WO2018003605A1 - Process for producing red fluorescent substance - Google Patents
Process for producing red fluorescent substance Download PDFInfo
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- WO2018003605A1 WO2018003605A1 PCT/JP2017/022701 JP2017022701W WO2018003605A1 WO 2018003605 A1 WO2018003605 A1 WO 2018003605A1 JP 2017022701 W JP2017022701 W JP 2017022701W WO 2018003605 A1 WO2018003605 A1 WO 2018003605A1
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- strontium
- nitride
- raw material
- red phosphor
- phosphor
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- C—CHEMISTRY; METALLURGY
- C01—INORGANIC CHEMISTRY
- C01B—NON-METALLIC ELEMENTS; COMPOUNDS THEREOF; METALLOIDS OR COMPOUNDS THEREOF NOT COVERED BY SUBCLASS C01C
- C01B21/00—Nitrogen; Compounds thereof
- C01B21/082—Compounds containing nitrogen and non-metals and optionally metals
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
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- C—CHEMISTRY; METALLURGY
- C09—DYES; PAINTS; POLISHES; NATURAL RESINS; ADHESIVES; COMPOSITIONS NOT OTHERWISE PROVIDED FOR; APPLICATIONS OF MATERIALS NOT OTHERWISE PROVIDED FOR
- C09K—MATERIALS FOR MISCELLANEOUS APPLICATIONS, NOT PROVIDED FOR ELSEWHERE
- C09K11/00—Luminescent, e.g. electroluminescent, chemiluminescent materials
- C09K11/08—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials
- C09K11/64—Luminescent, e.g. electroluminescent, chemiluminescent materials containing inorganic luminescent materials containing aluminium
Definitions
- the present invention relates to a method for producing a red phosphor.
- the present invention generally provides a SCASN phosphor that absorbs light from a light emitting element such as an LED and emits red light, wherein the base crystal has substantially the same crystal structure as (Sr, Ca) AlSiN 3.
- the present invention relates to a method for manufacturing a phosphor called “a”.
- a white LED includes a semiconductor light-emitting element that is a light-emitting light source, and a phosphor that has a relatively high energy of the light-emitting light source and absorbs part of light with a short wavelength as excitation light and converts it to another color with a long wavelength. It is a device that emits pseudo white light by a combination, and a blue LED and a YAG (yttrium, aluminum, garnet) yellow phosphor are known as a typical example of the combination.
- Patent Document 1 proposes to use a nitride or oxynitride phosphor that emits red light together with a YAG phosphor in order to compensate for the insufficient red light-emitting component.
- Patent Document 2 describes that a phosphor having an emission peak wavelength shifted to the short wavelength side can be obtained by substituting part of Ca with Sr while maintaining the crystal phase.
- the phosphor is called, for example, a (Sr, Ca) AlSiN 3 phosphor activated by Eu 2+ , and tends to increase spectral components in a region having a shorter emission wavelength and higher visibility than the CaAlSiN 3 phosphor. Therefore, it is effective as a red phosphor for high brightness white LED.
- CaAlSiN 3 phosphor and (Sr, Ca) AlSiN 3 fluorescent material CaAlSiN 3 based nitride phosphor, such as, for containing many spectral components to long red region especially wavelengths in the red, while capable of realizing a high color rendering property
- CaAlSiN 3 based nitride phosphor such as, for containing many spectral components to long red region especially wavelengths in the red, while capable of realizing a high color rendering property
- the ratio of spectral components having low visibility is increased, and the luminance as a white LED generally tends to be low. Therefore, in order to provide a light emitting device with high light emission luminance in the industry, it has been expected to increase the luminance of the red phosphor.
- the main object of the present invention is to provide a method for producing a red phosphor having excellent luminance.
- the red phosphor for example (Sr, Ca) AlSiN 3
- strontium nitride having a specific value of less than a specific value is used as a raw material, it has been found that a red phosphor having high luminance can be produced, and the present invention has been completed.
- the present invention is as follows.
- the present invention is a method for producing a red phosphor containing strontium, which has a firing step of firing a raw material mixture containing strontium nitride using strontium nitride having a hydrogen content of 500 ppm or less as a raw material.
- the present invention uses strontium nitride having a hydrogen content of 500 ppm or less as a raw material, and includes a mixing step of mixing a plurality of raw materials, and a baking step of firing the raw material mixture after the mixing step, and a red color containing strontium It is a manufacturing method of fluorescent substance.
- luminance can be provided.
- a high red phosphor luminance for example (Sr, Ca) AlSiN 3 the same crystal phase as a host crystal phase, the red phosphor comprising strontium, it is possible to provide a manufacturing method.
- a high-luminance light emitting element can be provided by combining the red phosphor and a light emitting light source such as an LED. Note that the effects described here are not necessarily limited, and may be any of the effects described in the present specification.
- the main crystal phase of the red phosphor is, for example, the same crystal phase as (Sr, Ca) AlSiN 3 as a base crystal phase.
- the composition of the main crystal phase of the phosphor is represented by the general formula (Sr, Ca) AlSiN 3 , but the raw materials may be blended so as to obtain the phosphor having such a composition.
- the composition of the phosphor may fluctuate during firing.
- the composition of the red phosphor according to the present specification is an expression including such variation.
- the main crystal phase of the red phosphor is the same crystal phase as, for example, (Sr, Ca) AlSiN 3 can be confirmed by powder X-ray diffraction measurement.
- the main crystal phase for example (Sr, Ca) crystal structure of the red phosphor prepared to have the same crystalline phase and AlSiN 3 is (Sr, Ca) if different from the AlSiN 3, the light emitting color This is not preferable because it is no longer red or the fluorescence intensity is greatly reduced.
- the main crystal phase is preferably the same as the (Sr, Ca) AlSiN 3 and a single-phase crystal, but may contain a different phase as long as the phosphor characteristics are not greatly affected.
- the presence or absence of a heterogeneous phase can be determined by the presence or absence of a peak other than that due to the target crystal phase, for example, by powder X-ray diffraction.
- the crystal structure of, for example, (Sr, Ca) AlSiN 3 which is a red phosphor is a structure in which (Si, Al) -N4 tetrahedrons are bonded, and a crystal structure in which Sr atoms and Ca atoms are located in the gaps.
- (Sr, Ca) AlSiN 3 when a part of Sr 2+ or Ca 2+ located in the gap of the crystal structure is replaced with Eu 2+ acting as a luminescence center, a red phosphor called a so-called SCASN phosphor is obtained.
- the red phosphor of the present invention is a phosphor having the same crystal phase as, for example, (Sr, Ca) AlSiN 3 as a host crystal phase
- the rate is preferably 0.01 to 0.4 atomic%.
- a more preferable range of the Eu content in the raw material is 0.01 to 0.3 atom%, more preferably 0.04 to 0.2 atom%, and still more preferably 0.06 to 0.15 atom. %.
- the phosphor obtained by the manufacturing method of the present embodiment contains a trace amount of oxygen (O) as an inevitable component. Then, the occupancy ratio of Ca and Sr, the Si / Al ratio, and the N / O ratio, which are the composition parameters of the phosphor, are adjusted so that the electrical neutrality is maintained as a whole while maintaining the crystal structure. .
- the hydrogen content of strontium nitride used as a raw material is 500 ppm or less.
- the hydrogen content of the strontium nitride exceeds 500 ppm, the luminance of the phosphor tends to decrease.
- the fact that the hydrogen content of such strontium nitride is related to the luminance of the phosphor is a finding newly found by the inventors focusing on the hydrogen content of strontium nitride.
- a more preferable range of the hydrogen content of strontium nitride is 15 ppm or more and 500 ppm or less, and further preferably a range of 30 ppm or more and 480 ppm or less.
- the range of the hydrogen content of strontium nitride is more preferably 30 ppm or more and 380 ppm or less, and particularly preferably 30 ppm or more and 160 ppm, from the viewpoint of improving the emission intensity.
- hydrogen contained in strontium nitride used as a raw material may be, for example, in a Sr—H state or an O—H state bonded to surface oxygen. As good, the state contained in strontium nitride does not matter.
- inevitable hydrogen content in the strontium nitride used as the raw material may not be denied, but the upper limit value of the hydrogen content of the strontium nitride used as the raw material (that is, 500 ppm) can be preferably applied to hydrogen contained in strontium nitride obtained by reacting strontium metal obtained by reacting strontium metal with hydrogen and nitrogen.
- the method for producing a red phosphor containing strontium of the present invention does not particularly limit the origin until hydrogen is contained in strontium nitride and the method for producing strontium nitride. Therefore, in the present embodiment, the hydrogen contained in the strontium nitride is derived from, for example, a process for producing strontium nitride by reacting strontium hydride obtained by reacting metal strontium and hydrogen with nitrogen. Hydrogen derived from OH groups generated by surface alteration of strontium nitride may also be used.
- the strontium hydride is, for example, metal strontium in a hydrogen atmosphere at 100 ° C. to 200 ° C. (preferably 130 ° C. to 180 ° C.) for 6 hours to 24 hours (preferably 8 hours to 16 hours). It can be manufactured by heating and hydrotreating.
- the nitrogen strontium is, for example, strontium hydride at 500 ° C. to 1500 ° C. (preferably 500 ° C. to 1000 ° C.) in a nitrogen gas atmosphere for 0.5 to 12 hours (preferably 1 to 5 hours). ) It can be manufactured by heating and nitriding. Preferably, nitriding is performed if nitrogen gas is allowed to flow into the tubular furnace.
- strontium nitrogen after nitriding treatment it is preferable to collect strontium nitrogen after nitriding treatment to obtain strontium nitride used as a raw material in the method for producing a red phosphor of the present invention. After collection, it is preferable to classify and select only those that have passed through a sieve having an opening of 290 ⁇ m. Thereby, strontium nitride of 290 ⁇ m or less can be obtained.
- strontium nitride used as a raw material of the phosphor is another embodiment of the present invention, and the identification of the strontium nitride is based on the X-ray diffraction of the strontium nitride.
- the pattern can be compared with a JCPDS (Joint Committee on Power Diffraction Standards) card which is a database of X-ray diffraction patterns in crystal structure analysis.
- JCPDS Joint Committee on Power Diffraction Standards
- Sr 2 N, SrN, SrN 2 and Sr 4 N 3 are listed as strontium nitride.
- strontium nitride SrN, Sr 2 N or a mixture thereof having excellent stability
- a method for producing a red phosphor containing strontium according to the present invention for example, a production method similar to a conventional (Sr, Ca) AlSiN 3 phosphor can be used.
- the present invention is preferably a method for producing a red phosphor containing europium, and more preferably a method for producing a (Sr, Ca) AlSiN 3 phosphor containing strontium and europium.
- the plurality of raw materials preferably include at least a strontium compound, a calcium compound, an aluminum compound, and a silicon compound, and more preferably include a europium compound. These raw materials can be used alone or in combination.
- Each raw material is preferably a powder, and preferably passes through a sieve having an opening of 75 ⁇ m. Thereby, powder with a particle size of 75 ⁇ m or less can be obtained.
- the oxygen content rate of each raw material to be used 1.0 mass% or less is preferable.
- the raw material is set to have a molar ratio of Sr / (Ca + Sr) of the red phosphor of the present invention described above. It is preferable to adjust the mixture.
- a method for producing the (Sr, Ca) AlSiN 3 phosphor by firing a raw material mixed powder that can be formed by firing in a predetermined temperature range in a nitrogen atmosphere Illustrate.
- a nitride of an element constituting the red phosphor it is preferable to use a nitride of an element constituting the red phosphor as a raw material, but it is also possible to use an oxide.
- the red phosphor has the same crystal phase as (Sr, Ca) AlSiN 3 as a base crystal phase, that is, strontium nitride, calcium nitride, silicon nitride, aluminum nitride, and europium nitride are preferably used. It is also possible to use these oxides (for example, europium oxide, etc.).
- ⁇ -type silicon nitride these can be used alone or in combination.
- europium oxide which is easily available, may be used as a europium source with a very small addition amount because it acts as a luminescent center.
- the europium content in the raw material mixture is preferably within the preferable range of the Eu content in the raw material described above.
- the method for mixing the above-mentioned raw materials is not particularly limited.
- a compound that reacts violently with moisture and oxygen in the air for example, calcium nitride, strontium nitride, europium nitride, etc.
- it is replaced with an inert atmosphere. It is appropriate to handle in the glove box.
- One or two or more of these can be selected and used.
- an intermediate raw material mixture of a silicon compound, an aluminum compound and a europium compound in the mixing step.
- This intermediate raw material mixture can be obtained by ball-mixing a silicon compound, an aluminum compound and a europium compound in advance using a solvent and passing through a sieve having an opening of 75 ⁇ m after drying.
- the silicon compound is preferably ⁇ -type silicon nitride powder.
- the aluminum compound is preferably aluminum nitride powder.
- the europium compound is preferably europium oxide powder.
- the solvent is preferably an alcohol having 1 to 3 carbon atoms such as ethanol.
- the intermediate raw material mixture, the raw material strontium nitride, and the calcium compound are pulverized and mixed to obtain a final raw material mixture.
- the calcium compound is preferably calcium nitride.
- the blending ratio of (intermediate raw material mixture) :( raw material strontium nitride and calcium nitride) is preferably 45 to 55 mass%: 55 to 45 mass%.
- the firing container is preferably made of a material that is chemically stable in a high-temperature nitrogen atmosphere and hardly reacts with the raw material mixed powder and its reaction product, and examples thereof include containers made of boron nitride, carbon, and the like. It is done.
- a firing container filled with the raw material mixed powder is taken out from the glove box, and immediately set in a firing furnace, and the firing temperature is 1600 ° C. to 1950 ° C. (preferably 1600 ° C. to 1900 ° C.) in a nitrogen atmosphere.
