and green phosphors has been developed.

Various blue phosphors used for this white LED have been developed. For example, in Patent Document 1, Eu ²⁺ activated barium magnesium aluminate phosphor and Eu ²⁺ activated alkaline earth chlorophosphate phosphor Is disclosed.
In addition, as a blue light emitting phosphor for a cold cathode fluorescent lamp having a wide color reproduction range when used as a backlight for a liquid crystal display or the like instead of a white LED, Patent Document 2 discloses Eu ²⁺ activated alkaline earth chlorophosphoric acid. A salt-based phosphor is disclosed.

JP 2013-12711 A International Publication No. 2007/074935 Pamphlet

However, the phosphors described in Patent Documents 1 and 2 sometimes have low excitation intensity in the excitation wavelength region from 380 nm to 430 nm. For this reason, in the light emitting device in which the phosphor described in Patent Document 1 is combined with an LED chip having a light emission peak from 380 nm to 430 nm, sufficient light emission efficiency may not be obtained.
In addition, when the present inventors use the phosphors described in Patent Documents 1 and 2 in a light emitting device including an LED chip having a light emission peak at a wavelength of 380 nm to 430 nm, a color shift of a light emission color with time occurs. Or found that the luminous flux maintenance factor of the light emitting device may not be sufficient.
Furthermore, it has also been found that the Eu ²⁺ activated alkaline earth chlorophosphate phosphor does not have sufficient powder luminance, and the light emission efficiency of a light emitting device using the powder is not sufficient.

Note that Patent Document 2 discloses that phosphors used in cold cathode fluorescent lamps have problems of light flux reduction due to mercury adsorption and color shift caused by ultraviolet rays.
In other words, the alkaline earth chlorophosphate phosphor described in Patent Document 2 is a cold material considering that its use is excited by ultraviolet rays having a shorter excitation wavelength than conventional fluorescent lamps (for example, ultraviolet rays having a wavelength of 185 nm). Since it is a cathode fluorescent lamp, the concentration of europium (Eu) as an activator is 0.27 mol at the maximum.
On the other hand, the phosphor of the present invention is an alkaline earth chlorophosphate phosphor excited mainly by an LED chip that emits ultraviolet or violet light having a longer wavelength than the fluorescent lamp, and its Eu concentration is at least 0.3 mol. That's it.
Conventionally, there has been no study on the suppression of the LED luminous flux maintenance factor and the color shift over time in an alkaline earth chlorophosphate phosphor having an Eu concentration of 0.3 mol or more.
That is, this document does not present a problem when the alkaline earth chlorophosphate phosphor is used for an LED whose excitation light does not include ultraviolet light having a short wavelength (for example, ultraviolet light having a wavelength of 185 nm).

The present invention has been made in view of the above circumstances, and has a blue-emitting alkaline earth chlorophosphate phosphor having high excitation intensity in the excitation wavelength region of 380 to 430 nm and high luminance when powdered. It is an issue to provide.
The present invention also provides a light-emitting device using the phosphor of the present invention and an LED chip having a light emission peak from 380 nm to 430 nm, which is less likely to cause a color shift of the emitted color over time and has a good luminous flux maintenance factor. This is the issue.
Furthermore, the present invention provides a high-quality lighting device and liquid crystal display device using this light-emitting device.

  As a result of intensive studies, the present inventors have found that the above problems can be solved by using an alkaline earth chlorophosphate phosphor containing a specific element as a coating component, and have reached the present invention.

That is, the gist of the present invention is a phosphor represented by the following formula [1], which is one or more elements selected from the group consisting of Y, La, Lu and Gd (hereinafter referred to as “coating element”). In a phosphor characterized by being coated with a compound (hereinafter referred to as “coating material”).
(Sr _a Ba _b Eu _c ) (PO ₄ ) ₆ Cl ₂ [1]
(In Formula [1], a, b, c, and d are values in the following ranges, respectively.
1 ≦ a ≦ 9.68
0.02 <b ≦ 3
0.3 ≦ c ≦ 2
a + b + c = 10)

The gist of the present invention also includes a phosphor-containing composition comprising the phosphor of the present invention and a liquid medium,
A phosphor conversion type light emitting device including a semiconductor light emitting element that emits light in a wavelength region of 380 nm to 430 nm and a phosphor, and generates light obtained by wavelength-converting light emitted from the semiconductor light emitting element with the phosphor. And the phosphor is the phosphor of the present invention,
An illumination device comprising the light-emitting device of the present invention as a light source;
And a liquid crystal display device comprising the light-emitting device of the present invention as a light source,
Exist.

ADVANTAGE OF THE INVENTION According to this invention, it becomes possible to provide the alkaline earth chlorophosphate fluorescent substance of blue light emission with high excitation intensity | strength in the excitation wavelength range in 380-430 nm, and the high brightness | luminance at the time of powder.
In addition, according to the present invention, the phosphor of the present invention is included, so that when used in a light-emitting device including an LED chip having an emission peak from 380 nm to 430 nm, a color shift of the emission color with time is unlikely to occur. It is possible to provide a light emitting device having a good maintenance rate.
Furthermore, according to the present invention, it is possible to provide an illumination device and a liquid crystal display device having the high-quality light-emitting device.

It is a typical perspective view which shows one Example of the light-emitting device of this invention. FIG. 2A is a schematic cross-sectional view showing an embodiment of a bullet-type light emitting device of the present invention, and FIG. 2B is a schematic view showing an embodiment of the surface-mounted light-emitting device of the present invention. It is sectional drawing. It is typical sectional drawing which shows one Example of the illuminating device of this invention.

Hereinafter, the present invention will be described with reference to embodiments and examples. However, the present invention is not limited to the following embodiments and examples, and may be arbitrarily modified without departing from the gist of the present invention. Can be implemented.
In the phosphor composition formulas in this specification, each composition formula is delimited by a punctuation mark (,). In addition, when a plurality of elements are listed separated by commas (,), one or two or more of the listed elements may be included in any combination and composition. For example, the composition formula “(Ca, Sr, Ba) Al ₂ O ₄ : Eu” has “CaAl ₂ O ₄ : Eu”, “SrAl ₂ O ₄ : Eu”, and “BaAl ₂ O ₄ : Eu”. “Ca _1−x Sr _x Al ₂ O ₄ : Eu”, “Sr _1−x Ba _x Al ₂ O ₄ : Eu”, “Ca _1−x Ba _x Al ₂ O ₄ : Eu”, _{"Ca 1-x-y Sr x} Ba y Al 2 O 4: Eu " and all assumed to generically indicated (in the above formula, 0 <x <1,0 <y <1,0 <X + y <1).

[Composition of phosphor]
The phosphor of the present invention has a composition represented by the following formula [1] and is coated with a coating material described later.
(Sr _a Ba _b Eu _c ) (PO ₄ ) ₆ Cl ₂ [1]
(In Formula [1], a, b, c, and d are values in the following ranges, respectively.
1 ≦ a ≦ 9.68
0.02 <b ≦ 3
0.3 ≦ c ≦ 2
a + b + c = 10)

In the formula [1], “Sr” represents a strontium element, and “Ba” represents a barium (Ba) element.
Sr and Ba may each partially contain other elements such as magnesium (Mg) and calcium (Ca) elements.

  In the formula [1], “Eu” represents a europium element. Eu is a part of other elements such as yttrium (Y), lanthanum (La), gadolinium (Gd), terbium (Tb), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium ( Sm), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), or one or more of rare earth elements such as ytterbium (Yb) may be contained.

  In the formula [1], “P” represents a phosphorus element. P may partially contain other elements such as silicon (Si), aluminum (Al), boron (B) and the like.

  In the formula [1], “O” represents an oxygen element, and “Cl” represents a chlorine element. O and Cl may each partially contain other elements such as fluorine (F) and bromine (Br).

  In addition to the constituent elements described above, the phosphor of the present invention may contain other elements within a range that does not affect the effects of the present invention.

In the formula [1], a is usually a number that satisfies 1 ≦ a ≦ 9.68, and the lower limit is preferably 2, more preferably 3, and the upper limit is preferably 9.5. 9 is more preferable.
b is a number that usually satisfies 0.02 <b ≦ 3, and the lower limit is preferably 0.05, more preferably 0.1, and the upper limit is preferably 2.7, more preferably 2.5.
c is a number that usually satisfies 0.3 ≦ c ≦ 2, and its lower limit is preferably 0.5, more preferably 0.7, and its upper limit is preferably 1.7, more preferably 1.5.
Note that a, b, and c satisfy a + b + c = 10.
It is preferable that a, b, and c are within the above ranges in that the obtained phosphor has blue to green light emission and good emission luminance.

