JP2011089004A - Phosphor material and method for producing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a phosphor material that exhibits strong emission of light in an ultraviolet region by irradiation from an excitation source with a wavelength of 172 nm radiated by rare gas discharge as the excitation source of the phosphor. <P>SOLUTION: This phosphor material includes a calcium oxide-compounding oxide particle which contains yttrium oxide, wherein a molar ratio of a Y element to a Ca element in the calcium-compounding oxide particle ((Y element/Ca element)&times;100) is preferably 0.0001-10 mol% in terms of atom. <P>COPYRIGHT: (C)2011,JPO&amp;INPIT

Description

  The present invention relates to a phosphor material based on calcium oxide that emits light using vacuum ultraviolet light as an excitation source, and a method for producing the same.

  In recent years, light-emitting devices using short-wavelength vacuum ultraviolet rays emitted by rare gas discharge as an excitation source of a phosphor have been developed. In such a light emitting device, a vacuum ultraviolet excitation phosphor that emits light using vacuum ultraviolet light as an excitation source is used. A plasma display panel (PDP) is known as a display device using a vacuum ultraviolet-excited light emitting device.

  As a device for obtaining light emission by exciting a phosphor with vacuum ultraviolet light, a rare gas discharge lamp using discharge light emission by a rare gas such as xenon is also known. Rare gas discharge lamps such as xenon discharge lamps have been used for applications requiring safety, such as backlights for in-vehicle liquid crystal displays, instead of conventional mercury (Hg) discharge lamps. .

  The vacuum ultraviolet excitation type light-emitting device uses vacuum ultraviolet rays having a wavelength of 147 nm, 172 nm, etc. emitted by a rare gas discharge instead of the conventional ultraviolet rays from an electron beam or mercury as a phosphor excitation source.

  As a vacuum excitation type phosphor for PDP, for example, it has been proposed to use an MgO-based phosphor having a characteristic of performing cathodoluminescence having an emission peak in the near ultraviolet region by being excited by vacuum ultraviolet rays ( For example, see Patent Document 1.)

  Patent Document 2 proposes a phosphor material obtained by mixing calcium carbonate, yttrium oxide, europium oxide, gallium oxide and indium oxide, and subjecting the mixture to a heat treatment at a temperature of about 1300 ° C.

JP 2008-166039 A (Claims) JP 2000-34479 A (page 6, paragraph 0035)

  In the phosphor materials of Patent Document 1 and Patent Document 2, light emission is observed in the near-ultraviolet region by irradiation of an excitation source having a wavelength of 172 nm emitted by a rare gas discharge as an excitation source of the phosphor. It was low.

  Accordingly, an object of the present invention is to provide a phosphor material that exhibits strong light emission in the ultraviolet region when irradiated with an excitation source having a wavelength of 172 nm emitted by a rare gas discharge as an excitation source of the phosphor.

  As a result of intensive studies to solve such problems, the present inventors have coated the surface of the calcium oxide precursor particles converted to calcium oxide by thermal decomposition with a precursor of yttrium oxide serving as an activator element. Then, the resulting coated processed product is heat-treated and thermally decomposed to obtain calcium oxide composite oxide particles containing yttrium oxide, and the calcium oxide composite oxide serves as a noble gas as an excitation source. The inventors have found that when a wavelength of 172 nm emitted by electric discharge is used, there is a strong emission peak in a specific ultraviolet region, and the present invention has been completed.

  That is, the present invention (1) provides a phosphor material characterized in that it is calcium oxide composite oxide particles containing yttrium oxide.

  Further, the present invention (2) is a coating treatment product in which the surface of calcium oxide precursor particles converted into calcium oxide particles by thermal decomposition is coated with an yttrium oxide precursor converted into yttrium oxide by thermal decomposition. The present invention provides a phosphor material obtained by performing a heat treatment step of obtaining calcium oxide composite oxide particles containing yttrium oxide by heat treatment and thermal decomposition.

In the present invention (3), a Y element source is added to an aqueous slurry in which calcium oxide precursor particles converted into calcium oxide particles by thermal decomposition are dispersed in a dispersion medium, and then the Y element source A coating treatment step of precipitating a hydrolyzate of the Y element source on the surface of the calcium oxide precursor particles to obtain a coating treatment product,
A heat treatment step of obtaining calcium oxide composite oxide particles containing yttrium oxide by heat-treating and thermally decomposing the coated product;
A method for producing a phosphor material characterized by comprising:

  ADVANTAGE OF THE INVENTION According to this invention, the phosphor material which shows strong light emission in an ultraviolet region can be provided by irradiation of the excitation source of wavelength 172nm radiated | emitted by rare gas discharge as a phosphor excitation source.