- the temperature is preferably 1700 ° C. or higher and 1900 ° C. or lower.
- the firing temperature is lower than 1600 ° C., the amount of unreacted residue increases.
- the firing temperature is higher than 1950 ° C., the main crystal phase is decomposed.
- the firing time is no particular limitation on the firing time, but there are disadvantages that there are many unreacted raw materials, the growth of the main crystal phase of the red phosphor is insufficient, or the productivity of the red phosphor is significantly reduced.
- No firing time range is selected.
- the firing time is generally set in the range of 2 hours to 24 hours (preferably 2 hours to 12 hours, more preferably 2 hours to 6 hours).
- the pressure of the firing atmosphere is selected according to the firing temperature.
- the red phosphor obtained by the production method of the present invention is a phosphor having the same crystal phase as (Sr, Ca) AlSiN 3 as a host crystal phase, for example, the fluorescence is up to about 1800 ° C. under atmospheric pressure.
- the body can exist stably, it is preferable to set it in a pressurized atmosphere in order to suppress decomposition of the phosphor at a temperature higher than this.
- the higher the atmospheric pressure (MPaG; hereinafter referred to as “MPa”) the higher the decomposition temperature of the phosphor.
- it is less than 1 MPa (preferably 0.1 MPa or more, more preferably 0). 0.5 MPa or more and 0.9 MPa or less).
- the state of the fired product including the red phosphor after the firing step obtained by the method for producing the red phosphor of the present invention varies depending on the raw material composition and firing conditions, such as powder, lump, and sintered body. .
- the fired product obtained by combining crushing, grinding and / or classification operations is made into a powder of a predetermined size. For example, it is preferable to classify and select only those that have passed through a sieve having an opening of 45 ⁇ m.
- the fired product may be subjected to an acid treatment, or an annealing treatment may be further performed to improve the crystallinity of the red phosphor. good.
- the red phosphor obtained by the production method of the present invention is irradiated with light from a light source that emits ultraviolet light or visible light having a wavelength of 350 nm or more and 500 nm or less
- the red phosphor has a wavelength of 610 nm to around 650 nm. Emits red light with a fluorescent peak.
- a light emitting element that easily emits white light by combining a light emitting light source such as an ultraviolet LED or a blue LED and the red phosphor, and further combining a green to yellow phosphor and / or a blue phosphor as necessary. Obtainable.
- Example 1 Manufacture of strontium nitride> Metal strontium (made by Strem Chemicals Inc., 38-0074 grade, purity 99.9%) was placed in a pressure vessel, evacuated, filled with hydrogen, and heated at 150 ° C. for 12 hours for hydrogenation. . The obtained strontium hydride was set in a tubular furnace, and further heated at 700 ° C. for 3 hours while flowing nitrogen gas into the tubular furnace to nitride the strontium hydride. The obtained nitrogen strontium is recovered, and only those that have passed through a sieve having a mesh opening of 290 ⁇ m are classified and selected, and used as the red phosphor raw material. Obtained strontium nitride).
- Examples 2 to 4, Comparative Examples 1 to 3 The raw material strontium nitride of Examples 2 to 4 and Comparative Examples 1 to 3 was obtained in the same manner as in Example 1 except that the heating temperature and heating time of the nitriding treatment were changed. The results of these hydrogen contents are shown in Table 1 together with Example 1.
- Example 5 ⁇ Manufacture of red phosphor> ⁇ -type silicon nitride powder (SN-E10 grade, Ube Industries, Ltd., oxygen content 1.0 mass%) 52.2 mass%, aluminum nitride powder (E grade, Tokuyama Corp., oxygen content) 0.8 mass%) 45.8 mass%, europium oxide (RU grade made by Shin-Etsu Chemical Co., Ltd.) 2.0 mass%, using a nylon pot and silicon nitride balls, and ethanol as a solvent, mixing the ball mill went. After removing the solvent by drying, it was classified and sorted only through a sieve having an opening of 75 ⁇ m to obtain an intermediate raw material mixture from which aggregates had been removed.
- the final raw material mixture was obtained by further mixing with a mortar.
- the raw material mixture is filled in a cylindrical boron nitride container (N-1 grade, manufactured by Denki Kagaku Kogyo Co., Ltd.) with a lid in the glove box, taken out from the glove box, and immediately set in the electric furnace of the carbon heater.
- the inside of the electric furnace was sufficiently evacuated to 0.1 Pa or less. Heating was started with evacuation, and after reaching 600 ° C., nitrogen gas was introduced into the electric furnace, and the atmospheric pressure in the furnace was set to 0.9 MPa. After the introduction of nitrogen gas, the temperature was raised to 1800 ° C. as it was, and firing was performed at 1800 ° C. for 4 hours.
- the fired product was crushed using a ball mill and further classified with a vibrating sieve having an opening of 45 ⁇ m.
- the fired product after classification was subjected to powder X-ray diffraction using CuK ⁇ rays using an X-ray diffractometer (Uriga IV manufactured by Rigaku Corporation).
- the resulting X-ray diffraction pattern, (Sr, Ca) AlSiN 3 have the same crystalline phase same diffraction as pattern and, therefore, the main crystal phase of the baked product (Sr, Ca) AlSiN 3 identical crystal and It was confirmed that the phase was a host crystal phase, and the fired product was a red phosphor containing strontium.
- the amount of Ca and Sr contained in the obtained red phosphor is measured using an ICP emission spectroscopic analyzer (CIROS-120, manufactured by Rigaku Corporation) after dissolving the fired product by a pressure acid decomposition method. did. As a result, Sr / (Ca + Sr) in the fired product was 0.90 (molar ratio).
- the fluorescence spectrum of the red phosphor obtained in Example 1 was measured using a spectrofluorometer (F-7000, manufactured by Hitachi High-Technologies Corporation) corrected with rhodamine B and a sub-standard light source. For the measurement, a solid sample holder attached to the photometer was used, and a fluorescence spectrum at an excitation wavelength of 455 nm was obtained. The peak wavelength of the fluorescence spectrum was 630 nm. The results are shown in Table 2.
- the emission intensity in Table 2 was measured using the peak intensity of the fluorescence spectrum as an index. In the following examples and comparative examples, the peak intensity was measured using the same sampling method and conditions as in Example 5, and Example 5 was set to 100. % As a relative value, and when it was 100% or more, it was determined that the product had good luminance.
- Example 6 to 8 Comparative Examples 4 to 6
- the red fluorescence of Examples 6 to 8 and Comparative Examples 4 to 6 was the same as that of Example 5 except that the raw material strontium nitride was changed to strontium nitride produced in Examples 2 to 4 and Comparative Examples 1 to 3, respectively.
- the body was made. Further, the red phosphors of Examples 6 to 8 and Comparative Examples 4 to 6 were measured by the same method as that of Example 5, and are shown in Table 2 together with the results of Example 5.
- Example 9 A red phosphor of Example 9 was produced in the same manner as in Example 5 except that the raw material ratio was changed so that the Sr / (Sr + Ca) ratio was 0.75. The emission intensity was a relative value when Example 5 was taken as 100%. The results are shown in Table 3.
- Example 10 Comparative Examples 7 and 8
- the red phosphors of Example 10 and Comparative Examples 7 and 8 were produced in the same manner as Example 9 except that the strontium nitride was changed to the raw material strontium nitride prepared in Example 3 and Comparative Examples 1 and 2, respectively.
- the emission intensity was a relative value when Example 9 was 100%.
- the results are shown in Table 3 together with the results of Example 9.
- Example 11 A red phosphor of Example 11 was produced in the same manner as in Example 5 except that the raw material ratio was changed so that the Sr / (Sr + Ca) ratio was 0.40.
- Example 12 Comparative Examples 9, 10
- the phosphor powders of Example 12 and Comparative Examples 9 and 10 were produced in the same manner as Example 11 except that the raw material strontium was changed to the raw material strontium nitride prepared in Example 3 and Comparative Examples 1 and 2, respectively. .
- the emission intensity was a relative value when Example 11 was 100%.
- the results are shown in Table 4 together with the results of Example 11.
- a red phosphor obtained by the method for producing a red phosphor containing strontium according to the present invention for example, a phosphor having the same crystal phase as (Sr, Ca) AlSiN 3 as a host crystal, is excited by blue light and has a high luminance. Since it emits red light, it can be suitably used as a phosphor for white LEDs using blue light as a light source, and can be suitably used for light-emitting devices such as lighting fixtures and image display devices.
Abstract
A process for producing a red fluorescent substance having an excellent luminance is provided.
The process is for producing a red fluorescent substance containing strontium, and includes a burning step in which strontium nitride having a hydrogen content of 500 ppm or less is used as a starting material and a starting-material mixture containing the strontium nitride is burned. It is preferable that the production process should comprise a mixing step in which a plurality of starting materials are mixed and the burning step in which the starting-material mixture obtained in the mixing step is burned. It is preferable that the red fluorescent substance containing strontium be a red fluorescent substance comprising a base crystal phase having the same crystal phase as (Sr,Ca)AlSiN3.
Description
本発明は、赤色蛍光体の製造方法に関する。具体的には、本発明は、母体結晶が（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と実質的に同一の結晶構造を有する、ＬＥＤなどの発光素子の光を吸収して赤色を発光する、一般にＳＣＡＳＮ蛍光体と呼ばれる蛍光体の製造方法に関する。
The present invention relates to a method for producing a red phosphor. Specifically, the present invention generally provides a SCASN phosphor that absorbs light from a light emitting element such as an LED and emits red light, wherein the base crystal has substantially the same crystal structure as (Sr, Ca) AlSiN 3. The present invention relates to a method for manufacturing a phosphor called “a”.
白色ＬＥＤは、発光光源である半導体発光素子と、発光光源の比較的エネルギーが高く、波長の短い光の一部を励起光として吸収して、波長の長い別の色に変換する蛍光体との組み合わせにより疑似白色光を発光するデバイスであり、その代表的な組み合わせの例として、青色ＬＥＤとＹＡＧ（イットリウム・アルミニウム・ガーネット）黄色蛍光体が知られている。しかし、この組み合わせによる白色ＬＥＤは、その色度座標値としては白色領域に入るものの、赤色発光成分が不足しているために、照明用途では演色性が低く、液晶バックライトのような画像表示装置では色再現性が悪いという課題がある。
そのため、特許文献１には、不足している赤色発光成分を補うために、ＹＡＧ蛍光体とともに、赤色を発光する窒化物又は酸窒化物蛍光体を併用することが提案されている。 A white LED includes a semiconductor light-emitting element that is a light-emitting light source, and a phosphor that has a relatively high energy of the light-emitting light source and absorbs part of light with a short wavelength as excitation light and converts it to another color with a long wavelength. It is a device that emits pseudo white light by a combination, and a blue LED and a YAG (yttrium, aluminum, garnet) yellow phosphor are known as a typical example of the combination. However, the white LED by this combination is in the white region as its chromaticity coordinate value, but lacks a red light emitting component, so that the color rendering property is low for lighting use, and an image display device such as a liquid crystal backlight Then, there is a problem that color reproducibility is bad.
For this reason, Patent Document 1 proposes to use a nitride or oxynitride phosphor that emits red light together with a YAG phosphor in order to compensate for the insufficient red light-emitting component.
そのため、特許文献１には、不足している赤色発光成分を補うために、ＹＡＧ蛍光体とともに、赤色を発光する窒化物又は酸窒化物蛍光体を併用することが提案されている。 A white LED includes a semiconductor light-emitting element that is a light-emitting light source, and a phosphor that has a relatively high energy of the light-emitting light source and absorbs part of light with a short wavelength as excitation light and converts it to another color with a long wavelength. It is a device that emits pseudo white light by a combination, and a blue LED and a YAG (yttrium, aluminum, garnet) yellow phosphor are known as a typical example of the combination. However, the white LED by this combination is in the white region as its chromaticity coordinate value, but lacks a red light emitting component, so that the color rendering property is low for lighting use, and an image display device such as a liquid crystal backlight Then, there is a problem that color reproducibility is bad.
For this reason, Patent Document 1 proposes to use a nitride or oxynitride phosphor that emits red light together with a YAG phosphor in order to compensate for the insufficient red light-emitting component.
赤色を発光する窒化物蛍光体としては、ＣａＡｌＳｉＮ３と同一の結晶相を有する母体結晶に、光学活性な元素を付活した無機化合物が知られ、なかでもＥｕ２＋で付活（賦活ともいう）したＣａＡｌＳｉＮ３蛍光体は、特に高輝度で発光するとされている（例えば、特許文献２）。
また、特許文献２には、結晶相を維持したままＣａの一部をＳｒで置換することにより、発光ピーク波長が短波長側にシフトした蛍光体が得られることが記載されている。前記の蛍光体は、例えばＥｕ２＋で付活した（Ｓｒ，Ｃａ）ＡｌＳｉＮ３蛍光体と呼ばれ、ＣａＡｌＳｉＮ３蛍光体よりも発光波長が短く、視感度が高い領域のスペクトル成分が増える傾向にあることから、高輝度白色ＬＥＤ用の赤色蛍光体として有効である。 As a nitride phosphor that emits red light, an inorganic compound in which an optically active element is activated in a base crystal having the same crystal phase as CaAlSiN 3 is known, and in particular, activated by Eu 2+ (also called activation). The CaAlSiN 3 phosphor is said to emit light with particularly high luminance (for example, Patent Document 2).
Patent Document 2 describes that a phosphor having an emission peak wavelength shifted to the short wavelength side can be obtained by substituting part of Ca with Sr while maintaining the crystal phase. The phosphor is called, for example, a (Sr, Ca) AlSiN 3 phosphor activated by Eu 2+ , and tends to increase spectral components in a region having a shorter emission wavelength and higher visibility than the CaAlSiN 3 phosphor. Therefore, it is effective as a red phosphor for high brightness white LED.