[Fluorescent coating material]
In the phosphor of the present invention, the phosphor represented by the formula [1] (that is, a core phosphor described later) is composed of yttrium (Y), lanthanum (La), lutetium (Lu), and gadolinium (Gd). It is coated with a compound (hereinafter referred to as “coating material”) containing one or more elements selected from the group (hereinafter referred to as “coating element”).
In particular, the coating material preferably contains an yttrium element and / or a lanthanum element. That is, the covering element is preferably Y and / or La.

  In the present invention, “coating” does not necessarily mean that the entire surface of the phosphor is covered, and a state in which a coating substance adheres to at least a part of the surface of the phosphor is referred to as “coating”.

  As the coating material, in addition to the yttrium (Y), lanthanum (La), lutetium (Lu), and gadolinium (Gd), europium (Eu), terbium (Tb) within a range that does not affect the light emission characteristics of the phosphor. ), Cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), etc. One or more elements may be contained.

As the coating material, known materials can be used, and oxides, hydroxides, carbonates, oxalates, phosphates and borates containing one or more of Y, La, Lu and Gd. , Fluorides, organic complexes, etc., oxides containing one or more of Y, La, Lu, and Gd, water, in terms of high reflectivity, low reactivity, stability, and excellent coating effect. It is preferable that it is 1 type, or 2 or more types chosen from the group of an oxide, carbonate, and oxalate. This also applies to the above elements that may be contained in addition to Y, La, Lu, and Gd.
These oxides, hydroxides, carbonates, and oxalates may be condensates or hydrates.

Specific examples of the coating material containing Y include yttrium oxide (Y ₂ O ₃ ), yttrium hydroxide (Y (OH) ₃ ), yttrium carbonate (Y ₂ (CO ₃ ) ₃ ), and yttrium oxalate (Y ₂ (C ₂ O ₄ ) ₃ ), yttrium fluoride (YF ₃ ), yttrium borate (YBO ₃ ), yttrium phosphate (YPO ₄ ) and the like, and double salts and hydrates thereof may be used. Furthermore, an organic complex of yttrium may be used. Among these, yttrium hydroxide (Y (OH) ₃ ) and yttrium oxide (Y ₂ O ₃ ) are preferable.

Specific examples of coating materials containing La include lanthanum oxide (La ₂ O ₃ ), lanthanum hydroxide (La (OH) ₃ ), lanthanum carbonate (La ₂ (CO ₃ ) ₃ ), lanthanum oxalate (La ₂ (C ₂ O ₄ ) ₃ ), lanthanum fluoride (LaF ₃ ), lanthanum borate (LaBO ₃ ), lanthanum phosphate (LaPO ₄ ) and the like. These double salts and hydrates may also be used. Further, an organic complex of lanthanum may be used. Among these, lanthanum hydroxide (La (OH) ₃ ) and lanthanum oxide (La ₂ O ₃ ) are preferable.

Specific examples of the coating material containing Lu include lutetium oxide (Lu ₂ O ₃ ), lutetium hydroxide (Lu (OH) ₃ ), lutetium carbonate (Lu ₂ (CO ₃ ) ₃ ), and lutetium oxalate (Lu ₂ (C ₂ O ₄ ) ₃ ), lutetium fluoride (LuF ₃ ), lutetium borate (LuBO ₃ ), lutetium phosphate (LuPO ₄ ) and the like. These double salts and hydrates may also be used. Furthermore, an organic complex of lutetium may be used. Among these, lutetium hydroxide (Lu (OH) ₃ ) and lutetium oxide (Lu ₂ O ₃ ) are preferable.

Specific examples of coating materials containing Gd include gadolinium oxide (Gd ₂ O ₃ ), gadolinium hydroxide (Gd (OH) ₃ ), gadolinium carbonate (Gd ₂ (CO ₃ ) ₃ ), gadolinium oxalate (Gd ₂ (C ₂ O ₄ ) ₃ ), gadolinium fluoride (GdF ₃ ), gadolinium borate (GdBO ₃ ), gadolinium phosphate (GdPO ₄ ), and the like. These double salts and hydrates may also be used. Furthermore, an organic complex of gadolinium may be used. Among these, gadolinium oxide (Gd (OH) ₃ ) and gadolinium oxide (Gd ₂ O ₃ ) are preferable.

Among the above coating materials, yttrium hydroxide (Y (OH) ₃ ) and yttrium oxide (Y ₂ O ₃ ) are particularly preferable.

The said coating | coated substance may be used individually by the same covering element, and may use together 2 or more types from which it differs. For example, yttrium oxide and yttrium hydroxide may be used in combination as a coating substance containing Y.
Moreover, when using the coating material of a different coating element, each may be 1 type of coating material, and may use together 2 or more types of different coating materials. For example, when Y and La are included as the covering elements, a combination of yttrium oxide and lanthanum hydroxide may be used, or a combination of yttrium oxide and yttrium hydroxide and lanthanum hydroxide may be used.

Furthermore, the coating film formed on the phosphor by the coating substance may be one layer or two or more layers. In the case of two or more layers, different coating materials containing the same coating element may be used, and multilayers may be formed of coating materials containing different coating elements.
For example, the phosphor may be first coated with yttrium oxide and then further coated with lanthanum oxide.

In addition, the specific example of an above-described coating substance is not limited to these, As long as the effect of this invention is not impaired, you may use arbitrary combinations.
When two or more different coating materials are used, the mixing ratio is arbitrary as long as the effects of the present invention are not impaired.

The coating amount by the coating material is the weight of the coating element in terms of oxide, and usually 0.3 parts by weight or more and 5 parts by weight per 100 parts by weight of the phosphor before coating with the coating material (that is, the core phosphor described later). The lower limit is preferably 0.4 parts by weight, more preferably 0.5 parts by weight, and the upper limit is preferably 4 parts by weight, more preferably 3 parts by weight.
It is preferable that the coating amount by the coating substance is within the above range in that the luminous efficiency and luminescent color change over time when used in a light emitting device are reduced without reducing the luminous efficiency of the phosphor obtained.
Note that the coating amount by the coating substance can be calculated from the amount of the coating substance or the coating element compound used for the coating treatment of the core phosphor described later with the coating substance.

[Emission spectrum and excitation spectrum of phosphor]
<Excitation spectrum>
The emission peak of the excitation spectrum of the phosphor of the present invention is usually in the wavelength range of 200 nm or more, preferably 250 nm or more, more preferably 380 nm or more, and usually 430 nm or less, preferably 420 nm or less, more preferably 410 nm or less. .
That is, the phosphor of the present invention is usually excited by ultraviolet to violet light having a wavelength of 200 to 430 nm, preferably 380 to 430 nm, more preferably 380 to 420 nm, and most preferably 380 to 410 nm.
The emission peak wavelength of the excitation spectrum is usually 430 nm or less, preferably 350 nm or less.

<Excitation intensity ratio>
The phosphor of the present invention preferably satisfies the following formula (I) (hereinafter, the value calculated by the formula (I) may be referred to as “excitation intensity ratio”).
I ₄₃₀ / I ₃₈₀ ≧ 0.35 (I)
(In the above formula (I),
I ₄₃₀ represents emission intensity at an excitation wavelength of 430 nm in the excitation spectrum, and I ₃₈₀ represents emission intensity at an excitation wavelength of 380 nm in the excitation spectrum. )
The lower limit of formula (I) is preferably 0.37, more preferably 0.4.
It is preferable that the excitation intensity ratio calculated by the formula (I) is equal to or higher than the lower limit because high emission luminance can be obtained when excited by ultraviolet rays or violet light.
The upper limit of the excitation intensity ratio is not particularly limited, but is usually 1 because the phosphor is more easily excited by ultraviolet rays or violet light as the excitation intensity ratio is larger.

<Emission spectrum>
The phosphor of the present invention has an emission peak of an emission spectrum when excited with light having a wavelength of 405 nm, usually in a wavelength range of 420 nm or more, preferably 430 m or more, and preferably 500 nm or less, more preferably 490 nm or less. That is, the phosphor of the present invention has an emission color from blue to blue-green.