It is typical sectional drawing of an aggregate (B). It is typical sectional drawing of the aggregate (C) which the calcium oxide precursor particle aggregated. 3 is an X-ray diffraction diagram of the phosphor material obtained in Reference Example 1. FIG. 6 is an X-ray diffraction diagram of a phosphor material obtained in Reference Example 2. FIG. 2 is an SEM photograph (magnification 1,000) of the phosphor material obtained in Example 1. 2 is an SEM photograph (magnification 10,000) of the phosphor material obtained in Example 1. 3 is an SEM photograph (magnification 1,000) of the phosphor material obtained in Comparative Example 1. 2 is an SEM photograph (magnification 10,000) of the phosphor material obtained in Comparative Example 1. It is a fluorescence spectrum figure of the phosphor material obtained in Examples 1-6 and Comparative Examples 1 and 2.

  In the phosphor material of the present invention, first, an aqueous slurry is prepared by dispersing calcium oxide precursor particles in a dispersion medium, a Y element source is added to the aqueous slurry, and then the Y element source is hydrolyzed. As a result, a hydrolyzate of the Y element source adheres to the surface of the calcium oxide precursor particles, and a coated processed product is obtained in which the surface of the calcium oxide precursor particles is coated with the hydrolyzate of the Y element source. It is done.

  Next, by subjecting the coating treatment to heat treatment and thermal decomposition, the calcium oxide precursor particles are converted into calcium oxide particles, and the hydrolyzate of the Y element source is converted into fine particles of yttrium oxide. By continuing the heat treatment, calcium oxide composite oxide particles containing yttrium oxide can be obtained. This calcium oxide composite oxide particle containing yttrium oxide is a composite oxide composed of yttrium oxide and calcium oxide, and is a composite oxide obtained by doping calcium oxide with an yttrium element.

  Thus, the phosphor material of the present invention is a composite oxide particle in which calcium oxide particles as a base material contain yttrium oxide as an activator. The phosphor material obtained by the conventional method disclosed in Japanese Patent Laid-Open No. 2000-34479 is obtained by simply mixing calcium carbonate, yttrium oxide, europium oxide, gallium oxide and indium oxide uniformly, and heating the mixture at 1300 ° C. Although the body material is manufactured, what is obtained by Unexamined-Japanese-Patent No. 2000-34479 is a simple mixture, and is distinguished from the complex oxide concerning this invention.

  The phosphor material of the present invention has a maximum emission peak at 250 to 270 nm in the ultraviolet region when irradiated with an excitation source having a wavelength of 172 nm emitted by rare gas discharge as an excitation source of the phosphor. In the present invention, “having a maximum emission peak at 250 to 270 nm” means that an emission peak having a peak top at 250 to 270 nm is observed in an emission spectrum obtained by emission analysis. .

  In the calcium oxide composite oxide particles according to the phosphor material of the present invention, the molar ratio of Y element to Ca element {(Y element / Ca element)} × 100} is preferably 0.0001 to 10 mol% in terms of atoms. Especially preferably, it is 0.01-1 mol%. When the molar ratio of the Y element to the Ca element in the calcium oxide composite oxide particles is within the above range, the ultraviolet light is irradiated by the excitation source having a wavelength of 172 nm emitted by the rare gas discharge as the excitation source of the phosphor. The emission intensity increases at 250 to 270 nm in the region.

Phosphor calcium oxide composite oxide particles according to the material of the present invention, in addition to yttrium oxide, further contains an oxide of one or more elements selected from Sr and Ba (M ¹ element) As an excitation source of the phosphor, irradiation with an excitation source having a wavelength of 172 nm emitted by a rare gas discharge is preferable in that the emission intensity increases in the ultraviolet region of 250 to 270 nm. In other words, calcium composite oxide particles oxidation, in addition to yttrium, further that M ¹ element is doped, as an excitation source of the phosphor, by irradiation of an excitation source having a wavelength 172nm emitted by rare gas discharge It is preferable in that the emission intensity increases at 250 to 270 nm in the near ultraviolet region. The calcium oxide particles is, if it contains an oxide of M ¹ element, the molar ratio of M ¹ element to a total of M ¹ element and Ca element in calcium oxide composite oxide particles [{M ¹ element / (M ¹ Element + Ca element)} × 100] is preferably 50 mol% or less, and particularly preferably 0.1 to 10 mol% in terms of atoms. In the case M ¹ element is 2 or more, the molar ratio of the M ¹ element is their total.