また、特許文献２には、結晶相を維持したままＣａの一部をＳｒで置換することにより、発光ピーク波長が短波長側にシフトした蛍光体が得られることが記載されている。前記の蛍光体は、例えばＥｕ２＋で付活した（Ｓｒ，Ｃａ）ＡｌＳｉＮ３蛍光体と呼ばれ、ＣａＡｌＳｉＮ３蛍光体よりも発光波長が短く、視感度が高い領域のスペクトル成分が増える傾向にあることから、高輝度白色ＬＥＤ用の赤色蛍光体として有効である。 As a nitride phosphor that emits red light, an inorganic compound in which an optically active element is activated in a base crystal having the same crystal phase as CaAlSiN 3 is known, and in particular, activated by Eu 2+ (also called activation). The CaAlSiN 3 phosphor is said to emit light with particularly high luminance (for example, Patent Document 2).
Patent Document 2 describes that a phosphor having an emission peak wavelength shifted to the short wavelength side can be obtained by substituting part of Ca with Sr while maintaining the crystal phase. The phosphor is called, for example, a (Sr, Ca) AlSiN 3 phosphor activated by Eu 2+ , and tends to increase spectral components in a region having a shorter emission wavelength and higher visibility than the CaAlSiN 3 phosphor. Therefore, it is effective as a red phosphor for high brightness white LED.
しかし、ＣａＡｌＳｉＮ３蛍光体や（Ｓｒ，Ｃａ）ＡｌＳｉＮ３蛍光体などのＣａＡｌＳｉＮ３系窒化物蛍光体は、赤色でも特に波長の長い赤色領域までスペクトル成分を多く含むため、高い演色性を実現できる反面、視感度の低いスペクトル成分の割合も多くなり、白色ＬＥＤとしての輝度は全般的に低くなってしまう傾向にあるという問題点を有していた。
そのため、当業界では高い発光輝度の発光装置を提供するために、赤色蛍光体の高輝度化が期待されていた。 However, CaAlSiN 3 phosphor and (Sr, Ca) AlSiN 3 fluorescent material CaAlSiN 3 based nitride phosphor, such as, for containing many spectral components to long red region especially wavelengths in the red, while capable of realizing a high color rendering property However, the ratio of spectral components having low visibility is increased, and the luminance as a white LED generally tends to be low.
Therefore, in order to provide a light emitting device with high light emission luminance in the industry, it has been expected to increase the luminance of the red phosphor.
そのため、当業界では高い発光輝度の発光装置を提供するために、赤色蛍光体の高輝度化が期待されていた。 However, CaAlSiN 3 phosphor and (Sr, Ca) AlSiN 3 fluorescent material CaAlSiN 3 based nitride phosphor, such as, for containing many spectral components to long red region especially wavelengths in the red, while capable of realizing a high color rendering property However, the ratio of spectral components having low visibility is increased, and the luminance as a white LED generally tends to be low.
Therefore, in order to provide a light emitting device with high light emission luminance in the industry, it has been expected to increase the luminance of the red phosphor.
そこで、本発明は、輝度の優れた赤色蛍光体を製造する方法を提供することを主な目的とする。
Therefore, the main object of the present invention is to provide a method for producing a red phosphor having excellent luminance.
本発明者は、上記課題を解決すべく、赤色蛍光体、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３蛍光体を製造する際に使用する原料の一部に用いる窒化ストロンチウムについて鋭意検討した結果、水素含有率が特定の値以下にある窒化ストロンチウムを原料に用いると、高輝度を有する赤色蛍光体を製造することが可能となることを見出し、本発明の完成に至った。
The present inventors, in order to solve the above problems, the red phosphor, for example (Sr, Ca) AlSiN 3 As a result of intensive studies for strontium nitride which is used for a part of a raw material used in manufacturing the phosphor, hydrogen content When strontium nitride having a specific value of less than a specific value is used as a raw material, it has been found that a red phosphor having high luminance can be produced, and the present invention has been completed.
すなわち、本発明は、以下のとおりである。
（１）本発明は、水素含有率が５００ｐｐｍ以下である窒化ストロンチウムを原料として用い、当該窒化ストロンチウムを含む原料混合物を焼成する焼成工程を有する、ストロンチウムを含む赤色蛍光体の製造方法である。
（２）本発明は、水素含有率が５００ｐｐｍ以下である窒化ストロンチウムを原料として用い、複数の原料を混合する混合工程と、混合工程後の原料混合物を焼成する焼成工程を有する、ストロンチウムを含む赤色蛍光体の製造方法である。
（３）水素含有率が５００ｐｐｍ以下である窒化ストロンチウムが、金属ストロンチウムと水素とを反応させて得た水素化ストロンチウムと、窒素とを反応させたものである、前記（１）または（２）記載の赤色蛍光体の製造方法である。
（４）窒化ストロンチウムの水素含有率が１５ｐｐｍ以上である、前記（１）～前記（３）のいずれかひとつに記載の赤色蛍光体の製造方法である。
（５）ストロンチウムを含む赤色蛍光体が、（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とする赤色蛍光体である、前記（１）～前記（４）のいずれかひとつに記載の赤色蛍光体の製造方法である。
（６）前記原料混合物は少なくとも窒化ストロンチウムと窒化カルシウムを含むものであり、当該原料混合物におけるＳｒ／（Ｃａ＋Ｓｒ）＝０．３５～０．９５（モル数比）である、前記（１）～前記（５）のいずれかひとつに記載の赤色蛍光体の製造方法である。 That is, the present invention is as follows.
(1) The present invention is a method for producing a red phosphor containing strontium, which has a firing step of firing a raw material mixture containing strontium nitride using strontium nitride having a hydrogen content of 500 ppm or less as a raw material.
(2) The present invention uses strontium nitride having a hydrogen content of 500 ppm or less as a raw material, and includes a mixing step of mixing a plurality of raw materials, and a baking step of firing the raw material mixture after the mixing step, and a red color containing strontium It is a manufacturing method of fluorescent substance.
(3) The above (1) or (2), wherein the strontium nitride having a hydrogen content of 500 ppm or less is obtained by reacting strontium hydride obtained by reacting metal strontium with hydrogen and nitrogen. This is a method for producing a red phosphor.
(4) The method for producing a red phosphor according to any one of (1) to (3) above, wherein the hydrogen content of strontium nitride is 15 ppm or more.
(5) The red phosphor containing strontium is a red phosphor having the same crystal phase as (Sr, Ca) AlSiN 3 as a host crystal phase, described in any one of (1) to (4) above This is a method for producing a red phosphor.
(6) The raw material mixture contains at least strontium nitride and calcium nitride, and Sr / (Ca + Sr) = 0.35 to 0.95 (molar ratio) in the raw material mixture. (5) The method for producing a red phosphor according to any one of (5).
（１）本発明は、水素含有率が５００ｐｐｍ以下である窒化ストロンチウムを原料として用い、当該窒化ストロンチウムを含む原料混合物を焼成する焼成工程を有する、ストロンチウムを含む赤色蛍光体の製造方法である。
（２）本発明は、水素含有率が５００ｐｐｍ以下である窒化ストロンチウムを原料として用い、複数の原料を混合する混合工程と、混合工程後の原料混合物を焼成する焼成工程を有する、ストロンチウムを含む赤色蛍光体の製造方法である。
（３）水素含有率が５００ｐｐｍ以下である窒化ストロンチウムが、金属ストロンチウムと水素とを反応させて得た水素化ストロンチウムと、窒素とを反応させたものである、前記（１）または（２）記載の赤色蛍光体の製造方法である。
（４）窒化ストロンチウムの水素含有率が１５ｐｐｍ以上である、前記（１）～前記（３）のいずれかひとつに記載の赤色蛍光体の製造方法である。
（５）ストロンチウムを含む赤色蛍光体が、（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とする赤色蛍光体である、前記（１）～前記（４）のいずれかひとつに記載の赤色蛍光体の製造方法である。
（６）前記原料混合物は少なくとも窒化ストロンチウムと窒化カルシウムを含むものであり、当該原料混合物におけるＳｒ／（Ｃａ＋Ｓｒ）＝０．３５～０．９５（モル数比）である、前記（１）～前記（５）のいずれかひとつに記載の赤色蛍光体の製造方法である。 That is, the present invention is as follows.
(1) The present invention is a method for producing a red phosphor containing strontium, which has a firing step of firing a raw material mixture containing strontium nitride using strontium nitride having a hydrogen content of 500 ppm or less as a raw material.
(2) The present invention uses strontium nitride having a hydrogen content of 500 ppm or less as a raw material, and includes a mixing step of mixing a plurality of raw materials, and a baking step of firing the raw material mixture after the mixing step, and a red color containing strontium It is a manufacturing method of fluorescent substance.
(3) The above (1) or (2), wherein the strontium nitride having a hydrogen content of 500 ppm or less is obtained by reacting strontium hydride obtained by reacting metal strontium with hydrogen and nitrogen. This is a method for producing a red phosphor.
(4) The method for producing a red phosphor according to any one of (1) to (3) above, wherein the hydrogen content of strontium nitride is 15 ppm or more.
(5) The red phosphor containing strontium is a red phosphor having the same crystal phase as (Sr, Ca) AlSiN 3 as a host crystal phase, described in any one of (1) to (4) above This is a method for producing a red phosphor.
(6) The raw material mixture contains at least strontium nitride and calcium nitride, and Sr / (Ca + Sr) = 0.35 to 0.95 (molar ratio) in the raw material mixture. (5) The method for producing a red phosphor according to any one of (5).
本発明によれば、輝度の優れた赤色蛍光体を製造する方法を提供することができる。
本発明によれば、輝度の高い赤色蛍光体、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とし、ストロンチウムを含む赤色蛍光体の、製造方法を提供することができる。前記赤色蛍光体と、ＬＥＤ等の発光光源と組み合わせることで高輝度な発光素子を提供することができる。
なお、ここに記載された効果は、必ずしも限定されるものではなく、本明細書中に記載されたいずれかの効果であってもよい。 ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing red fluorescent substance excellent in the brightness | luminance can be provided.
According to the present invention, a high red phosphor luminance, for example (Sr, Ca) AlSiN 3 the same crystal phase as a host crystal phase, the red phosphor comprising strontium, it is possible to provide a manufacturing method. A high-luminance light emitting element can be provided by combining the red phosphor and a light emitting light source such as an LED.
Note that the effects described here are not necessarily limited, and may be any of the effects described in the present specification.
本発明によれば、輝度の高い赤色蛍光体、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とし、ストロンチウムを含む赤色蛍光体の、製造方法を提供することができる。前記赤色蛍光体と、ＬＥＤ等の発光光源と組み合わせることで高輝度な発光素子を提供することができる。
なお、ここに記載された効果は、必ずしも限定されるものではなく、本明細書中に記載されたいずれかの効果であってもよい。 ADVANTAGE OF THE INVENTION According to this invention, the method of manufacturing red fluorescent substance excellent in the brightness | luminance can be provided.
According to the present invention, a high red phosphor luminance, for example (Sr, Ca) AlSiN 3 the same crystal phase as a host crystal phase, the red phosphor comprising strontium, it is possible to provide a manufacturing method. A high-luminance light emitting element can be provided by combining the red phosphor and a light emitting light source such as an LED.
Note that the effects described here are not necessarily limited, and may be any of the effects described in the present specification.
以下、本発明を実施するための形態について、詳細に説明する。なお、以下に説明する実施形態は、本発明の実施形態の一例を示したものであり、これにより本発明の範囲が狭く解釈されることはない。
Hereinafter, embodiments for carrying out the present invention will be described in detail. In addition, embodiment described below shows an example of embodiment of this invention, and, thereby, the range of this invention is not interpreted narrowly.
本発明の実施により製造されるものは赤色蛍光体であり、前記赤色蛍光体の主結晶相は、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とするものである。
本明細書では便宜上、蛍光体の主結晶相の組成が一般式（Ｓｒ，Ｃａ）ＡｌＳｉＮ３で示されると記載するが、そのような組成の蛍光体が得られるように原料を配合しても、焼成時に蛍光体の組成が変動する可能性がある。本明細書に係る赤色蛍光体の組成は、そのような変動分をも包摂した表現である。
赤色蛍光体の主結晶相が、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相であるか否かは、粉末Ｘ線回折測定により確認することができる。
主結晶相が、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相になるように製造した赤色蛍光体の結晶構造が、（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と異なっている場合には、発光色が赤色ではなくなったり、蛍光強度が大きく低下したりするので、好ましくない。
主結晶相は、前記（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一で、単相の結晶であることが好ましいが、蛍光体特性に大きな影響がない限り、異相を含んでいても構わない。異相の有無は、例えば粉末Ｘ線回折により目的の結晶相によるもの以外のピークの有無により判別することができる。 What is manufactured by carrying out the present invention is a red phosphor, and the main crystal phase of the red phosphor is, for example, the same crystal phase as (Sr, Ca) AlSiN 3 as a base crystal phase.
In this specification, for convenience, it is described that the composition of the main crystal phase of the phosphor is represented by the general formula (Sr, Ca) AlSiN 3 , but the raw materials may be blended so as to obtain the phosphor having such a composition. The composition of the phosphor may fluctuate during firing. The composition of the red phosphor according to the present specification is an expression including such variation.
Whether or not the main crystal phase of the red phosphor is the same crystal phase as, for example, (Sr, Ca) AlSiN 3 can be confirmed by powder X-ray diffraction measurement.
The main crystal phase, for example (Sr, Ca) crystal structure of the red phosphor prepared to have the same crystalline phase and AlSiN 3 is (Sr, Ca) if different from the AlSiN 3, the light emitting color This is not preferable because it is no longer red or the fluorescence intensity is greatly reduced.