[Other properties and properties of phosphors]
<CIE chromaticity coordinates>
The x value of the CIE chromaticity coordinates of the phosphor of the present invention is usually 0.120 or more, preferably 0.130 or more, more preferably 0.140 or more, and usually 0.200 or less, preferably 0.180 or less. More preferably, it is 0.160 or less.
The y value of the CIE chromaticity coordinate of the phosphor of the present invention is usually 0.028 or more, preferably 0.07 or more, and usually 0.300 or less, preferably 0.250 or less.
Within the above range, when used in an image display device, the color reproduction range is widened, and when used in an illuminating device, color rendering properties are high.

<Particle size>
The weight median diameter (d ₅₀ ) of the phosphor of the present invention is usually in the range of 10 μm or more, particularly 11 μm or more, and usually 30 μm or less, especially 25 μm or less. When the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate. On the other hand, if the weight median diameter is too large, there is a tendency for coating unevenness and blockage of the dispenser to occur.
The weight median diameter (d ₅₀ ) of the phosphor can be measured using, for example, a laser diffraction / scattering particle size distribution measuring device.

[Phosphor production method]
In the phosphor of the present invention, the phosphor materials are mixed so that the composition of the formula [1] is obtained, the obtained phosphor material mixture is baked, and the phosphor before coating with the coating material (hereinafter, referred to as the phosphor material) May be referred to as a “core phosphor”), and the core phosphor may be coated with a coating material.

As the phosphor material, a metal compound, a metal, or the like is used.
For example, when producing a phosphor having the composition represented by the formula [1], a raw material of Sr element (hereinafter referred to as “Sr source” as appropriate), a raw material of Ba element (hereinafter referred to as “Ba source” as appropriate), P Element source (hereinafter referred to as “P source” where appropriate), O element source (hereinafter referred to as “O source” where appropriate), Cl element source (hereinafter referred to as “Cl source” where appropriate), Eu element source (hereinafter referred to as “Eu” where appropriate) The required combination is mixed (mixing step), the resulting mixture is fired (firing step), and the resulting fired product is dispersed, classified, and washed as necessary (post-processing step) ), And surface-treating (coating process) the obtained core phosphor with a coating material.
In the step of firing the phosphor raw material mixture, the alkaline earth metal (for example, Sr, Ba) and Cl are present in excess of the composition ratio of the formula [1] as will be described later, whereby the phosphor of the present invention. Is preferable in that it is easily obtained.

  Although an example of the manufacturing method of the fluorescent substance of this invention is shown below, this invention is not limited to these.

(Phosphor raw material)
As the phosphor material used in the method for producing the phosphor of the present invention, a known material can be used.

Specific examples of the Sr source include strontium oxide (SrO), strontium carbonate (SrCO ₃ ), strontium nitrate (Sr (NO ₃ ) ₂ ), strontium hydroxide (Sr (OH) ₂ ), and strontium oxalate (SrC ₂ O). ₄ ), strontium chloride (SrCl ₂ .6H ₂ O), strontium hydrogen phosphate (SrHPO ₄ ), strontium pyrophosphate (Sr ₂ P ₄ O ₇ ), strontium phosphate (Sr ₃ (PO ₄ ) ₂ ) and the like. It is done. Of these, strontium carbonate, strontium chloride, and strontium hydrogen phosphate are preferable.

Specific examples of the Ba source include barium oxide (BaO), barium hydroxide (Ba (OH) ₂ ), barium oxalate (BaC ₂ O ₄ ), barium chloride (BaCl ₂ ), and barium hydrogen phosphate (BaHPO ₄ ). , Barium nitrate (Ba (NO ₃ ) ₂ ), barium pyrophosphate (Ba ₂ P ₄ O ₇ ), barium phosphate (Ba ₃ (PO ₄ ) ₂ ), and the like. Of these, barium carbonate, barium chloride, and barium hydrogen phosphate are preferable.

Specific examples of the Eu source include europium oxide (Eu ₂ O ₃ ), europium hydroxide (Eu (OH) ₃ ), europium oxalate (Eu ₂ (C ₂ O ₄ ) ₃ ), europium chloride (EuCl ₃ ), And europium phosphate (EuPO ₄ ). Among these, europium oxide is preferable.

  That is, any of these carbonates, hydroxides, metals, chlorides, phosphates, and the like that can be converted into oxides, chlorides, and phosphates after heat treatment can be used as a raw material.

Specific examples of the P source include ammonium hydrogen phosphate ((NH ₄ ) ₂ HPO ₄ , (NH ₄ ) H ₂ PO ₄ ), diphosphorus pentoxide (P ₂ O ₅ ), and strontium hydrogen phosphate (SrHPO ₄ ), Barium hydrogen phosphate (BaHPO ₄ ), europium phosphate (EuPO ₄ ), strontium phosphate (Sr ₃ (PO ₄ ) ₂ ), strontium pyrophosphate (Sr ₂ P ₄ O ₇ ), barium phosphate (Ba ₃₎ (PO ₄ ) ₂ ), Sr sources such as barium pyrophosphate (Ba ₂ P ₄ O ₇ ), Ba sources, Eu source phosphates, and the like. Of these, strontium hydrogen phosphate is preferred.

Specific examples of the Cl source include Sr sources such as ammonium chloride (NH ₄ Cl), strontium chloride (SrCl ₂ .6H ₂ O), barium chloride (BaCl ₂ ), europium chloride (EuCl ₃ ), Ba source, Eu Source chlorides are listed. Of these, strontium chloride and barium chloride are preferred.

  Note that the O source (oxygen) in the formula [1] may be supplied from a Sr source, a Ba source, a Eu source, a P source, and a Cl source, or may be supplied from a firing atmosphere. Each raw material may contain inevitable impurities.

<Mixing process>
When producing the phosphor of the present invention, the phosphor raw materials are usually weighed so as to obtain the target composition and sufficiently mixed using a ball mill or the like to obtain a phosphor raw material mixture (mixing step).

Although it does not specifically limit as said mixing method, Specifically, the method of following (A) and (B) is mentioned.
(A) Dry pulverizer such as hammer mill, roll mill, ball mill, jet mill, etc., or pulverization using mortar and pestle, and mixer such as ribbon blender, V-type blender, Henschel mixer, or mortar and pestle And a dry mixing method in which the above phosphor raw materials are pulverized and mixed.
(B) A solvent or dispersion medium such as water is added to the phosphor material described above, and mixed using, for example, a pulverizer, a mortar and a pestle, or an evaporating dish and a stirring rod, to obtain a solution or slurry. A wet mixing method in which drying is performed by spray drying, heat drying, or natural drying.

  The mixing of the phosphor raw material may be either the wet mixing method or the dry mixing method, but in order to avoid contamination of the phosphor raw material with moisture, a dry mixing method or a wet mixing method using a water-insoluble solvent is more preferable. .

<Flux addition>
When producing the phosphor of the present invention, it is preferable that an alkaline earth metal compound (for example, Sr, Ba carbonate) and a chlorine compound are present in the step of firing the phosphor raw material. Here, the alkaline earth metal compound and the chlorine compound used are used as a flux (growth aid), and therefore the alkaline earth metal element and the chlorine element are present in excess of the composition ratio of the formula [1]. become.
Therefore, the alkaline earth metal compound and the chlorine compound in the present invention are not particularly limited as long as they have an effect as a flux, and may be either an organic substance or an inorganic substance, but preferably an alkaline earth metal chloride at the time of firing. Substances that change to the form are preferred.

As such, alkaline earth metal chlorides are preferable, and specifically, strontium chloride (SrCl ₂ .6H ₂ O) and barium chloride (BaCl ₂ ) are preferable. A mixture of ammonium chloride (NH ₄ Cl), strontium carbonate (SrCO ₃ ), barium carbonate (BaCO ₃ ), and the like are particularly preferable.

The above-mentioned alkaline earth metal compound and chlorine compound may be used alone or in combination of two or more different types.
These may be in the form of hydrates.

The amount of the flux used in the production method of the present invention is 1 part by weight or more and 50 parts by weight or less, more preferably 5 parts by weight or more and 30 parts by weight or less with respect to 100 parts by weight of the phosphor raw material. .
Furthermore, the use ratio of the alkaline earth metal compound and the chlorine compound added excessively as a flux is determined based on the total alkali with respect to the elemental amount (molar amount) of the total chlorine contained in the alkaline earth compound and chlorine compound added excessively as a flux. The ratio of earth metal element amount (molar amount) (alkaline earth metal element / chlorine element) is usually 1.5 or more, preferably 1.8 or more, and usually 2.5 or less, preferably 2.2 or less. is there.
Within the above range, the phosphor of the present invention can be easily obtained, which is preferable in terms of high emission luminance.