The main crystal phase is preferably the same as the (Sr, Ca) AlSiN 3 and a single-phase crystal, but may contain a different phase as long as the phosphor characteristics are not greatly affected. The presence or absence of a heterogeneous phase can be determined by the presence or absence of a peak other than that due to the target crystal phase, for example, by powder X-ray diffraction.
本明細書では便宜上、蛍光体の主結晶相の組成が一般式（Ｓｒ，Ｃａ）ＡｌＳｉＮ３で示されると記載するが、そのような組成の蛍光体が得られるように原料を配合しても、焼成時に蛍光体の組成が変動する可能性がある。本明細書に係る赤色蛍光体の組成は、そのような変動分をも包摂した表現である。
赤色蛍光体の主結晶相が、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相であるか否かは、粉末Ｘ線回折測定により確認することができる。
主結晶相が、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相になるように製造した赤色蛍光体の結晶構造が、（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と異なっている場合には、発光色が赤色ではなくなったり、蛍光強度が大きく低下したりするので、好ましくない。
主結晶相は、前記（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一で、単相の結晶であることが好ましいが、蛍光体特性に大きな影響がない限り、異相を含んでいても構わない。異相の有無は、例えば粉末Ｘ線回折により目的の結晶相によるもの以外のピークの有無により判別することができる。 What is manufactured by carrying out the present invention is a red phosphor, and the main crystal phase of the red phosphor is, for example, the same crystal phase as (Sr, Ca) AlSiN 3 as a base crystal phase.
In this specification, for convenience, it is described that the composition of the main crystal phase of the phosphor is represented by the general formula (Sr, Ca) AlSiN 3 , but the raw materials may be blended so as to obtain the phosphor having such a composition. The composition of the phosphor may fluctuate during firing. The composition of the red phosphor according to the present specification is an expression including such variation.
Whether or not the main crystal phase of the red phosphor is the same crystal phase as, for example, (Sr, Ca) AlSiN 3 can be confirmed by powder X-ray diffraction measurement.
The main crystal phase, for example (Sr, Ca) crystal structure of the red phosphor prepared to have the same crystalline phase and AlSiN 3 is (Sr, Ca) if different from the AlSiN 3, the light emitting color This is not preferable because it is no longer red or the fluorescence intensity is greatly reduced.
The main crystal phase is preferably the same as the (Sr, Ca) AlSiN 3 and a single-phase crystal, but may contain a different phase as long as the phosphor characteristics are not greatly affected. The presence or absence of a heterogeneous phase can be determined by the presence or absence of a peak other than that due to the target crystal phase, for example, by powder X-ray diffraction.
赤色蛍光体である、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３の結晶構造は、（Ｓｉ，Ａｌ）－Ｎ４正四面体を結合させた構成であり、その間隙にＳｒ原子及びＣａ原子が位置する結晶構造を有する。
この（Ｓｒ，Ｃａ）ＡｌＳｉＮ３において、結晶構造の間隙に位置するＳｒ２＋又はＣａ２＋の一部を、発光中心として作用するＥｕ２＋で置換すると、いわゆるＳＣＡＳＮ蛍光体と呼ばれる赤色蛍光体となる。 The crystal structure of, for example, (Sr, Ca) AlSiN 3 which is a red phosphor is a structure in which (Si, Al) -N4 tetrahedrons are bonded, and a crystal structure in which Sr atoms and Ca atoms are located in the gaps. Have
In this (Sr, Ca) AlSiN 3 , when a part of Sr 2+ or Ca 2+ located in the gap of the crystal structure is replaced with Eu 2+ acting as a luminescence center, a red phosphor called a so-called SCASN phosphor is obtained.
この（Ｓｒ，Ｃａ）ＡｌＳｉＮ３において、結晶構造の間隙に位置するＳｒ２＋又はＣａ２＋の一部を、発光中心として作用するＥｕ２＋で置換すると、いわゆるＳＣＡＳＮ蛍光体と呼ばれる赤色蛍光体となる。 The crystal structure of, for example, (Sr, Ca) AlSiN 3 which is a red phosphor is a structure in which (Si, Al) -N4 tetrahedrons are bonded, and a crystal structure in which Sr atoms and Ca atoms are located in the gaps. Have
In this (Sr, Ca) AlSiN 3 , when a part of Sr 2+ or Ca 2+ located in the gap of the crystal structure is replaced with Eu 2+ acting as a luminescence center, a red phosphor called a so-called SCASN phosphor is obtained.
本発明の赤色蛍光体が、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とする蛍光体である場合、ＳｒとＣａの比率は特に規定はされないが、高輝度を発現する好ましい範囲という観点から、Ｓｒ／（Ｃａ＋Ｓｒ）＝０．３５～０．９５（モル数比）であることが好ましく、更に好ましくはＳｒ／（Ｃａ＋Ｓｒ）＝０．４０～０．９０（モル数比）である。
When the red phosphor of the present invention is a phosphor having the same crystal phase as, for example, (Sr, Ca) AlSiN 3 as a host crystal phase, the ratio of Sr and Ca is not particularly defined, but expresses high luminance. From the viewpoint of a preferable range, it is preferably Sr / (Ca + Sr) = 0.35 to 0.95 (molar ratio), more preferably Sr / (Ca + Sr) = 0.40 to 0.90 (molar ratio). ).
Ｅｕ含有率は、あまりに少ないと発光への寄与が小さくなる傾向にあり、あまりに多いとＥｕ２＋相互間のエネルギー伝達による、一般に濃度消光と呼ばれる現象が起きやすくなる傾向にあるため、原料におけるＥｕ含有率は０．０１～０．４原子％とすることが好ましい。
原料におけるＥｕ含有率のより好ましい範囲は、０．０１～０．３原子％であり、更に好ましくは０．０４～０．２原子％であり、より更に好ましくは０．０６～０．１５原子％である。 If the Eu content is too small, the contribution to light emission tends to be small. If the Eu content is too large, a phenomenon generally called concentration quenching due to energy transfer between Eu 2+ tends to occur. The rate is preferably 0.01 to 0.4 atomic%.
A more preferable range of the Eu content in the raw material is 0.01 to 0.3 atom%, more preferably 0.04 to 0.2 atom%, and still more preferably 0.06 to 0.15 atom. %.
原料におけるＥｕ含有率のより好ましい範囲は、０．０１～０．３原子％であり、更に好ましくは０．０４～０．２原子％であり、より更に好ましくは０．０６～０．１５原子％である。 If the Eu content is too small, the contribution to light emission tends to be small. If the Eu content is too large, a phenomenon generally called concentration quenching due to energy transfer between Eu 2+ tends to occur. The rate is preferably 0.01 to 0.4 atomic%.
A more preferable range of the Eu content in the raw material is 0.01 to 0.3 atom%, more preferably 0.04 to 0.2 atom%, and still more preferably 0.06 to 0.15 atom. %.
本実施形態の製造方法により得られる蛍光体には、不可避的成分として微量の酸素（Ｏ）が含まれる。そして、蛍光体の組成パラメータであるＣａ及びＳｒの占有率、Ｓｉ／Ａｌ比、並びにＮ／Ｏ比などは、結晶構造を維持しながら全体として電気的中性が保たれるように調整される。
The phosphor obtained by the manufacturing method of the present embodiment contains a trace amount of oxygen (O) as an inevitable component. Then, the occupancy ratio of Ca and Sr, the Si / Al ratio, and the N / O ratio, which are the composition parameters of the phosphor, are adjusted so that the electrical neutrality is maintained as a whole while maintaining the crystal structure. .
本実施形態に係る赤色蛍光体の製造方法で、原料として用いる窒化ストロンチウムの水素含有率は５００ｐｐｍ以下である。
前記窒化ストロンチウムの水素含有率が５００ｐｐｍを超えると、蛍光体の輝度が低下する傾向にある。このような窒化ストロンチウムの水素含有率が蛍光体の輝度に関与することは、本発明者らが窒化ストロンチウムの水素含有率に着目したことにより、新たに見出した知見である。
なお、より好ましい窒化ストロンチウムの水素含有率の範囲は、１５ｐｐｍ以上５００ｐｐｍ以下であり、更に好ましくは３０ｐｐｍ以上４８０ｐｐｍ以下の範囲である。さらに窒化ストロンチウムの水素含有率の範囲は、発光強度向上の点から、より更に好ましくは３０ｐｐｍ以上３８０ｐｐｍ以下であり、特に好ましくは３０ｐｐｍ以上１６０ｐｐｍである。 In the method for producing a red phosphor according to this embodiment, the hydrogen content of strontium nitride used as a raw material is 500 ppm or less.
When the hydrogen content of the strontium nitride exceeds 500 ppm, the luminance of the phosphor tends to decrease. The fact that the hydrogen content of such strontium nitride is related to the luminance of the phosphor is a finding newly found by the inventors focusing on the hydrogen content of strontium nitride.
A more preferable range of the hydrogen content of strontium nitride is 15 ppm or more and 500 ppm or less, and further preferably a range of 30 ppm or more and 480 ppm or less. Furthermore, the range of the hydrogen content of strontium nitride is more preferably 30 ppm or more and 380 ppm or less, and particularly preferably 30 ppm or more and 160 ppm, from the viewpoint of improving the emission intensity.
前記窒化ストロンチウムの水素含有率が５００ｐｐｍを超えると、蛍光体の輝度が低下する傾向にある。このような窒化ストロンチウムの水素含有率が蛍光体の輝度に関与することは、本発明者らが窒化ストロンチウムの水素含有率に着目したことにより、新たに見出した知見である。
なお、より好ましい窒化ストロンチウムの水素含有率の範囲は、１５ｐｐｍ以上５００ｐｐｍ以下であり、更に好ましくは３０ｐｐｍ以上４８０ｐｐｍ以下の範囲である。さらに窒化ストロンチウムの水素含有率の範囲は、発光強度向上の点から、より更に好ましくは３０ｐｐｍ以上３８０ｐｐｍ以下であり、特に好ましくは３０ｐｐｍ以上１６０ｐｐｍである。 In the method for producing a red phosphor according to this embodiment, the hydrogen content of strontium nitride used as a raw material is 500 ppm or less.
When the hydrogen content of the strontium nitride exceeds 500 ppm, the luminance of the phosphor tends to decrease. The fact that the hydrogen content of such strontium nitride is related to the luminance of the phosphor is a finding newly found by the inventors focusing on the hydrogen content of strontium nitride.
A more preferable range of the hydrogen content of strontium nitride is 15 ppm or more and 500 ppm or less, and further preferably a range of 30 ppm or more and 480 ppm or less. Furthermore, the range of the hydrogen content of strontium nitride is more preferably 30 ppm or more and 380 ppm or less, and particularly preferably 30 ppm or more and 160 ppm, from the viewpoint of improving the emission intensity.
本実施形態に係る赤色蛍光体の製造方法で、原料として用いる窒化ストロンチウムに含有される水素は、例えばＳｒ－Ｈの状態であっても、表面酸素に結合したＯ－Ｈの状態であっても良いように、窒化ストロンチウムに含まれている状態は問わない。
なお、本実施形態に係る赤色蛍光体の製造方法では、原料として用いる窒化ストロンチウムへの不可避的な水素の含有が否定できない場合があるが、原料として用いる窒化ストロンチウムの水素含有率の上限値（即ち５００ｐｐｍ）については、金属ストロンチウムと水素とを反応させて得た水素化ストロンチウムと、窒素とを反応させることにより得た窒化ストロンチウムに含まれる水素に関して好ましく適用することができる。ただし、本発明のストロンチウムを含む赤色蛍光体の製造方法は、特に窒化ストロンチウムに水素が含有されるまでの由来や窒化ストロンチウムの製法までを限定するものではない。
従って、本実施形態において、前記窒化ストロンチウムに含有される水素は、例えば、金属ストロンチウムと水素とを反応させて得た水素化ストロンチウムと、窒素とを反応させることにより窒化ストロンチウムを製造するプロセスに由来する水素であっても良いし、窒化ストロンチウムの表面変質によって生じるＯ－Ｈ基由来の水素であっても良い。 In the method for producing a red phosphor according to the present embodiment, hydrogen contained in strontium nitride used as a raw material may be, for example, in a Sr—H state or an O—H state bonded to surface oxygen. As good, the state contained in strontium nitride does not matter.
In addition, in the manufacturing method of the red phosphor according to the present embodiment, inevitable hydrogen content in the strontium nitride used as the raw material may not be denied, but the upper limit value of the hydrogen content of the strontium nitride used as the raw material (that is, 500 ppm) can be preferably applied to hydrogen contained in strontium nitride obtained by reacting strontium metal obtained by reacting strontium metal with hydrogen and nitrogen. However, the method for producing a red phosphor containing strontium of the present invention does not particularly limit the origin until hydrogen is contained in strontium nitride and the method for producing strontium nitride.
Therefore, in the present embodiment, the hydrogen contained in the strontium nitride is derived from, for example, a process for producing strontium nitride by reacting strontium hydride obtained by reacting metal strontium and hydrogen with nitrogen. Hydrogen derived from OH groups generated by surface alteration of strontium nitride may also be used.
なお、本実施形態に係る赤色蛍光体の製造方法では、原料として用いる窒化ストロンチウムへの不可避的な水素の含有が否定できない場合があるが、原料として用いる窒化ストロンチウムの水素含有率の上限値（即ち５００ｐｐｍ）については、金属ストロンチウムと水素とを反応させて得た水素化ストロンチウムと、窒素とを反応させることにより得た窒化ストロンチウムに含まれる水素に関して好ましく適用することができる。ただし、本発明のストロンチウムを含む赤色蛍光体の製造方法は、特に窒化ストロンチウムに水素が含有されるまでの由来や窒化ストロンチウムの製法までを限定するものではない。
従って、本実施形態において、前記窒化ストロンチウムに含有される水素は、例えば、金属ストロンチウムと水素とを反応させて得た水素化ストロンチウムと、窒素とを反応させることにより窒化ストロンチウムを製造するプロセスに由来する水素であっても良いし、窒化ストロンチウムの表面変質によって生じるＯ－Ｈ基由来の水素であっても良い。 In the method for producing a red phosphor according to the present embodiment, hydrogen contained in strontium nitride used as a raw material may be, for example, in a Sr—H state or an O—H state bonded to surface oxygen. As good, the state contained in strontium nitride does not matter.
In addition, in the manufacturing method of the red phosphor according to the present embodiment, inevitable hydrogen content in the strontium nitride used as the raw material may not be denied, but the upper limit value of the hydrogen content of the strontium nitride used as the raw material (that is, 500 ppm) can be preferably applied to hydrogen contained in strontium nitride obtained by reacting strontium metal obtained by reacting strontium metal with hydrogen and nitrogen. However, the method for producing a red phosphor containing strontium of the present invention does not particularly limit the origin until hydrogen is contained in strontium nitride and the method for producing strontium nitride.
Therefore, in the present embodiment, the hydrogen contained in the strontium nitride is derived from, for example, a process for producing strontium nitride by reacting strontium hydride obtained by reacting metal strontium and hydrogen with nitrogen. Hydrogen derived from OH groups generated by surface alteration of strontium nitride may also be used.
前記水素化ストロンチウムは、例えば、金属ストロンチウムを、水素雰囲気下にて、１００℃～２００℃（好適には１３０℃～１８０℃）で、６時間～２４時間（好適には８時間～１６時間）加熱し、水素化処理するにより製造することができる。
前記窒素ストロンチウムは、例えば、水素化ストロンチウムを、窒素ガス雰囲気下にて、５００℃～１５００℃（好適には５００℃～１０００℃）で、０．５～１２時間（好適には１～５時間）加熱し、窒化処理することにより製造することができる。好適には、窒素ガスを管状炉内に流しなら窒化処理を行うことが好ましい。
さらに、窒化処理後の窒素ストロンチウムを回収し、本発明の赤色蛍光体の製造方法で原料として用いる窒化ストロンチウムとすることが好ましい。
回収後、目開き２９０μｍの篩を通過したものだけを分級選別することが好ましい。これにより、２９０μｍ以下の窒化ストロンチウムを得ることができる。 The strontium hydride is, for example, metal strontium in a hydrogen atmosphere at 100 ° C. to 200 ° C. (preferably 130 ° C. to 180 ° C.) for 6 hours to 24 hours (preferably 8 hours to 16 hours). It can be manufactured by heating and hydrotreating.
The nitrogen strontium is, for example, strontium hydride at 500 ° C. to 1500 ° C. (preferably 500 ° C. to 1000 ° C.) in a nitrogen gas atmosphere for 0.5 to 12 hours (preferably 1 to 5 hours). ) It can be manufactured by heating and nitriding. Preferably, nitriding is performed if nitrogen gas is allowed to flow into the tubular furnace.
Furthermore, it is preferable to collect strontium nitrogen after nitriding treatment to obtain strontium nitride used as a raw material in the method for producing a red phosphor of the present invention.
After collection, it is preferable to classify and select only those that have passed through a sieve having an opening of 290 μm. Thereby, strontium nitride of 290 μm or less can be obtained.
前記窒素ストロンチウムは、例えば、水素化ストロンチウムを、窒素ガス雰囲気下にて、５００℃～１５００℃（好適には５００℃～１０００℃）で、０．５～１２時間（好適には１～５時間）加熱し、窒化処理することにより製造することができる。好適には、窒素ガスを管状炉内に流しなら窒化処理を行うことが好ましい。
さらに、窒化処理後の窒素ストロンチウムを回収し、本発明の赤色蛍光体の製造方法で原料として用いる窒化ストロンチウムとすることが好ましい。
回収後、目開き２９０μｍの篩を通過したものだけを分級選別することが好ましい。これにより、２９０μｍ以下の窒化ストロンチウムを得ることができる。 The strontium hydride is, for example, metal strontium in a hydrogen atmosphere at 100 ° C. to 200 ° C. (preferably 130 ° C. to 180 ° C.) for 6 hours to 24 hours (preferably 8 hours to 16 hours). It can be manufactured by heating and hydrotreating.
The nitrogen strontium is, for example, strontium hydride at 500 ° C. to 1500 ° C. (preferably 500 ° C. to 1000 ° C.) in a nitrogen gas atmosphere for 0.5 to 12 hours (preferably 1 to 5 hours). ) It can be manufactured by heating and nitriding. Preferably, nitriding is performed if nitrogen gas is allowed to flow into the tubular furnace.
Furthermore, it is preferable to collect strontium nitrogen after nitriding treatment to obtain strontium nitride used as a raw material in the method for producing a red phosphor of the present invention.
After collection, it is preferable to classify and select only those that have passed through a sieve having an opening of 290 μm. Thereby, strontium nitride of 290 μm or less can be obtained.
なお本発明のストロンチウムを含む赤色蛍光体の製造方法において、蛍光体の原料として用いる窒化ストロンチウムは、本発明のもう一つの実施形態でもあり、その窒化ストロンチウムの同定は、前記窒化ストロンチウムのＸ線回折パターンと、結晶構造解析におけるＸ線回折パターンのデータベースであるＪＣＰＤＳ（Ｊｏｉｎｔ Ｃｏｍｍｉｔｔｅｅ ｏｎ Ｐｏｗｅｒ Ｄｉｆｆｒａｃｔｉｏｎ Ｓｔａｎｄａｒｄｓ）カードとの比較を行なうことでできる。このＪＣＰＤＳカードには、窒化ストロンチウムとして、Ｓｒ２Ｎ、ＳｒＮ、ＳｒＮ２及びＳｒ４Ｎ３が掲載されているが、各種窒化ストロンチウムの中でも、安定性に優れるＳｒＮ、Ｓｒ２Ｎ又はこれらの混合体を主結晶相とする窒化ストロンチウム（Ｓｒ３Ｎ２）が好ましい。
In the method for producing a red phosphor containing strontium according to the present invention, strontium nitride used as a raw material of the phosphor is another embodiment of the present invention, and the identification of the strontium nitride is based on the X-ray diffraction of the strontium nitride. The pattern can be compared with a JCPDS (Joint Committee on Power Diffraction Standards) card which is a database of X-ray diffraction patterns in crystal structure analysis. In this JCPDS card, Sr 2 N, SrN, SrN 2 and Sr 4 N 3 are listed as strontium nitride. Among various strontium nitrides, SrN, Sr 2 N or a mixture thereof having excellent stability Preferred is strontium nitride (Sr 3 N 2 ) having a main crystal phase.
本発明のストロンチウムを含む赤色蛍光体の製造方法は、例えば従来の（Ｓｒ，Ｃａ）ＡｌＳｉＮ３蛍光体と同様の製造方法を用いることができる。本発明は、好適には、さらにユーロピウムを含む赤色蛍光体の製造方法であり、より好適には、ストロンチウム及びユーロピウムを含む（Ｓｒ，Ｃａ）ＡｌＳｉＮ３蛍光体の製造方法である。
本発明の製造方法において、前述した水素含有率が５００ｐｐｍ以下である窒化ストロンチウムを原料として少なくとも用いることが好ましい。 As a method for producing a red phosphor containing strontium according to the present invention, for example, a production method similar to a conventional (Sr, Ca) AlSiN 3 phosphor can be used. The present invention is preferably a method for producing a red phosphor containing europium, and more preferably a method for producing a (Sr, Ca) AlSiN 3 phosphor containing strontium and europium.
In the production method of the present invention, it is preferable to use at least strontium nitride having a hydrogen content of 500 ppm or less as a raw material.
本発明の製造方法において、前述した水素含有率が５００ｐｐｍ以下である窒化ストロンチウムを原料として少なくとも用いることが好ましい。 As a method for producing a red phosphor containing strontium according to the present invention, for example, a production method similar to a conventional (Sr, Ca) AlSiN 3 phosphor can be used. The present invention is preferably a method for producing a red phosphor containing europium, and more preferably a method for producing a (Sr, Ca) AlSiN 3 phosphor containing strontium and europium.
In the production method of the present invention, it is preferable to use at least strontium nitride having a hydrogen content of 500 ppm or less as a raw material.
さらに、複数の原料を混合する工程であって、当該原料に水素含有率が５００ｐｐｍ以下である窒化ストロンチウムを含有する混合工程と、混合工程後の原料混合物を焼成する焼成工程とを、含むことが好適である。前記複数の原料は、少なくともストロンチウム化合物、カルシウム化合物、アルミニウム化合物及びケイ素化合物を含むものが好適であり、さらにユーロピウム化合物を含むものがより好適である。これら原料は単独で又は組み合わせて使用することも可能である。
各原料は粉末であることが好ましく、目開き７５μｍの篩を通過するものが好ましい。これにより、粒径７５μｍ以下の粉末を得ることができる。
使用する各原料の酸素含有率は、１．０ｍａｓｓ％以下が好ましい。 Furthermore, it is a step of mixing a plurality of raw materials, and includes a mixing step in which the raw material contains strontium nitride having a hydrogen content of 500 ppm or less, and a firing step in which the raw material mixture after the mixing step is fired. Is preferred. The plurality of raw materials preferably include at least a strontium compound, a calcium compound, an aluminum compound, and a silicon compound, and more preferably include a europium compound. These raw materials can be used alone or in combination.
Each raw material is preferably a powder, and preferably passes through a sieve having an opening of 75 μm. Thereby, powder with a particle size of 75 μm or less can be obtained.
As for the oxygen content rate of each raw material to be used, 1.0 mass% or less is preferable.
各原料は粉末であることが好ましく、目開き７５μｍの篩を通過するものが好ましい。これにより、粒径７５μｍ以下の粉末を得ることができる。
使用する各原料の酸素含有率は、１．０ｍａｓｓ％以下が好ましい。 Furthermore, it is a step of mixing a plurality of raw materials, and includes a mixing step in which the raw material contains strontium nitride having a hydrogen content of 500 ppm or less, and a firing step in which the raw material mixture after the mixing step is fired. Is preferred. The plurality of raw materials preferably include at least a strontium compound, a calcium compound, an aluminum compound, and a silicon compound, and more preferably include a europium compound. These raw materials can be used alone or in combination.
Each raw material is preferably a powder, and preferably passes through a sieve having an opening of 75 μm. Thereby, powder with a particle size of 75 μm or less can be obtained.
As for the oxygen content rate of each raw material to be used, 1.0 mass% or less is preferable.
また、（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とする赤色蛍光体を製造する場合、上述した本発明の赤色蛍光体のＳｒ／（Ｃａ＋Ｓｒ）のモル比となるように原料混合物を調整することが好ましい。具体的には、混合工程における原料混合物のＳｒ／（Ｃａ＋Ｓｒ）のモル比が、好ましくはＳｒ／（Ｃａ＋Ｓｒ）＝０．３５～０．９５（モル数比）、より好ましくはＳｒ／（Ｃａ＋Ｓｒ）＝０．４０～０．９０（モル数比）であることが、好適である。
Further, when a red phosphor having the same crystal phase as (Sr, Ca) AlSiN 3 as a base crystal phase is produced, the raw material is set to have a molar ratio of Sr / (Ca + Sr) of the red phosphor of the present invention described above. It is preferable to adjust the mixture. Specifically, the Sr / (Ca + Sr) molar ratio of the raw material mixture in the mixing step is preferably Sr / (Ca + Sr) = 0.35 to 0.95 (molar ratio), more preferably Sr / (Ca + Sr). = 0.40-0.90 (molar ratio) is preferred.
ここでは、本発明の一つの実施形態として、前記（Ｓｒ，Ｃａ）ＡｌＳｉＮ３蛍光体を、焼成により構成しうる原料混合粉末を、窒素雰囲気中において所定の温度範囲で焼成して製造する方法を例示する。
Here, as one embodiment of the present invention, a method for producing the (Sr, Ca) AlSiN 3 phosphor by firing a raw material mixed powder that can be formed by firing in a predetermined temperature range in a nitrogen atmosphere. Illustrate.
この製造方法では、原料として赤色蛍光体を構成する元素の窒化物を用いることが好ましいが、酸化物を使用することも可能である。
例えば、赤色蛍光体が（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とする場合は、即ち窒化ストロンチウム、窒化カルシウム、窒化ケイ素、窒化アルミニウム、窒化ユーロピウムが好適に使用されるが、これらの酸化物（例えば、酸化ユーロピウムなど）を使用することも可能である。また、窒化ケイ素はα型を使用することが好ましい。これらは単独で又は組み合わせて使用することも可能である。
例えば、発光中心として作用することから添加量が非常に少ないユーロピウム源として、入手が容易な酸化ユーロピウムを使用しても構わない。前記原料混合物にユーロピウムを含む場合、前記原料混合物中のユーロピウム含有率は、上述した原料におけるＥｕ含有率の好ましい範囲内であることが好ましい。 In this manufacturing method, it is preferable to use a nitride of an element constituting the red phosphor as a raw material, but it is also possible to use an oxide.
For example, when the red phosphor has the same crystal phase as (Sr, Ca) AlSiN 3 as a base crystal phase, that is, strontium nitride, calcium nitride, silicon nitride, aluminum nitride, and europium nitride are preferably used. It is also possible to use these oxides (for example, europium oxide, etc.). In addition, it is preferable to use α-type silicon nitride. These can be used alone or in combination.
For example, europium oxide, which is easily available, may be used as a europium source with a very small addition amount because it acts as a luminescent center. When europium is included in the raw material mixture, the europium content in the raw material mixture is preferably within the preferable range of the Eu content in the raw material described above.