  The flux containing the alkaline earth metal compound and the chlorine compound only needs to be present when the phosphor raw material is fired, and the addition time and method are not particularly limited as long as the effects of the present invention are not impaired. From the viewpoint of easily obtaining the effects of the present invention, it is preferable to sufficiently mix the phosphor raw material before firing using a ball mill or the like.

  The mixing method is not particularly limited, and specifically, it is the same as the mixing of the phosphor raw materials, and includes the methods (A) and (B). Further, a flux may be added and mixed when the phosphor raw materials are mixed.

<Baking process>
What is necessary is just to set the calcination temperature of a fluorescent substance raw material mixture suitably with a composition in the temperature range of 800 to 1500 degreeC normally. The firing temperature is preferably 850 ° C. or higher, and preferably 1400 ° C. or lower.
The firing atmosphere in the firing step is arbitrary as long as the phosphor of the present invention can be obtained, but is usually a neutral to reducing atmosphere. Specific examples include a nitrogen gas atmosphere and a hydrogen gas-containing nitrogen gas atmosphere. Among them, a hydrogen gas-containing nitrogen gas atmosphere is preferable. The hydrogen gas content in the hydrogen gas-containing nitrogen gas atmosphere may be appropriately set depending on the composition in a concentration range of usually 1% by volume or more and 10% by volume or less. The hydrogen gas content is preferably 3% by volume or more, and preferably 8% by volume or less.
Note that the oxygen gas content in the firing atmosphere is controlled by the dew point of the gas to be supplied, and is usually 30 ° C. or lower, preferably 10 ° C. or lower.

  The temperature rising rate during firing is usually 2 ° C./min or more, preferably 3 ° C./min or more, and usually 20 ° C./min or less, preferably 15 ° C./min or less. If the rate of temperature rise is below this range, the firing time may be long. In addition, if the rate of temperature rise exceeds this range, the firing device, container, etc. may be damaged.

  The firing time varies depending on the firing temperature, atmosphere, and the like, but is usually 10 minutes or longer, preferably 1 hour or longer, and usually 48 hours or shorter, preferably 36 hours or shorter, particularly preferably 24 hours or shorter.

  Further, the phosphor obtained in the firing step may be further heat-treated at a temperature lower than the firing temperature in order to remove crystal defects and impurities generated in the crystal during firing or to thermally decompose unstable phases.

<Post-processing process>
(Washing process)
It is preferable to have a step (cleaning step) of washing the fired product after the step of firing the phosphor raw material mixture.
In particular, when the alkaline earth metal compound and the chlorine compound are used in excess of the composition ratio of the above formula [1] as the flux when the phosphor of the present invention is used, the firing residue of the flux is mainly contained in the fired product. There is a tendency that unreacted components of impurities and raw materials remain in the phosphor, and side reactions and the like are generated in the phosphor.
In order to improve the characteristics, it is necessary to remove the residual flux and raw material and impurities generated during firing as much as possible.

  The method for cleaning the fired product is not particularly limited as long as impurities can be removed. For cleaning, for example, hydrochloric acid, nitric acid, sodium hydroxide aqueous solution, or warm water can be used. However, the phosphor of the present invention is soluble in acid, and flux and generated impurities are easily dissolved in water. In view of solubility, it is preferable to wash with water, preferably pure water.

The pH of water used for washing (hereinafter sometimes referred to as “washing water”) is usually 4 or more, preferably 4.5 or more, more preferably 5.2 or more, and usually 10 or less. , Preferably 9 or less.
Within the above range, the flux in the phosphor, the residual material, and the impurities generated during firing can be efficiently removed.

The weight of the washing water when the phosphor is washed depends on the pH of the washing water to be used, but it is usually 1 or more times, usually 3 times or more, preferably 5 times or more, and usually 100 times or less, preferably 100 times or less. 50 times or less.
Here, the washing operation includes a method of washing the phosphor by immersing it in the washing water described above, but it may be left standing during the immersion, but the washing time is shortened from the viewpoint of work efficiency. It is preferable to stir to such an extent that it can be performed. In general, the operation is performed at room temperature (about 25 ° C.), but it is more preferable to heat the cleaning water as necessary because the solubility of impurities becomes high and the cleaning time and frequency can be reduced.
In the washing step, it is preferable to perform filtration after the work of immersing the phosphor in washing water for washing.

<Dispersing process>
The obtained fired product is granular or massive. This is dispersed to a predetermined particle size using a general disperser such as a ball mill, a vibration mill, or a jet mill. Selection of the disperser is selected according to the hardness of the fired product, but it is preferable to use a water dispersion ball mill from the strength of dispersion, and the ball used as the dispersion medium is made of a material that does not color the phosphor such as alumina or zirconia. It is more preferable to select.

A method suitable for the disperser to be used is selected as to whether the dispersion is performed by dispersion using a solvent (wet dispersion) or dry. If the intensity of dispersion is increased too much or the operation time of the disperser is increased too much, not only the fired product will be excessively crushed and fine particles that easily scatter light will be generated, but also crystal defects will be generated on the particle surface and light emission will occur. It can cause a decrease in efficiency.
The fired product is more preferably passed through a sieve before being dispersed so that the particle diameters are made uniform, so that a decrease in luminous efficiency after dispersion can be suppressed.
The baked product may be subjected to a sieve classification process with an opening of about 48 μm without passing through the dispersion process, and the powder that has passed through the sieve may be subjected to the next process.

<Classification process>
The fired product obtained in the firing step may be combined with a ball mill or the like and classified with a sieve having a mesh size of 15 to 60 μm, and classified with a water tank, if necessary, to combine coarse particles and fine particles. Adjust to particle size and particle size distribution. The phosphor is preferably treated so that its weight median diameter d ₅₀ is 30 μm or less, particularly 10 to 30 μm.

  Through the above steps, a core phosphor that is subjected to a coating treatment with a coating substance can be obtained.

<Coating process>
In the production of the phosphor of the present invention, the core phosphor obtained through the above-described steps is coated with the above-described coating substance.

Although the coating method is not particularly limited, the following methods (i) to (iii) are preferable.
In the following (i) to (iii), water is preferable as the solvent used for preparing the slurry, but an alcohol such as ethanol or an organic solvent such as acetone may be used.
(i) A phosphor (that is, a core phosphor) and a predetermined amount of a fine powder of a coating material are mixed in a solvent to form a phosphor slurry, and this slurry is thoroughly mixed and then dehydrated and dried.
(ii) A solution containing a covering element ion capable of forming a coating substance by a chemical reaction is put into a phosphor (ie, core phosphor) slurry, and mixed sufficiently, and then dehydrated and dried.
(iii) An aqueous solution of a covering element compound is put into a phosphor (ie, core phosphor) slurry and mixed sufficiently, and further, it is sufficiently reacted with the covering element ions to generate a covering material. An aqueous solution containing a counter ion is added, and the pH of the slurry is adjusted as necessary to deposit and adhere the coating substance on the phosphor surface, followed by dehydration and drying.

In the above method (i), when a fine powder such as a metal hydroxide is used as the coating material, the particle size is submicron of 1 μm or less, and the core phosphor is peeled off. It is preferable from the viewpoints that it is easy to form a difficult coating layer and that the coating substance is easily attached uniformly to the core phosphor.
Specifically, the average particle diameter of the attached coating substance is preferably 1/10 or less with respect to the average particle diameter of the phosphor (here, the weight median diameter d ₅₀ ), and the lower limit is 1 / A range of 50 or more is preferable.

  The adhesion amount of the coating material is the same as the coating amount of the coating material described above.

  Further, as described above, the phosphor of the present invention may be coated in multiple layers with a coating material, or may be coated with a mixture of two or more coating materials. The method of coating in multiple layers and the method of mixed coating are not particularly limited as long as the effects of the present invention are not impaired, but preferably the same method as described above, specifically, a fine powder slurry of a coating material or a chemical reaction by a chemical reaction. And depositing and adhering to the phosphor.

In addition, the phosphor of the present invention which is “layer-coated” can be manufactured by sequentially performing coating with two or more different coating substances. For example, after coating with the coating material A, coating with the coating material B results in a layered coating.
In addition, the phosphor of the present invention that has been “mixed coated” can be produced by simultaneously depositing two or more different coating substances. For example, when the coating material A and the coating material B are attached simultaneously, a mixed coating is obtained.
Further, by combining these adhesion methods, a phosphor in which “layer coating” and “mixed coating” are combined can be manufactured.