例えば、赤色蛍光体が（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とする場合は、即ち窒化ストロンチウム、窒化カルシウム、窒化ケイ素、窒化アルミニウム、窒化ユーロピウムが好適に使用されるが、これらの酸化物（例えば、酸化ユーロピウムなど）を使用することも可能である。また、窒化ケイ素はα型を使用することが好ましい。これらは単独で又は組み合わせて使用することも可能である。
例えば、発光中心として作用することから添加量が非常に少ないユーロピウム源として、入手が容易な酸化ユーロピウムを使用しても構わない。前記原料混合物にユーロピウムを含む場合、前記原料混合物中のユーロピウム含有率は、上述した原料におけるＥｕ含有率の好ましい範囲内であることが好ましい。 In this manufacturing method, it is preferable to use a nitride of an element constituting the red phosphor as a raw material, but it is also possible to use an oxide.
For example, when the red phosphor has the same crystal phase as (Sr, Ca) AlSiN 3 as a base crystal phase, that is, strontium nitride, calcium nitride, silicon nitride, aluminum nitride, and europium nitride are preferably used. It is also possible to use these oxides (for example, europium oxide, etc.). In addition, it is preferable to use α-type silicon nitride. These can be used alone or in combination.
For example, europium oxide, which is easily available, may be used as a europium source with a very small addition amount because it acts as a luminescent center. When europium is included in the raw material mixture, the europium content in the raw material mixture is preferably within the preferable range of the Eu content in the raw material described above.
上述した原料を混合する方法は特に限定されないが、例えば、空気中の水分及び酸素と激しく反応する化合物（例えば、窒化カルシウム、窒化ストロンチウム、窒化ユーロピウム等）を用いる場合は不活性雰囲気で置換されたグローブボックス内で取り扱うことが適切である。これらから１種又は２種以上のものを選択し使用することも可能である。
The method for mixing the above-mentioned raw materials is not particularly limited. For example, when a compound that reacts violently with moisture and oxygen in the air (for example, calcium nitride, strontium nitride, europium nitride, etc.) is used, it is replaced with an inert atmosphere. It is appropriate to handle in the glove box. One or two or more of these can be selected and used.
さらに、混合工程において、ケイ素化合物、アルミニウム化合物及びユーロピウム化合物の中間原料混合物を使用することが好適である。この中間原料混合物は、ケイ素化合物、アルミニウム化合物及びユーロピウム化合物を、予め溶媒使用のボールミル混合を行い、乾燥後に目開き７５μｍの篩を通過して得ることができる。前記ケイ素化合物は、α型窒化ケイ素粉末であることが好適である。前記アルミニウム化合物は、窒化アルミニウム粉末であることが好適である。前記ユーロピウム化合物は、酸化ユーロピウム粉末であることが好適である。前記溶媒は、エタノール等の炭素数１～３のアルコールであることが好ましい。
Furthermore, it is preferable to use an intermediate raw material mixture of a silicon compound, an aluminum compound and a europium compound in the mixing step. This intermediate raw material mixture can be obtained by ball-mixing a silicon compound, an aluminum compound and a europium compound in advance using a solvent and passing through a sieve having an opening of 75 μm after drying. The silicon compound is preferably α-type silicon nitride powder. The aluminum compound is preferably aluminum nitride powder. The europium compound is preferably europium oxide powder. The solvent is preferably an alcohol having 1 to 3 carbon atoms such as ethanol.
混合工程において、前記中間原料混合物と、原料窒化ストロンチウム及びカルシウム化合物とを粉砕混合して、最終の原料混合物とすることが、好適である。前記カルシウム化合物は、窒化カルシウムであることが好適である。（中間原料混合物）：（原料窒化ストロンチウムと窒化カルシウム）の配合比率は、４５～５５ｍａｓｓ％：５５～４５ｍａｓｓ％であることが好ましい。
In the mixing step, it is preferable that the intermediate raw material mixture, the raw material strontium nitride, and the calcium compound are pulverized and mixed to obtain a final raw material mixture. The calcium compound is preferably calcium nitride. The blending ratio of (intermediate raw material mixture) :( raw material strontium nitride and calcium nitride) is preferably 45 to 55 mass%: 55 to 45 mass%.
焼成容器は、高温の窒素雰囲気下において化学的に安定で、原料混合粉末及びその反応生成物と反応しにくい材質で構成されることが好ましく、例えば、窒化ホウ素製、カーボン製などの容器が挙げられる。
The firing container is preferably made of a material that is chemically stable in a high-temperature nitrogen atmosphere and hardly reacts with the raw material mixed powder and its reaction product, and examples thereof include containers made of boron nitride, carbon, and the like. It is done.
焼成については、例えばグローブボックスから、原料混合粉末を充填した焼成容器を取り出し、速やかに焼成炉内にセットし、窒素雰囲気中で、焼成温度１６００℃以上１９５０℃以下（好適には１６００℃以上１９００℃以下）で焼成することが好ましく、さらに１７００℃以上１９００℃以下が好ましい。焼成温度が１６００℃より低いと未反応残存量が多くなり、１９５０℃より高いと主結晶相が分解するので、焼成温度１６００℃以上１９５０℃以下が好ましい。
For firing, for example, a firing container filled with the raw material mixed powder is taken out from the glove box, and immediately set in a firing furnace, and the firing temperature is 1600 ° C. to 1950 ° C. (preferably 1600 ° C. to 1900 ° C.) in a nitrogen atmosphere. The temperature is preferably 1700 ° C. or higher and 1900 ° C. or lower. When the firing temperature is lower than 1600 ° C., the amount of unreacted residue increases. When the firing temperature is higher than 1950 ° C., the main crystal phase is decomposed.
焼成時間に特に限定はないが、原料の未反応物が多く存在したり、赤色蛍光体の主結晶相の成長が不足したり、或いは赤色蛍光体の生産性が著しく低下したりという不都合が生じない焼成時間の範囲が選択される。本発明の好ましい実施形態では、焼成時間は一般に２時間以上２４時間以下（好適には２時間以上１２時間以下、さらに好適には２時間以上６時間以下）の範囲内に設定される。
There is no particular limitation on the firing time, but there are disadvantages that there are many unreacted raw materials, the growth of the main crystal phase of the red phosphor is insufficient, or the productivity of the red phosphor is significantly reduced. No firing time range is selected. In a preferred embodiment of the present invention, the firing time is generally set in the range of 2 hours to 24 hours (preferably 2 hours to 12 hours, more preferably 2 hours to 6 hours).
焼成雰囲気の圧力は、焼成温度に応じて選択される。本発明の製造方法により得られる赤色蛍光体が、例えば、（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とする蛍光体である場合、大気圧下で約１８００℃までは前記蛍光体は安定して存在することができるが、これ以上の温度では前記蛍光体の分解を抑制するため、加圧雰囲気に設定することが好ましい。雰囲気圧力（ＭＰａＧ；以下「ＭＰａ」とする）が高いほど、前記蛍光体の分解温度は高くなるが、工業的生産性を考慮すると１ＭＰａ未満（好適には０．１ＭＰａ以上、より好適には０．５ＭＰａ以上０．９ＭＰａ以下）とすることが好ましい。
The pressure of the firing atmosphere is selected according to the firing temperature. When the red phosphor obtained by the production method of the present invention is a phosphor having the same crystal phase as (Sr, Ca) AlSiN 3 as a host crystal phase, for example, the fluorescence is up to about 1800 ° C. under atmospheric pressure. Although the body can exist stably, it is preferable to set it in a pressurized atmosphere in order to suppress decomposition of the phosphor at a temperature higher than this. The higher the atmospheric pressure (MPaG; hereinafter referred to as “MPa”), the higher the decomposition temperature of the phosphor. However, considering industrial productivity, it is less than 1 MPa (preferably 0.1 MPa or more, more preferably 0). 0.5 MPa or more and 0.9 MPa or less).
本発明の赤色蛍光体の製造方法で得られた、焼成工程後の赤色蛍光体を含む焼成物の状態は、原料配合や焼成条件によって、粉体状、塊状、焼結体状と様々である。蛍光体として使用する場合には、解砕、粉砕及び／又は分級操作を組み合わせて得られた前記焼成物を所定のサイズの粉末にする。例えば、目開き４５μｍの篩を通過したものだけを分級選別することが好ましい。
ＬＥＤ用蛍光体として好適に使用する場合には、焼成物の平均粒径が５～３０μｍとなるように調整することが好ましい。 The state of the fired product including the red phosphor after the firing step obtained by the method for producing the red phosphor of the present invention varies depending on the raw material composition and firing conditions, such as powder, lump, and sintered body. . When used as a phosphor, the fired product obtained by combining crushing, grinding and / or classification operations is made into a powder of a predetermined size. For example, it is preferable to classify and select only those that have passed through a sieve having an opening of 45 μm.
When suitably used as an LED phosphor, it is preferable to adjust the average particle size of the fired product to 5 to 30 μm.
ＬＥＤ用蛍光体として好適に使用する場合には、焼成物の平均粒径が５～３０μｍとなるように調整することが好ましい。 The state of the fired product including the red phosphor after the firing step obtained by the method for producing the red phosphor of the present invention varies depending on the raw material composition and firing conditions, such as powder, lump, and sintered body. . When used as a phosphor, the fired product obtained by combining crushing, grinding and / or classification operations is made into a powder of a predetermined size. For example, it is preferable to classify and select only those that have passed through a sieve having an opening of 45 μm.
When suitably used as an LED phosphor, it is preferable to adjust the average particle size of the fired product to 5 to 30 μm.
前記赤色蛍光体を含む焼成物に含まれる不純物を除去する目的で、前記焼成物に酸処理を施したり、赤色蛍光体の結晶性を向上する目的で、アニール処理を更に実施したりしても良い。
For the purpose of removing impurities contained in the fired product containing the red phosphor, the fired product may be subjected to an acid treatment, or an annealing treatment may be further performed to improve the crystallinity of the red phosphor. good.
本発明の製造方法により得られた赤色蛍光体は、３５０ｎｍ以上５００ｎｍ以下の波長を含有する紫外光や可視光を放射する発光光源の光を照射すると、前記赤色蛍光体は、波長６１０ｎｍから６５０ｎｍ近傍に蛍光ピークのある赤色光を発する。特に紫外ＬＥＤ又は青色ＬＥＤといった発光光源と、前記赤色蛍光体とを組み合わせ、必要に応じてさらに緑～黄色蛍光体及び／又は青色蛍光体とを組み合わせることにより、容易に白色光を発する発光素子を得ることができる。
When the red phosphor obtained by the production method of the present invention is irradiated with light from a light source that emits ultraviolet light or visible light having a wavelength of 350 nm or more and 500 nm or less, the red phosphor has a wavelength of 610 nm to around 650 nm. Emits red light with a fluorescent peak. In particular, a light emitting element that easily emits white light by combining a light emitting light source such as an ultraviolet LED or a blue LED and the red phosphor, and further combining a green to yellow phosphor and / or a blue phosphor as necessary. Obtainable.
以下、実施例及び比較例を挙げて、本発明のストロンチウムを含む赤色蛍光体の製造方法について説明する。なお、以下に説明する実施例は、本技術の代表的な実施例の一例を示したものであり、これにより本技術の範囲が狭く解釈されることはない。
本説明は、水素含有濃度が異なる窒化ストロンチウムを原料とし用いた、実施例及び比較例の赤色蛍光体を製造する方法の説明でもあり、得られた赤色蛍光体の特性評価により、水素含率が５００ｐｐｍ以下である窒化ストロンチウムを用いた赤色蛍光体の製造方法を評価したものであり、それと同時に、水素含有率が５００ｐｐｍ以下である、赤色蛍光体の原料である窒化ストロンチウムを評価したものである。 Hereinafter, a method for producing a red phosphor containing strontium according to the present invention will be described with reference to Examples and Comparative Examples. In addition, the Example described below shows an example of a typical example of the present technology, and the scope of the present technology is not interpreted narrowly.
This explanation is also an explanation of the method for producing red phosphors of Examples and Comparative Examples using strontium nitride having different hydrogen content as a raw material, and the hydrogen content is determined by the characteristic evaluation of the obtained red phosphors. This is an evaluation of a method for producing a red phosphor using strontium nitride of 500 ppm or less, and at the same time, an evaluation of strontium nitride which is a raw material for a red phosphor having a hydrogen content of 500 ppm or less.
本説明は、水素含有濃度が異なる窒化ストロンチウムを原料とし用いた、実施例及び比較例の赤色蛍光体を製造する方法の説明でもあり、得られた赤色蛍光体の特性評価により、水素含率が５００ｐｐｍ以下である窒化ストロンチウムを用いた赤色蛍光体の製造方法を評価したものであり、それと同時に、水素含有率が５００ｐｐｍ以下である、赤色蛍光体の原料である窒化ストロンチウムを評価したものである。 Hereinafter, a method for producing a red phosphor containing strontium according to the present invention will be described with reference to Examples and Comparative Examples. In addition, the Example described below shows an example of a typical example of the present technology, and the scope of the present technology is not interpreted narrowly.
This explanation is also an explanation of the method for producing red phosphors of Examples and Comparative Examples using strontium nitride having different hydrogen content as a raw material, and the hydrogen content is determined by the characteristic evaluation of the obtained red phosphors. This is an evaluation of a method for producing a red phosphor using strontium nitride of 500 ppm or less, and at the same time, an evaluation of strontium nitride which is a raw material for a red phosphor having a hydrogen content of 500 ppm or less.