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

<Phosphor>
There is no restriction | limiting in the kind of fluorescent substance of this invention contained in the said fluorescent substance containing composition, It can select arbitrarily. Moreover, the fluorescent substance of this invention contained in a fluorescent substance containing composition may be only 1 type, and may use 2 or more types together by arbitrary combinations and a ratio. Furthermore, the phosphor-containing composition may contain a phosphor other than the phosphor of the present invention as long as the effects of the present invention are not significantly impaired.

<Liquid medium>
The liquid medium used in the phosphor-containing composition of the present invention is not particularly limited as long as the performance of the phosphor is not impaired within the intended range. For example, any inorganic material and / or organic material may be used as long as it exhibits liquid properties under the desired use conditions, suitably disperses the phosphor of the present invention, and does not cause an undesirable reaction. it can.
Specific examples of these inorganic materials and organic materials include those described in the section [Phosphor-containing composition] <Liquid medium> in JP-A-2007-291352.
In addition, the aspect of the said gazette is mentioned also about the content rate of a liquid medium and fluorescent substance.

[Light emitting device]
The light-emitting device of the present invention (hereinafter referred to as “light-emitting device” as appropriate) includes a semiconductor light-emitting element that emits light in the wavelength region of 380 nm to 430 nm and the phosphor of the present invention, and light emitted from the semiconductor light-emitting element. Is a phosphor conversion type light emitting device that generates light by converting the wavelength of the phosphor with the phosphor. More specifically, the first light emitter (excitation light source) emits light in the wavelength range of 380 to 430 nm. A semiconductor light-emitting element having a peak; and a second light-emitting body that emits visible light when irradiated with light from the first light-emitting body. The second light-emitting body includes at least one phosphor of the present invention. Is contained as the first phosphor. Here, any one of the phosphors of the present invention may be used alone, or two or more thereof may be used in any combination and ratio.

  As the phosphor of the present invention used as the first phosphor of the first light emitter, for example, a phosphor that emits blue to blue-green fluorescence under irradiation of light from an excitation light source is used. As the phosphor that emits fluorescence in the blue to blue-green region, a phosphor having a light emission peak in a wavelength range of 420 nm to 500 nm is preferable.

In this case, the light-emitting device of the present invention can be set, for example, in the following mode (a) or (b).
(A) A semiconductor light emitting element having a light emission peak in a wavelength range of 380 nm to 430 nm is used as the first light emitter, and light is emitted in a wavelength range of 530 nm to 620 nm as the second phosphor of the second light emitter. At least one phosphor having a peak is used.
(B) A semiconductor light emitting device having a light emission peak in the wavelength range of 380 nm to 430 nm is used as the first light emitter, and light is emitted in a wavelength range of 500 nm to 580 nm as the second phosphor of the second light emitter. At least one phosphor having a peak and at least one phosphor having an emission peak in a wavelength range of 570 nm to 780 nm are used.

  By using the phosphor of the present invention, the light emitting device of the present invention has an excitation light source (first light emitter) that emits light in the ultraviolet to violet region, that is, has a light emission peak in the wavelength range of 380 to 430 nm. It exhibits high light emission efficiency and high durability with respect to semiconductor light emitting elements, and is an excellent light emitting device when used in white light emitting devices such as lighting devices and light sources for liquid crystal displays.

  In addition, preferred specific examples of the phosphor of the present invention used in the light emitting device of the present invention include the phosphor of the present invention exemplified in the section of the phosphor of the present invention described above, and the column of [Example] described later. The phosphor used for each Example is mentioned.

  The light emitting device of the present invention has a semiconductor light emitting element having a light emission peak in the wavelength range of 380 to 430 nm as a first light emitter (excitation light source), and at least the phosphor of the present invention as a second light emitter. Other than using, the configuration is not limited, and a known device configuration can be arbitrarily adopted. A specific example of the device configuration will be described later.

  In the emission spectrum of the light emitting device of the present invention, the emission peak in the yellow region preferably has an emission peak in the wavelength range of 530 nm to 620 nm, and the emission peak in the orange to red region emits light in the wavelength range of 570 nm to 780 nm. Those having a peak are preferable, those having an emission peak in the wavelength range of 420 nm to 500 nm are preferable as the emission peak in the blue region, and those having an emission peak in the wavelength range of 500 nm to 580 nm as the emission peak in the green region Is preferred.

  Note that the emission spectrum of the light emitting device is measured by energizing 20 mA with a color / illuminance measurement software and USB2000 series spectroscope (integral sphere specification) manufactured by Ocean Optics in a room maintained at a temperature of 25 ± 1 ° C. Can be done. Chromaticity values (x, y, z) can be calculated as chromaticity coordinates in the XYZ color system defined by JIS Z8701 from data in the wavelength region of 380 nm to 780 nm of the emission spectrum. In this case, the relational expression x + y + z = 1 holds. In the present specification, the XYZ color system may be referred to as an XY color system, and is usually expressed as (x, y).

  The luminous efficiency is obtained by obtaining the total luminous flux from the result of the emission spectrum measurement using the light emitting device as described above, and dividing the lumen (lm) value by the power consumption (W). The power consumption is obtained by measuring a voltage using a True RMS Multimeters Model 187 & 189 manufactured by Fluke in a state in which 20 mA is energized, and obtaining the product of the current value and the voltage value.

  Among the light-emitting devices of the present invention, particularly as a white light-emitting device, specifically, a semiconductor light-emitting element having an emission peak in a wavelength range of 380 to 430 nm is used as an excitation light source of the first light emitter, as described above. In addition to the phosphor of the present invention, a phosphor emitting red fluorescence as will be described later (hereinafter referred to as “red phosphor” as appropriate), a phosphor emitting blue fluorescence (hereinafter referred to as “blue phosphor” as appropriate), A known phosphor such as a phosphor emitting green fluorescence (hereinafter referred to as “green phosphor” as appropriate) and a phosphor emitting yellow fluorescence (hereinafter referred to as “yellow phosphor” as appropriate) may be used in any combination. It can be obtained by taking a known device configuration.

  Here, the white color of the white light emitting device means all of (yellowish) white, (greenish) white, (blueish) white, (purple) white and white defined by JIS Z 8701 Of these, white is preferred.

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

The light emission wavelength of the first light emitter is not particularly limited as long as it overlaps with the absorption wavelength of the second light emitter described later, and a light emitter having a wide light emission wavelength region can be used. Usually, a light emitter having an emission wavelength from the ultraviolet region to the blue region is used, and it is particularly preferable to use a light emitter having an emission wavelength from the near ultraviolet region to the purple region.
As a specific numerical value of the emission peak wavelength of the first illuminant, 200 nm or more is usually desirable. Among these, when using near-ultraviolet light as excitation light, it is desirable to use a light emitter having an emission peak wavelength of usually 300 nm or more, preferably 330 nm or more, more preferably 360 nm or more, and usually 430 nm or less. This is from the viewpoint of color purity of the light emitting device.
In the present invention, a semiconductor light emitting device having a light emission peak in the wavelength range of 380 to 430 nm is used as the first light emitter, and specifically, a light emitting LED or a semiconductor laser diode (hereinafter referred to as “LD”). Or the like.) Or the like can be used.
Among these, as the first light emitter, a GaN LED or LD using a GaN compound semiconductor is preferable. This is because GaN-based LEDs and LDs have significantly higher light output and external quantum efficiency than SiC-based LEDs that emit light in this region, and are extremely low power and extremely low power when combined with the phosphor of the present invention. This is because bright light emission can be obtained. For example, for a current load of 20 mA, GaN LEDs and LDs usually have a light emission peak intensity that is 100 times or more that of SiC. In GaN-based LEDs and LDs, an Al _x Ga _y N light emitting layer (where x and y represent the composition ratio of Al and Ga), a GaN light emitting layer or an In _w Ga _z N light emitting layer (where w, It is preferable that z represents a composition ratio of In and Ga. Among GaN-based LEDs, those having an In _x Ga _y N light-emitting layer are particularly preferable because the emission peak intensity is very strong, and in GaN-based LEDs, multiple quantum wells of In _x Ga _y N layer and GaN layer are used. The structure is particularly preferable because the emission peak intensity is very strong.

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

A GaN-based LED has these light emitting layer, p layer, n layer, electrode, and substrate as basic components, and the light emitting layer is made of n-type and p-type Al _x Ga _y N layers, GaN layers, or In _x. Those having a hetero structure sandwiched by Ga _y N layers or the like are preferable because of high light emission efficiency, and those having a hetero structure having a quantum well structure are more preferable because of high light emission efficiency.

  Note that only one first light emitter may be used, or two or more first light emitters may be used in any combination and ratio.

<Second luminous body>
The second light emitter in the light emitting device of the present invention is a light emitter that emits visible light when irradiated with light from the first light emitter described above, and contains the phosphor of the present invention described above as the first phosphor. In addition, a second fluorescent material (a red fluorescent material, a blue fluorescent material, a green fluorescent material, an orange fluorescent material, a yellow fluorescent material, etc.), which will be described later, is appropriately contained depending on the application. Here, the phosphor of the present invention is only required to satisfy the composition, physical properties and characteristics unique to the phosphor of the present invention, and the emission color is not particularly limited. Further, for example, the second light emitter is configured by dispersing the first and second phosphors in a sealing material.

The composition of the phosphor other than the phosphor of the present invention used in the second light emitter is not particularly limited, and examples thereof include Y ₂ O ₃ , YVO ₄ , and Zn that become a crystal matrix. ₂ SiO ₄ , Y ₃ Al ₅ O ₁₂ , metal oxides typified by Sr ₂ SiO ₄ , metal nitrides typified by Sr ₂ Si ₅ N ₈ , Ca ₁₀ (PO ₄ ) ₆ Cl _2, etc. Ce, Pr, Nd, Pm, Sm, such as phosphates represented by ZnS, SrS, CaS and the like, oxysulfides represented by Y ₂ O ₂ S, La ₂ O ₂ S, etc. , Eu, Tb, Dy, Ho, Er, Tm, Yb or other rare earth metal ions, or Ag, Cu, Au, Al, Mn, Sb or other metal ions combined as an activator or coactivator Is mentioned.

(First phosphor)
The second light emitter in the light emitting device of the present invention contains at least the above-described phosphor of the present invention as the first phosphor. Any one of the phosphors of the present invention may be used alone, or two or more thereof may be used in any combination and ratio. In addition to the phosphor of the present invention, a phosphor that emits fluorescence of the same color as the phosphor of the present invention (same color combined phosphor) may be used as the first phosphor. For example, when the phosphor of the present invention is a blue phosphor, another type of blue phosphor can be used in combination with the phosphor of the present invention as the first phosphor.

Other types of blue phosphors include europium activated alkaline earth magnesium aluminate phosphors represented by (Ba, Sr, Ca) MgAl ₁₀ O ₁₇ : Eu, (Mg, Ca, Sr, Ba) ₁₀ (PO ₄ ) ₆ (Cl, F) ₂ : Europium-activated alkaline earth halophosphate phosphor represented by Eu, (Ca, Sr, Ba) ₂ B ₅ O ₉ Cl: Europium-activated alkali represented by Eu Europium activated alkaline earth aluminate phosphor represented by earth chloroborate phosphor, (Sr, Ca, Ba) Al ₂ O ₄ : Eu or (Sr, Ca, Ba) ₄ Al ₁₄ O ₂₅ : Eu 1 type, or 2 or more types of blue fluorescent substance chosen from the group which consists of etc. is preferable.

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

  The weight median diameter of the second phosphor used in the light emitting device of the present invention is usually in the range of 10 μm or more, especially 12 μm or more, and usually 30 μm or less, especially 25 μm or less. When the weight median diameter is too small, the luminance is lowered and the phosphor particles tend to aggregate. On the other hand, if the weight median diameter is too large, there is a tendency for coating unevenness and blockage of the dispenser to occur.

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

Examples of such orange to red phosphors are (Ca, Sr) AlSiN ₃ : Eu, (Mg, Ca, Sr, Ba) ₂ Si ₅ N ₈ : Eu, and SrAlSi ₄ N ₇ : Eu. Examples include europium-activated alkaline earth silicon nitride phosphors, europium-activated rare earth oxychalcogenide phosphors represented by (Y, La, Gd, Lu) ₂ O ₂ S: Eu that emit light in the red region.
Any one of these orange to red phosphors may be used alone, or two or more thereof may be used in any combination and ratio.

<Green phosphor>
When a green phosphor is used as the second phosphor, any green phosphor can be used as long as the effects of the present invention are not significantly impaired. At this time, the emission peak wavelength of the green phosphor is usually 500 nm or more, preferably 505 nm or more, more preferably 510 nm or more, and usually 580 nm or less, preferably 570 nm or less, more preferably 560 nm or less, still more preferably 550 nm or less. It is preferable to be in the wavelength range.
As such a green phosphor, (Lu, Y, La, Gd) ₃ (Al, Ga) ₅ O ₁₂ : Ce, (Ba, Sr) ₃ Si ₆ O ₁₂ N ₂ : Eu, (Ba, Sr) ₂ SiO ₄ : Eu, Ca ₃ Sc ₂ Si ₃ O ₁₂ : Ce, CaSc ₂ O ₄ : Ce, (Ca, Sr) ₈ (Mg, Zn) (SiO ₄ ) ₄ Cl ₂ : Eu, (Sr, Ca, Ba) (Al, Ga, In) ₂ S ₄ : Eu, (Mg, Ca, Sr, Ba) Si ₂ O ₂ N ₂ : Eu, and β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu Etc.
One of these green phosphors may be used alone, or two or more thereof may be used in any combination and ratio.

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

Examples of such yellow phosphors include various oxide-based, nitride-based, oxynitride-based, sulfide-based, and oxysulfide-based phosphors.
In particular, RE ₃ M ₅ O ₁₂ : Ce (where RE represents at least one element selected from the group consisting of Y, Tb, Gd, Lu, La, and Sm, and M represents Al, Ga, and And a garnet-based phosphor having a garnet structure represented by the formula (1) representing at least one element selected from the group consisting of Sc.

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

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

  In the light emitting device of the present invention, the presence / absence and type of the second phosphor (orange to red phosphor, yellow phosphor, etc.) described above may be appropriately selected according to the use of the light emitting device.

  On the other hand, when the light-emitting device of the present invention is configured as a light-emitting device that emits white light, the first light-emitting body, the first phosphor (the phosphor of the present invention), and the like so as to obtain desired white light. What is necessary is just to combine a 2nd fluorescent substance appropriately.

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

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

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

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

The liquid medium may further contain known additives such as a diffusing agent, a filler, a viscosity modifier, and an ultraviolet absorber.
In addition, these additives may use only 1 type and may use 2 or more types together by arbitrary combinations and ratios.

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

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

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

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

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

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

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

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

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

  FIG. 3 is a cross-sectional view schematically showing one embodiment of the illumination device of the present invention. As shown in FIG. 3, the surface-emitting illumination device 11 has a large number of light-emitting devices 13 (the light-emitting device 4 described above) on the bottom surface of a rectangular holding case 12 whose inner surface is light-opaque such as a white smooth surface. Is provided with a power supply and a circuit (not shown) for driving the light-emitting device 13 on the outside, and a milky white acrylic plate or the like is provided at a position corresponding to the lid portion of the holding case 12. The diffusion plate 14 is fixed for uniform light emission.

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

[Liquid Crystal Display]
When the light emitting device of the present invention is used as a light source of a liquid crystal display device using a color liquid crystal display element, the specific configuration of the liquid crystal display device is not limited, but is preferably used with a color filter. For example, in the case of a color liquid crystal display device, a liquid crystal display device can be formed by combining the light emitting device using a liquid crystal and an optical shutter using liquid crystal and a color filter having red, green, and blue pixels. it can.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further more concretely, this invention is not limited to a following example, unless the summary is exceeded.

[Measurement method of excitation spectrum and emission spectrum]
The excitation spectrum and emission spectrum were measured with a fluorescence spectrophotometer FP6500 (manufactured by JASCO Corporation).
The emission spectrum was measured by excitation with purple light (purple LED) having a peak wavelength of 405 nm, and the peak wavelength was determined.
In addition, the peak wavelength in the excitation spectrum was confirmed, and the emission intensity ratios I ₄₃₀ / I ₃₈₀ were calculated with the emission intensities at the excitation wavelengths of 430 nm and 380 nm being I ₄₃₀ and I ₃₈₀ , respectively.