（実施例１）
＜窒化ストロンチウムの製造＞
金属ストロンチウム（Ｓｔｒｅｍ Ｃｈｅｍｉｃａｌｓ Ｉｎｃ．製、３８－００７４グレード、純度９９．９％）を耐圧容器内に入れ、真空排気した後、水素を充填し、１５０℃で１２時間加熱することにより水素化処理した。得られた水素化ストロンチウムを管状炉内にセットし、さらに窒素ガスを管状炉内に流しながら７００℃で３時間加熱して、前記水素化ストロンチウムを窒化処理した。得られた窒素ストロンチウムを回収し、目開き２９０μｍの篩を通ったものだけを分級選別して、赤色蛍光体の原料とする実施例１の赤色蛍光体の製造方法に用いる窒化ストロンチウム（以下、原料窒化ストロンチウムという）を得た。 Example 1
<Manufacture of strontium nitride>
Metal strontium (made by Strem Chemicals Inc., 38-0074 grade, purity 99.9%) was placed in a pressure vessel, evacuated, filled with hydrogen, and heated at 150 ° C. for 12 hours for hydrogenation. . The obtained strontium hydride was set in a tubular furnace, and further heated at 700 ° C. for 3 hours while flowing nitrogen gas into the tubular furnace to nitride the strontium hydride. The obtained nitrogen strontium is recovered, and only those that have passed through a sieve having a mesh opening of 290 μm are classified and selected, and used as the red phosphor raw material. Obtained strontium nitride).
＜窒化ストロンチウムの製造＞
金属ストロンチウム（Ｓｔｒｅｍ Ｃｈｅｍｉｃａｌｓ Ｉｎｃ．製、３８－００７４グレード、純度９９．９％）を耐圧容器内に入れ、真空排気した後、水素を充填し、１５０℃で１２時間加熱することにより水素化処理した。得られた水素化ストロンチウムを管状炉内にセットし、さらに窒素ガスを管状炉内に流しながら７００℃で３時間加熱して、前記水素化ストロンチウムを窒化処理した。得られた窒素ストロンチウムを回収し、目開き２９０μｍの篩を通ったものだけを分級選別して、赤色蛍光体の原料とする実施例１の赤色蛍光体の製造方法に用いる窒化ストロンチウム（以下、原料窒化ストロンチウムという）を得た。 Example 1
<Manufacture of strontium nitride>
Metal strontium (made by Strem Chemicals Inc., 38-0074 grade, purity 99.9%) was placed in a pressure vessel, evacuated, filled with hydrogen, and heated at 150 ° C. for 12 hours for hydrogenation. . The obtained strontium hydride was set in a tubular furnace, and further heated at 700 ° C. for 3 hours while flowing nitrogen gas into the tubular furnace to nitride the strontium hydride. The obtained nitrogen strontium is recovered, and only those that have passed through a sieve having a mesh opening of 290 μm are classified and selected, and used as the red phosphor raw material. Obtained strontium nitride).
＜結晶相の分析＞
前記原料窒化ストロンチウムについて、Ｘ線回折装置（株式会社リガク製ＵｌｔｉｍａＩＶ）を用いて、ＣｕＫα線による粉末Ｘ線回折を行った。得られたＸ線回折パターンを図１に示す。図１に示すＸ線回折パターンを、ＪＣＰＤＳカードと照合したところ、窒化ストロンチウム（Ｓｒ３Ｎ２）が生成されていることが確認された。 <Analysis of crystal phase>
The raw material strontium nitride was subjected to powder X-ray diffraction using CuKα rays using an X-ray diffractometer (Ultima IV manufactured by Rigaku Corporation). The obtained X-ray diffraction pattern is shown in FIG. When the X-ray diffraction pattern shown in FIG. 1 was collated with a JCPDS card, it was confirmed that strontium nitride (Sr 3 N 2 ) was generated.
前記原料窒化ストロンチウムについて、Ｘ線回折装置（株式会社リガク製ＵｌｔｉｍａＩＶ）を用いて、ＣｕＫα線による粉末Ｘ線回折を行った。得られたＸ線回折パターンを図１に示す。図１に示すＸ線回折パターンを、ＪＣＰＤＳカードと照合したところ、窒化ストロンチウム（Ｓｒ３Ｎ２）が生成されていることが確認された。 <Analysis of crystal phase>
The raw material strontium nitride was subjected to powder X-ray diffraction using CuKα rays using an X-ray diffractometer (Ultima IV manufactured by Rigaku Corporation). The obtained X-ray diffraction pattern is shown in FIG. When the X-ray diffraction pattern shown in FIG. 1 was collated with a JCPDS card, it was confirmed that strontium nitride (Sr 3 N 2 ) was generated.
＜水素含有量の分析＞
前記原料窒化ストロンチウムについて、無機元素分析装置（ＬＥＣＯ製ＴＣＨ－６００）を用いて、水素含有率を測定した。その結果、４８０ｐｐｍの水素が含まれていた。この結果は表１に示した。 <Analysis of hydrogen content>
For the raw material strontium nitride, the hydrogen content was measured using an inorganic element analyzer (TCH-600 manufactured by LECO). As a result, 480 ppm of hydrogen was contained. The results are shown in Table 1.
前記原料窒化ストロンチウムについて、無機元素分析装置（ＬＥＣＯ製ＴＣＨ－６００）を用いて、水素含有率を測定した。その結果、４８０ｐｐｍの水素が含まれていた。この結果は表１に示した。 <Analysis of hydrogen content>
For the raw material strontium nitride, the hydrogen content was measured using an inorganic element analyzer (TCH-600 manufactured by LECO). As a result, 480 ppm of hydrogen was contained. The results are shown in Table 1.
（実施例２～４、比較例１～３）
窒化処理の加熱温度、加熱時間を変更して行った以外は実施例１と同様の方法を持って、実施例２～４及び比較例１～３の原料窒化ストロンチウムを得た。これらの水素含有率の結果は、実施例１と併せて表１に示した。 (Examples 2 to 4, Comparative Examples 1 to 3)
The raw material strontium nitride of Examples 2 to 4 and Comparative Examples 1 to 3 was obtained in the same manner as in Example 1 except that the heating temperature and heating time of the nitriding treatment were changed. The results of these hydrogen contents are shown in Table 1 together with Example 1.
窒化処理の加熱温度、加熱時間を変更して行った以外は実施例１と同様の方法を持って、実施例２～４及び比較例１～３の原料窒化ストロンチウムを得た。これらの水素含有率の結果は、実施例１と併せて表１に示した。 (Examples 2 to 4, Comparative Examples 1 to 3)
The raw material strontium nitride of Examples 2 to 4 and Comparative Examples 1 to 3 was obtained in the same manner as in Example 1 except that the heating temperature and heating time of the nitriding treatment were changed. The results of these hydrogen contents are shown in Table 1 together with Example 1.
（実施例５）
＜赤色蛍光体の製造＞
赤色蛍光体の原料としてのα型窒化ケイ素粉末（宇部興産株式会社製ＳＮ－Ｅ１０グレード、酸素含有率１．０ｍａｓｓ％）５２．２ｍａｓｓ％、窒化アルミニウム粉末（トクヤマ株式会社製Ｅグレード、酸素含有率０．８ｍａｓｓ％）４５．８ｍａｓｓ％、酸化ユーロピウム（信越化学工業株式会社製ＲＵグレード）２．０ｍａｓｓ％を、ナイロン製ポットと窒化ケイ素製ボールを使用し溶媒としてエタノールを使用して、ボールミル混合を行った。溶媒を乾燥除去後、目開き７５μｍの篩を通ったものだけに分級選別して、凝集物を取り除いた中間原料混合物を得た。 (Example 5)
<Manufacture of red phosphor>
Α-type silicon nitride powder (SN-E10 grade, Ube Industries, Ltd., oxygen content 1.0 mass%) 52.2 mass%, aluminum nitride powder (E grade, Tokuyama Corp., oxygen content) 0.8 mass%) 45.8 mass%, europium oxide (RU grade made by Shin-Etsu Chemical Co., Ltd.) 2.0 mass%, using a nylon pot and silicon nitride balls, and ethanol as a solvent, mixing the ball mill went. After removing the solvent by drying, it was classified and sorted only through a sieve having an opening of 75 μm to obtain an intermediate raw material mixture from which aggregates had been removed.
＜赤色蛍光体の製造＞
赤色蛍光体の原料としてのα型窒化ケイ素粉末（宇部興産株式会社製ＳＮ－Ｅ１０グレード、酸素含有率１．０ｍａｓｓ％）５２．２ｍａｓｓ％、窒化アルミニウム粉末（トクヤマ株式会社製Ｅグレード、酸素含有率０．８ｍａｓｓ％）４５．８ｍａｓｓ％、酸化ユーロピウム（信越化学工業株式会社製ＲＵグレード）２．０ｍａｓｓ％を、ナイロン製ポットと窒化ケイ素製ボールを使用し溶媒としてエタノールを使用して、ボールミル混合を行った。溶媒を乾燥除去後、目開き７５μｍの篩を通ったものだけに分級選別して、凝集物を取り除いた中間原料混合物を得た。 (Example 5)
<Manufacture of red phosphor>
Α-type silicon nitride powder (SN-E10 grade, Ube Industries, Ltd., oxygen content 1.0 mass%) 52.2 mass%, aluminum nitride powder (E grade, Tokuyama Corp., oxygen content) 0.8 mass%) 45.8 mass%, europium oxide (RU grade made by Shin-Etsu Chemical Co., Ltd.) 2.0 mass%, using a nylon pot and silicon nitride balls, and ethanol as a solvent, mixing the ball mill went. After removing the solvent by drying, it was classified and sorted only through a sieve having an opening of 75 μm to obtain an intermediate raw material mixture from which aggregates had been removed.
前記中間原料混合物と、先に示した水素含有率４８０ｐｐｍの原料窒化ストロンチウム、及び、窒化カルシウム粉末（Ｍａｔｅｒｉｏｎ社製、純度９９％、粒径７５μｍ以下、酸素含有率０．６ｍａｓｓ％）を、雰囲気を窒素置換したグローブボックス内に搬入し、Ｓｒ／（Ｓｒ＋Ｃａ）比が０．９０になるように、中間原料混合物：原料窒化ストロンチウム：窒化カルシウム＝４９．５ｍａｓｓ％：４８．３ｍａｓｓ％：２．２ｍａｓｓ％の割合で、さらに乳鉢により混合して最終の原料混合物を得た。
The intermediate raw material mixture, the raw material strontium nitride having a hydrogen content of 480 ppm shown above, and calcium nitride powder (manufactured by Materion, purity 99%, particle size of 75 μm or less, oxygen content 0.6 mass%) are added to the atmosphere. It is carried into a nitrogen-substituted glove box, and the intermediate raw material mixture: raw material strontium nitride: calcium nitride = 49.5 mass%: 48.3 mass%: 2.2 mass% so that the Sr / (Sr + Ca) ratio is 0.90. The final raw material mixture was obtained by further mixing with a mortar.
前記原料混合物を、グローブボックス内で蓋付きの円筒型窒化ホウ素製容器（電気化学工業株式会社製Ｎ－１グレード）に充填し、グローブボックスから取り出し、カーボンヒーターの電気炉内に速やかにセットし、電気炉内を０．１Ｐａ以下まで十分に真空排気した。真空排気したまま加熱を開始し、６００℃到達後から窒素ガスを電気炉内に導入し、炉内雰囲気圧力を０．９ＭＰａとした。窒素ガス導入後もそのまま１８００℃まで昇温し、１８００℃で４時間の焼成を行った。
The raw material mixture is filled in a cylindrical boron nitride container (N-1 grade, manufactured by Denki Kagaku Kogyo Co., Ltd.) with a lid in the glove box, taken out from the glove box, and immediately set in the electric furnace of the carbon heater. The inside of the electric furnace was sufficiently evacuated to 0.1 Pa or less. Heating was started with evacuation, and after reaching 600 ° C., nitrogen gas was introduced into the electric furnace, and the atmospheric pressure in the furnace was set to 0.9 MPa. After the introduction of nitrogen gas, the temperature was raised to 1800 ° C. as it was, and firing was performed at 1800 ° C. for 4 hours.
電気炉への通電を止めて常温にまで冷却した後、ボールミルを用いて焼成物を解砕し、さらに目開き４５μｍの振動篩により分級した。
After stopping energization of the electric furnace and cooling to room temperature, the fired product was crushed using a ball mill and further classified with a vibrating sieve having an opening of 45 μm.
分級後の焼成物に対して、Ｘ線回折装置（株式会社リガク製ＵｌｔｉｍａＩＶ）を用い、ＣｕＫα線を用いた粉末Ｘ線回折を行った。得られたＸ線回折パターンは、（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相と同一の回折パターンであり、従って、前記焼成物の主結晶相が（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相としており、前記焼成物はストロンチウムを含む赤色蛍光体であることが確認された。
The fired product after classification was subjected to powder X-ray diffraction using CuKα rays using an X-ray diffractometer (Uriga IV manufactured by Rigaku Corporation). The resulting X-ray diffraction pattern, (Sr, Ca) AlSiN 3 have the same crystalline phase same diffraction as pattern and, therefore, the main crystal phase of the baked product (Sr, Ca) AlSiN 3 identical crystal and It was confirmed that the phase was a host crystal phase, and the fired product was a red phosphor containing strontium.
得られた赤色蛍光体中に含まれるＣａ、Ｓｒ量は、加圧酸分解法により前記焼成物を溶解させた後、ＩＣＰ発光分光分析装置（株式会社リガク製、ＣＩＲＯＳ－１２０）を用いて測定した。その結果、この焼成物中のＳｒ／（Ｃａ＋Ｓｒ）は０．９０（モル比）であった。
The amount of Ca and Sr contained in the obtained red phosphor is measured using an ICP emission spectroscopic analyzer (CIROS-120, manufactured by Rigaku Corporation) after dissolving the fired product by a pressure acid decomposition method. did. As a result, Sr / (Ca + Sr) in the fired product was 0.90 (molar ratio).