[Measurement method of luminance and chromaticity]
The chromaticity coordinates of the x, y color system (CIE 1931 color system) are defined by JIS Z8701 in accordance with JIS Z8724 from the emission spectrum of excitation light having a peak wavelength of 405 nm obtained by the above method. The chromaticity coordinates x and y in the XYZ color system are calculated. The luminance was expressed as a relative value when the Y value in the XYZ color system of the phosphor of Comparative Example 1 was set to 100 in the emission spectrum.

[Measurement method of weight-average median diameter _{d 50]}
And weighed median size d ₅₀ of the phosphor by using a laser diffraction / scattering particle size distribution measuring apparatus.

[Evaluation method of luminous flux maintenance factor of white LED]
A current of 20 mA was applied to the manufactured white LED to light continuously for 1000 hours, the light flux after lighting for 1000 hours was measured, and the ratio of the light flux to the light flux immediately after lighting (light flux maintenance factor) was calculated by the following formula. .
Luminous flux maintenance factor = (luminous flux after 1000 hours lighting / luminous flux immediately after lighting) × 100

[Example 1]
<Synthesis of phosphor>
(Phosphor raw material)
SrHPO ₄ : 1.5553 mol
Eu ₂ O ₃ : 0.1288 mol
SrCO ₃ : 0.2472 mol
BaCO ₃ : 0.2575 mol
SrCl ₂ · 6H ₂ O: 0.2575 mol
BaCl ₂ : 0.2575 mol
A phosphor raw material mixture obtained by sufficiently mixing the above raw materials as a phosphor raw material is filled in a crucible, covered, and dried in a nitrogen gas atmosphere containing hydrogen gas at a maximum temperature of 965 ° C. And baked for 12 hours.
Next, the fired powder is dispersed, washed with pure water, dried, and subjected to a sieving process, and the composition formula is represented by (Sr _0.8 Ba _0.1 Eu _0.1 ) ₁₀ (PO ₄ ) ₆ Cl _2. Eu ²⁺ activated strontium barium chlorophosphate phosphor (hereinafter referred to as “core phosphor 1”) was obtained.

  Next, 0.01 g of oxalic acid was added to 400 ml of pure water and stirred sufficiently, and then 28 wt% aqueous ammonia was added to adjust the pH to 9. 100 g of core phosphor 1 was added to an ammonium oxalate aqueous solution adjusted to pH 9 to prepare a slurry of core phosphor 1 (hereinafter referred to as “core phosphor slurry 1”).

Separately from the core phosphor slurry 1, 1 g of yttrium oxide was dispersed in 150 ml of pure water, and 3.3 ml of 69% by weight nitric acid was added to prepare an acidic aqueous solution of yttrium nitrate. To this aqueous yttrium nitrate solution, 6.7 ml of 28 wt% aqueous ammonia was added dropwise to adjust the pH to 9 to prepare 160 ml of yttrium hydroxide slurry.
Next, the whole amount (160 ml) of the yttrium hydroxide slurry is added to the core phosphor slurry 1, and the slurry is sufficiently stirred and then left to stand to remove the supernatant, rinse with water, and then dehydrate. The Eu2 ⁺ -activated strontium barium chlorophosphate phosphor of Example 1 in which 1 part by weight of an yttrium compound in terms of yttrium oxide was adhered to the surface with respect to 100 parts by weight of the core phosphor 1 was obtained.

When the phosphor of Example 1 is irradiated with violet light having a wavelength of 405 nm, the peak wavelength of the emission spectrum is 454 nm, and the emission chromaticity (x, y) by the CIE color system is x = 0.146, y = 0. 141 and was a practical emission color as a blue-emitting phosphor.
The peak wavelength of the excitation spectrum of the phosphor of Example 1 was 350 nm or less, and the excitation intensity ratio (I ₄₃₀ / I ₃₈₀ ) was about 0.60.
When the emission luminance when the phosphor of this Example 1 was irradiated with violet light having a wavelength of 405 nm was measured, the relative luminance was 194.
The weight median size _{d 50} of the phosphor of Example 1 was 11.3Myuemu.

<Manufacture of white LED>
Using the phosphor of Example 1 as a blue phosphor, Eu ²⁺ activated alkaline earth silicon nitride phosphor ((Ca, Sr) AlSiN ₃ : Eu) (red phosphor) and Eu ²⁺ activated aluminosilicon oxy A mixture obtained by mixing a nitride-based phosphor (β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu) (green phosphor) at a predetermined mixing ratio is a silicone resin ND113D (manufactured by Mitsubishi Chemical Corporation). A phosphor-containing composition was prepared by adding and dispersing 10 parts by weight with respect to 100 parts by weight.
The blue phosphor, the (Ca, Sr) AlSiN ₃ : Eu red phosphor, and the β- (Si, Al) ₁₂ (O, N) ₁₆ : Eu green phosphor of Example 1 are emitted from the obtained white LED. The mixing ratio was adjusted so that the chromaticity (x, y) was x = 0.43 and y = 0.40.
One 350 μm square InGaN-based near-ultraviolet LED chip (emission peak wavelength 406 nm) was mounted on a 3528 SMD type PPA resin package, and sealed with this phosphor-containing composition to obtain a white LED of Example 1.
When the luminous flux maintenance factor of the white LED of Example 1 was determined, the luminous flux maintenance factor was 98%.

[Example 2]
100 g of the core phosphor 1 produced in the same manner as in Example 1 was put into 400 ml of pure water and sufficiently stirred to prepare a slurry (hereinafter referred to as “core phosphor slurry 2”).
Example in which 1% by weight of yttrium compound in terms of yttrium oxide was attached to the surface of the core phosphor 1 in the same manner as in Example 1 except that the core phosphor slurry 2 was used instead of the core phosphor slurry 1 2 Eu ²⁺ activated strontium barium chlorophosphate phosphors were obtained.

On this peak wavelength of the excitation spectrum of the phosphor of Example 2 is 350nm or less, the peak wavelength of the emission spectrum, the emission chromaticity by CIE color system (x, y), relative luminance, excitation intensity ratio, d ₅₀ Table As shown in FIG.
Next, the emission chromaticity (x, y) is x = 0.43 in the same manner as in Example 1 except that the phosphor of Example 2 is used instead of the phosphor of Example 1 as the blue phosphor. A white LED of Example 2 with y = 0.40 was manufactured.
The luminous flux maintenance factor of the white LED of Example 2 was as shown in Table 1.

[Example 3]
100 g of the core phosphor 1 produced in the same manner as in Example 1 and 2.0 g of ammonium hydrogen carbonate were put into 400 ml of pure water and sufficiently stirred to obtain a slurry (hereinafter referred to as “core phosphor slurry 3”). Was prepared.
Separately from the core phosphor slurry 3, 2 g of yttrium oxide was dispersed in 160 ml of pure water, and 3.3 ml of 69% by weight nitric acid was added to prepare an acidic aqueous solution of yttrium nitrate. To this aqueous yttrium nitrate solution, 6.7 ml of 28% ammonia water was added dropwise to adjust the pH to 9 to prepare 160 ml of yttrium hydroxide slurry.
Next, the total amount (160 ml) of the above yttrium hydroxide slurry is added to the core phosphor slurry 3, and the phosphor slurry is sufficiently stirred and then allowed to stand to remove the supernatant, washed with water, The Eu ²⁺ activated strontium barium chlorophosphate phosphor of Example 3 in which 1% by weight of an yttrium compound in terms of yttrium oxide was adhered to the surface of the core phosphor 1 was obtained by performing dehydration.

On this peak wavelength of the excitation spectrum of the phosphor of Example 3 is 350nm or less, the peak wavelength of the emission spectrum, the emission chromaticity by CIE color system (x, y), relative luminance, excitation intensity ratio, d ₅₀ Table As shown in FIG.
Next, the emission chromaticity (x, y) is x = 0.43 in the same manner as in Example 1 except that the phosphor of Example 3 is used instead of the phosphor of Example 1 as the blue phosphor. A white LED of Example 3 with y = 0.40 was manufactured.
The luminous flux maintenance factor of the white LED of Example 3 was as shown in Table 1.

[Example 4]
1 g of lanthanum oxide was dispersed in 150 ml of pure water, and 69% by weight of nitric acid was added until the lanthanum oxide was dissolved to prepare an acidic aqueous solution of lanthanum nitrate. A 28 wt% aqueous ammonia was dropped into this lanthanum nitrate aqueous solution so that the pH was 9 to prepare a lanthanum hydroxide slurry.
Next, the entire amount of the above lanthanum hydroxide slurry was added to the core phosphor slurry 2 prepared in the same manner as in Example 2, and the phosphor slurry was sufficiently stirred and allowed to stand. , Washed with water, dehydrated and dried, and Eu ²⁺ activated strontium barium chlorophosphate phosphor of Example 4 in which 1% by weight of lanthanum compound in terms of lanthanum oxide was attached to the surface of the core phosphor 1 Got.

On this peak wavelength of the excitation spectrum of the phosphor of Example 4 350nm or less, the peak wavelength of the emission spectrum, the emission chromaticity by CIE color system (x, y), relative luminance, excitation intensity ratio, d ₅₀ Table As shown in FIG.
Next, the emission chromaticity (x, y) is x = 0.43 in the same manner as in Example 1 except that the phosphor of Example 4 is used instead of the phosphor of Example 1 as the blue phosphor. A white LED of Example 4 with y = 0.40 was produced.
The luminous flux maintenance factor of the white LED of Example 4 was as shown in Table 1.

[Examples 5 to 19]
Eu ²⁺ -activated strontium barium chloro whose composition formula is shown in Table 1 except that the phosphor raw materials shown in Table 2 below were used in the proportions shown in Table 2 in the same manner as in Example 1. A phosphate phosphor was obtained.

Using each of the obtained phosphors as a core phosphor, a core phosphor slurry was prepared in the same manner as in Example 2, and the same operation as in Example 2 was performed. Each core phosphor was converted to 1 in terms of yttrium oxide. The Eu ²⁺ activated strontium barium chlorophosphate phosphors of Examples 5 to 19 having the weight% yttrium compound adhered to the surface were obtained.
The peak wavelengths of the excitation spectra of the phosphors of Examples 5 to 19 are 350 nm or less, the peak wavelength of the emission spectrum, the emission chromaticity (x, y) according to the CIE color system, the relative luminance, the excitation intensity ratio, d _50. Was as shown in Table 1.
Next, the emission chromaticity (x, y) is x = x in the same manner as in Example 1 except that the phosphors of Examples 5 to 19 are used instead of the phosphor of Example 1 as the blue phosphor. White LEDs of Examples 5 to 19 with 0.43 and y = 0.40 were manufactured.
The luminous flux maintenance factors of the white LEDs of Examples 5 to 19 were as shown in Table 1.

[Comparative Examples 1 to 10]
Eu ²⁺ -activated strontium barium calcium magnesium whose composition formula is shown in Table 1 in the same manner as in Example 1 except that the phosphor raw materials shown in Table 2 below were used in the proportions shown in Table 2. The phosphors of Comparative Examples 1 to 10 which were chlorophosphate phosphor, Eu ²⁺ activated strontium chlorophosphate phosphor, or Eu ²⁺ activated strontium barium chlorophosphate phosphor were obtained.

The peak wavelengths of the excitation spectra of the phosphors of Comparative Examples 1 to 10 are 350 nm or less, the peak wavelength of the emission spectrum, the emission chromaticity (x, y) according to the CIE color system, the relative luminance, the excitation intensity ratio, and d _50. Was as shown in Table 1.
Next, except that the phosphors of Comparative Examples 1 to 10 are used instead of the phosphor of Example 1 as the blue phosphor, the emission chromaticity (x, y) is x = White LEDs of Comparative Examples 1 to 10 having 0.43 and y = 0.40 were manufactured.
The luminous flux maintenance factors of the white LEDs of Comparative Examples 1 to 10 were as shown in Table 1.

From the above results, the following can be understood.
The excitation intensity ratio (I ₄₃₀ / I ₃₈₀ ) of the phosphor of Comparative Example 1 is 0.22, and the brightness of the powder is low when excited with ultraviolet light or purple light having a wavelength of 380 to 430 nm. When used together with the light conversion member, sufficient luminous efficiency cannot be obtained. A white LED using this phosphor had a luminous flux maintenance factor of 89% or less and a poor luminous flux maintenance factor.
The relative luminance of the phosphor of Comparative Example 2 corresponding to the core phosphor of Examples 1 to 4 was 192, but the luminous flux maintenance factor of the white LED using this phosphor was as bad as 86%.
The phosphors of Comparative Examples 3 to 10 are also practically luminescent colors as blue phosphors, but the excitation intensity ratio (I ₄₃₀ / I ₃₈₀ ) is less than 0.35 and is excited by ultraviolet rays or violet light having a wavelength of 380 nm to 430 nm. In this case, the brightness of the powder is low, and sufficient luminous efficiency cannot be obtained when used with a light conversion member such as an ultraviolet LED or a purple LED. Further, the luminous flux maintenance factor of white LEDs using these phosphors was 89% or less, and the luminous flux maintenance factor was poor.

On the other hand, the peak wavelength of the emission spectrum when the phosphors of Examples 1 to 4 were irradiated with purple light having a wavelength of 405 nm was 454 nm, and the emission chromaticity (x, y) by the CIE color system was x = 0. 146, y = 0.141, a practical emission color as a blue phosphor, the peak wavelength of the excitation spectrum is 350 nm or less, and the excitation intensity ratio (I ₄₃₀ / I ₃₈₀ ) is 0.60. Large and high relative luminance. Moreover, the luminous flux maintenance factor of the white LED using these phosphors was 96 to 98%, and the luminous flux maintenance factor was improved as compared with the white LED using the phosphor of Comparative Example 2.
The phosphors of Examples 5 to 19 are also practically luminescent colors as blue phosphors, and the excitation intensity ratio (I ₄₃₀ / I ₃₈₀ ) is 0.35 or more, and when excited with ultraviolet rays or violet light having a wavelength of 380 nm to 430 nm. The brightness of the powder is high, and when it is used together with a light conversion member such as an ultraviolet LED or a purple LED, the luminous efficiency is high. Further, the luminous flux maintenance factor of the white LED using these phosphors was 95% or more, and the luminous flux maintenance factor was improved as compared with the white LED of Comparative Example 2.

1 Phosphor-containing part (second light emitter)
2 Excitation light source (first light emitter) (LD)
3 Substrate 4 Light-emitting device 5 Mount lead 6 Inner lead 7 Excitation light source (first light emitter)
8 Phosphor-containing resin part 9 Conductive wire 10 Mold member 11 Surface emitting illumination device 12 Holding case 13 Light emitting device 22 Excitation light source (first light emitter)
23 Phosphor-containing part (second light emitter)
24 frame 25 conductive wire 26 electrode 27 electrode

Claims (10)

A phosphor represented by the following formula [1],
It is coated with a compound (hereinafter referred to as “coating element”) containing one or more elements selected from the group consisting of Y, La, Lu and Gd (hereinafter referred to as “coating element”). And a phosphor.
(Sr _a Ba _b Eu _c ) (PO ₄ ) ₆ Cl ₂ [1]
(In Formula [1], a, b, c, and d are values in the following ranges, respectively.
1 ≦ a ≦ 9.68
0.02 <b ≦ 3
0.3 ≦ c ≦ 2
a + b + c = 10)   The phosphor according to claim 1, wherein the coating substance is one or more selected from the group consisting of oxides, hydroxides, carbonates, and oxalates.   The phosphor according to claim 1, wherein the phosphor is coated with two or more kinds of the coating substances.   The amount of the coating material is 0.3 parts by weight or more and 5 parts by weight or less in terms of oxide of the coating element with respect to 100 parts by weight of the phosphor. The phosphor according to claim 1. The phosphor according to any one of claims 1 to 4, wherein the following formula (I) is satisfied.
I ₄₃₀ / I ₃₈₀ ≧ 0.35 (I)
(In the above formula (I),
I ₄₃₀ represents emission intensity at an excitation wavelength of 430 nm in the excitation spectrum, and I ₃₈₀ represents emission intensity at an excitation wavelength of 380 nm in the excitation spectrum. ) 6. The phosphor according to claim 1, wherein a weight median diameter (d ₅₀ ) is 10 μm or more and 30 μm or less.   A phosphor-containing composition comprising the phosphor according to any one of claims 1 to 6 and a liquid medium.   A phosphor conversion type light emitting device including a semiconductor light emitting element that emits light in a wavelength region of 380 nm to 430 nm and a phosphor, and generates light obtained by wavelength-converting light emitted from the semiconductor light emitting element with the phosphor. The light emitting device according to claim 1, wherein the phosphor is the phosphor according to claim 1.   An illumination device comprising the light emitting device according to claim 8 as a light source.   A liquid crystal display device comprising the light-emitting device according to claim 8 as a light source.

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