（蛍光体特性）
得られた実施例１の赤色蛍光体の蛍光スペクトルは、ローダミンＢと副標準光源により補正を行った分光蛍光光度計（日立ハイテクノロジーズ社製、Ｆ－７０００）を用いて行った。測定には、光度計に付属の固体試料ホルダーを使用し、励起波長４５５ｎｍでの蛍光スペクトルを求めた。蛍光スペクトルのピーク波長は６３０ｎｍであった。この結果は、表２に示した。なお、表２の発光強度は、蛍光スペクトルのピーク強度を指標とし、以下の実施例、比較例においては、実施例５と全く同じサンプリング方法及び条件でピーク強度を測定し、実施例５を１００％とした場合の相対値とし、１００％以上であれば良好な輝度を有すると判定した。 (Phosphor properties)
The fluorescence spectrum of the red phosphor obtained in Example 1 was measured using a spectrofluorometer (F-7000, manufactured by Hitachi High-Technologies Corporation) corrected with rhodamine B and a sub-standard light source. For the measurement, a solid sample holder attached to the photometer was used, and a fluorescence spectrum at an excitation wavelength of 455 nm was obtained. The peak wavelength of the fluorescence spectrum was 630 nm. The results are shown in Table 2. The emission intensity in Table 2 was measured using the peak intensity of the fluorescence spectrum as an index. In the following examples and comparative examples, the peak intensity was measured using the same sampling method and conditions as in Example 5, and Example 5 was set to 100. % As a relative value, and when it was 100% or more, it was determined that the product had good luminance.
得られた実施例１の赤色蛍光体の蛍光スペクトルは、ローダミンＢと副標準光源により補正を行った分光蛍光光度計（日立ハイテクノロジーズ社製、Ｆ－７０００）を用いて行った。測定には、光度計に付属の固体試料ホルダーを使用し、励起波長４５５ｎｍでの蛍光スペクトルを求めた。蛍光スペクトルのピーク波長は６３０ｎｍであった。この結果は、表２に示した。なお、表２の発光強度は、蛍光スペクトルのピーク強度を指標とし、以下の実施例、比較例においては、実施例５と全く同じサンプリング方法及び条件でピーク強度を測定し、実施例５を１００％とした場合の相対値とし、１００％以上であれば良好な輝度を有すると判定した。 (Phosphor properties)
The fluorescence spectrum of the red phosphor obtained in Example 1 was measured using a spectrofluorometer (F-7000, manufactured by Hitachi High-Technologies Corporation) corrected with rhodamine B and a sub-standard light source. For the measurement, a solid sample holder attached to the photometer was used, and a fluorescence spectrum at an excitation wavelength of 455 nm was obtained. The peak wavelength of the fluorescence spectrum was 630 nm. The results are shown in Table 2. The emission intensity in Table 2 was measured using the peak intensity of the fluorescence spectrum as an index. In the following examples and comparative examples, the peak intensity was measured using the same sampling method and conditions as in Example 5, and Example 5 was set to 100. % As a relative value, and when it was 100% or more, it was determined that the product had good luminance.
（実施例６～８、比較例４～６）
原料窒化ストロンチウムを、それぞれ実施例２～４、比較例１～３で製造した窒化ストロンチウムに変更した以外は、実施例５と同じ方法にて実施例６～８、比較例４～６の赤色蛍光体を作製した。また実施例５と同じ方法にて、実施例６～８、比較例４～６の赤色蛍光体を測定し、実施例５の結果と併せて表２に示した。 (Examples 6 to 8, Comparative Examples 4 to 6)
The red fluorescence of Examples 6 to 8 and Comparative Examples 4 to 6 was the same as that of Example 5 except that the raw material strontium nitride was changed to strontium nitride produced in Examples 2 to 4 and Comparative Examples 1 to 3, respectively. The body was made. Further, the red phosphors of Examples 6 to 8 and Comparative Examples 4 to 6 were measured by the same method as that of Example 5, and are shown in Table 2 together with the results of Example 5.
原料窒化ストロンチウムを、それぞれ実施例２～４、比較例１～３で製造した窒化ストロンチウムに変更した以外は、実施例５と同じ方法にて実施例６～８、比較例４～６の赤色蛍光体を作製した。また実施例５と同じ方法にて、実施例６～８、比較例４～６の赤色蛍光体を測定し、実施例５の結果と併せて表２に示した。 (Examples 6 to 8, Comparative Examples 4 to 6)
The red fluorescence of Examples 6 to 8 and Comparative Examples 4 to 6 was the same as that of Example 5 except that the raw material strontium nitride was changed to strontium nitride produced in Examples 2 to 4 and Comparative Examples 1 to 3, respectively. The body was made. Further, the red phosphors of Examples 6 to 8 and Comparative Examples 4 to 6 were measured by the same method as that of Example 5, and are shown in Table 2 together with the results of Example 5.
（実施例９）
Ｓｒ／（Ｓｒ＋Ｃａ）比が０．７５となるように原料比を変更した以外は実施例５と同じ方法にて実施例９の赤色蛍光体を作製した。発光強度は実施例５を１００％としたときの相対値とした。その結果は、表３に示した。 Example 9
A red phosphor of Example 9 was produced in the same manner as in Example 5 except that the raw material ratio was changed so that the Sr / (Sr + Ca) ratio was 0.75. The emission intensity was a relative value when Example 5 was taken as 100%. The results are shown in Table 3.
Ｓｒ／（Ｓｒ＋Ｃａ）比が０．７５となるように原料比を変更した以外は実施例５と同じ方法にて実施例９の赤色蛍光体を作製した。発光強度は実施例５を１００％としたときの相対値とした。その結果は、表３に示した。 Example 9
A red phosphor of Example 9 was produced in the same manner as in Example 5 except that the raw material ratio was changed so that the Sr / (Sr + Ca) ratio was 0.75. The emission intensity was a relative value when Example 5 was taken as 100%. The results are shown in Table 3.
（実施例１０、比較例７、８）
窒化ストロンチウムをそれぞれ実施例３、比較例１、２で準備した原料窒化ストロンチウムに変更した以外は、実施例９と同じ方法にて実施例１０、比較例７、８の赤色蛍光体を作製した。発光強度は実施例９を１００％としたときの相対値とした。その結果は、実施例９の結果と併せて表３に示した。 (Example 10, Comparative Examples 7 and 8)
The red phosphors of Example 10 and Comparative Examples 7 and 8 were produced in the same manner as Example 9 except that the strontium nitride was changed to the raw material strontium nitride prepared in Example 3 and Comparative Examples 1 and 2, respectively. The emission intensity was a relative value when Example 9 was 100%. The results are shown in Table 3 together with the results of Example 9.
窒化ストロンチウムをそれぞれ実施例３、比較例１、２で準備した原料窒化ストロンチウムに変更した以外は、実施例９と同じ方法にて実施例１０、比較例７、８の赤色蛍光体を作製した。発光強度は実施例９を１００％としたときの相対値とした。その結果は、実施例９の結果と併せて表３に示した。 (Example 10, Comparative Examples 7 and 8)
The red phosphors of Example 10 and Comparative Examples 7 and 8 were produced in the same manner as Example 9 except that the strontium nitride was changed to the raw material strontium nitride prepared in Example 3 and Comparative Examples 1 and 2, respectively. The emission intensity was a relative value when Example 9 was 100%. The results are shown in Table 3 together with the results of Example 9.
（実施例１１）
Ｓｒ／（Ｓｒ＋Ｃａ）比が０．４０となるように原料比を変更した以外は実施例５と同じ方法にて実施例１１の赤色蛍光体を作製した。 (Example 11)
A red phosphor of Example 11 was produced in the same manner as in Example 5 except that the raw material ratio was changed so that the Sr / (Sr + Ca) ratio was 0.40.
Ｓｒ／（Ｓｒ＋Ｃａ）比が０．４０となるように原料比を変更した以外は実施例５と同じ方法にて実施例１１の赤色蛍光体を作製した。 (Example 11)
A red phosphor of Example 11 was produced in the same manner as in Example 5 except that the raw material ratio was changed so that the Sr / (Sr + Ca) ratio was 0.40.
（実施例１２、比較例９、１０）
原料窒化ストロンチウムをそれぞれ実施例３、比較例１、２で準備した原料窒化ストロンチウムに変更した以外は、実施例１１と同じ方法にて実施例１２、比較例９、１０の蛍光体粉末を作製した。発光強度は実施例１１を１００％としたときの相対値とした。その結果は、実施例１１の結果と併せて表４に示した。 (Example 12, Comparative Examples 9, 10)
The phosphor powders of Example 12 and Comparative Examples 9 and 10 were produced in the same manner as Example 11 except that the raw material strontium was changed to the raw material strontium nitride prepared in Example 3 and Comparative Examples 1 and 2, respectively. . The emission intensity was a relative value when Example 11 was 100%. The results are shown in Table 4 together with the results of Example 11.
原料窒化ストロンチウムをそれぞれ実施例３、比較例１、２で準備した原料窒化ストロンチウムに変更した以外は、実施例１１と同じ方法にて実施例１２、比較例９、１０の蛍光体粉末を作製した。発光強度は実施例１１を１００％としたときの相対値とした。その結果は、実施例１１の結果と併せて表４に示した。 (Example 12, Comparative Examples 9, 10)
The phosphor powders of Example 12 and Comparative Examples 9 and 10 were produced in the same manner as Example 11 except that the raw material strontium was changed to the raw material strontium nitride prepared in Example 3 and Comparative Examples 1 and 2, respectively. . The emission intensity was a relative value when Example 11 was 100%. The results are shown in Table 4 together with the results of Example 11.
表２～４に示されるように、原料の窒化ストロンチウム中の水素含有率が５００ｐｐｍ以上になると発光強度が大きく低下した。このことからストロンチウムを含む赤色蛍光体の、原料窒化ストロンチウム中の水素含有率を５００ｐｐｍ以下とすることにより、ストロンチウムを含む赤色蛍光体の輝度が向上することが分かった。
As shown in Tables 2 to 4, when the hydrogen content in the raw material strontium nitride was 500 ppm or more, the emission intensity was greatly reduced. From this, it was found that the brightness of the red phosphor containing strontium was improved by setting the hydrogen content of the red phosphor containing strontium to 500 ppm or less in the raw material strontium nitride.
以上、本発明を実施例に基づいて説明した。この実施例はあくまで例示であり、種々の変形例が可能なこと、またそうした変形例も本発明の範囲にあることは当業者に理解されるところである。
In the above, this invention was demonstrated based on the Example. It is to be understood by those skilled in the art that this embodiment is merely an example, and that various modifications are possible and that such modifications are within the scope of the present invention.
本発明のストロンチウムを含む赤色蛍光体の製造方法により得られる赤色蛍光体、例えば（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶とする蛍光体は、青色光により励起され、高輝度の赤色発光を示すことから、青色光を光源とする白色ＬＥＤ用蛍光体として好適に使用できるものであり、照明器具、画像表示装置などの発光装置に好適に使用できる。
A red phosphor obtained by the method for producing a red phosphor containing strontium according to the present invention, for example, a phosphor having the same crystal phase as (Sr, Ca) AlSiN 3 as a host crystal, is excited by blue light and has a high luminance. Since it emits red light, it can be suitably used as a phosphor for white LEDs using blue light as a light source, and can be suitably used for light-emitting devices such as lighting fixtures and image display devices.
Claims (6)
- 水素含有率が５００ｐｐｍ以下である窒化ストロンチウムを原料として用い、当該窒化ストロンチウムを含む原料混合物を焼成する焼成工程を有する、ストロンチウムを含む赤色蛍光体の製造方法。 A method for producing a red phosphor containing strontium, comprising using a strontium nitride having a hydrogen content of 500 ppm or less as a raw material and firing a raw material mixture containing the strontium nitride.
- 水素含有率が５００ｐｐｍ以下である窒化ストロンチウムを原料として用い、複数の原料を混合する混合工程と、混合工程後の原料混合物を焼成する焼成工程を有する、請求項１記載の赤色蛍光体の製造方法。 The method for producing a red phosphor according to claim 1, comprising: a mixing step of mixing a plurality of raw materials using a strontium nitride having a hydrogen content of 500 ppm or less as a raw material; .
- 水素含有率が５００ｐｐｍ以下である窒化ストロンチウムが、金属ストロンチウムと水素とを反応させて得た水素化ストロンチウムと、窒素とを反応させたものである、請求項１または２記載の赤色蛍光体の製造方法。 The red phosphor according to claim 1 or 2, wherein the strontium nitride having a hydrogen content of 500 ppm or less is obtained by reacting strontium hydride obtained by reacting metal strontium with hydrogen and nitrogen. Method.
- 窒化ストロンチウムの水素含有率が１５ｐｐｍ以上である、請求項１～３のいずれか一項記載の赤色蛍光体の製造方法。 The method for producing a red phosphor according to any one of claims 1 to 3, wherein the hydrogen content of strontium nitride is 15 ppm or more.
- ストロンチウムを含む赤色蛍光体が、（Ｓｒ，Ｃａ）ＡｌＳｉＮ３と同一の結晶相を母体結晶相とする赤色蛍光体である、請求項１～４いずれか一項記載の赤色蛍光体の製造方法。 5. The method for producing a red phosphor according to claim 1, wherein the red phosphor containing strontium is a red phosphor having the same crystal phase as (Sr, Ca) AlSiN 3 as a host crystal phase.
- 前記原料混合物は少なくとも窒化ストロンチウムと窒化カルシウムを含むものであり、当該原料混合物におけるＳｒ／（Ｃａ＋Ｓｒ）＝０．３５～０．９５（モル数比）である、請求項１～５のいずれか一項記載の赤色蛍光体の製造方法。
The raw material mixture contains at least strontium nitride and calcium nitride, and Sr / (Ca + Sr) = 0.35 to 0.95 (molar ratio) in the raw material mixture. The manufacturing method of the red fluorescent substance of description.
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| CN111902517A (en) * | 2018-03-28 | 2020-11-06 | 电化株式会社 | Phosphor, method for producing same, and light-emitting device |
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