  The average particle diameter of the calcium oxide composite oxide particles (primary particles) according to the phosphor material of the present invention is preferably 0.01 to 10 μm, particularly preferably 0.05 to 1 μm. When the average particle diameter of the primary particles is within the above range, the emission intensity is high at 250 to 270 nm in the ultraviolet region when irradiated with an excitation source having a wavelength of 172 nm emitted by a rare gas discharge as an excitation source of the phosphor. Become. In addition, the average particle diameter of the primary particles of the calcium oxide composite oxide particles is determined by observation with a scanning electron microscope (SEM). Specifically, the particle diameter of all primary particles in one field of view of the electron micrograph is obtained. Measured and averaged. On the other hand, the secondary particles of the calcium oxide composite oxide particles refer to aggregates in which the primary particles of the calcium oxide composite oxide particles are aggregated.

  The calcium oxide composite oxide particles (primary particles) according to the phosphor material of the present invention usually exist as aggregated aggregates (secondary particles). The average particle diameter D50 (average particle diameter of secondary particles) obtained by the laser diffraction scattering method of the phosphor material of the present invention is preferably 0.1 to 100 μm, particularly preferably 1 to 20 μm. The phosphor material of the present invention may be in the form of primary particles of calcium oxide composite oxide particles that are not aggregated. In the present invention, it can be specifically confirmed by scanning electron microscope observation (SEM) that the primary particles are aggregated to form secondary particles. When the phosphor material of the present invention is observed by SEM, 80% or more of one field of view is preferably aggregated particles.

  In the phosphor material of the present invention, the form of the aggregate of the calcium oxide composite oxide particles includes an aggregate in which only the calcium oxide composite oxide particles are aggregated, and a calcium oxide composite oxide around the aggregate of the calcium oxide particles. The form of the aggregate which the product particle aggregated is mentioned. Hereinafter, an aggregate formed by aggregation of only the calcium oxide composite oxide particles according to the phosphor material of the present invention is also referred to as an aggregate (A), and around the aggregate of the calcium oxide particles, The aggregate formed by aggregation of the calcium oxide composite oxide particles according to the phosphor material of the present invention is also referred to as an aggregate (B).

  The aggregate B will be described with reference to FIG. FIG. 1 is a schematic cross-sectional view of the aggregate (B). In FIG. 1, the aggregate (B) 3 is an aggregate of calcium oxide particles 1 (shown in white) inside, and the calcium oxide composite oxide according to the phosphor material of the present invention is around the aggregate. Particles 2 (indicated by oblique lines) are aggregated to form.

  The tapping density of the phosphor material of the present invention is preferably 0.30 to 0.60 g / mL, particularly preferably 0.35 to 0.55 g / mL. When the tapping density is within the above range, it is preferable from the viewpoint of excellent dispersion characteristics in a medium and mixing characteristics with other compounds.

  The phosphor material of the present invention is obtained by coating the surface of calcium oxide precursor particles, which are converted into calcium oxide particles by thermal decomposition, with a yttrium oxide precursor to obtain a coating treatment, and then heating the coating treatment Thus, calcium oxide composite oxide particles containing yttrium oxide obtained by thermal decomposition are preferable.

  The phosphor material of the present invention is preferably produced by the following method for producing the phosphor material of the present invention.

The method for producing the phosphor material of the present invention includes a coating treatment step in which a surface of calcium oxide precursor particles converted into calcium oxide particles by thermal decomposition is coated with an yttrium oxide precursor to obtain a coated product.
And a heat treatment step of obtaining a calcium oxide composite oxide particle containing yttrium oxide by heat-treating the coating-treated product and thermally decomposing the phosphor-treated material.

  The coating treatment step according to the method for producing the phosphor material of the present invention is a step of obtaining a coated treatment product in which the surface of the calcium oxide precursor particles is coated with the yttrium oxide precursor.

  As a method for performing the coating treatment step, for example, a Y element source is added to an aqueous slurry in which calcium oxide precursor particles are dispersed in a dispersion medium, and then the Y element source is hydrolyzed to thereby yield a Y element source. There is a method in which a hydrolyzate is deposited on the surface of the calcium oxide precursor particles to obtain a coated product.

  The calcium oxide precursor particles are not particularly limited as long as they are thermally decomposed and converted into calcium oxide particles by heat treatment in a subsequent heat treatment step. For example, calcium carbonate, basic carbonate Examples include inorganic compounds having low solubility such as calcium and calcium hydroxide, and calcium salts of organic acids having low solubility such as calcium citrate and calcium oxalate. Of these, calcium carbonate and calcium hydroxide are preferred from the standpoint of availability and handling. These may be used alone or in combination of two or more.

  The calcium oxide precursor particles usually exist as aggregates (secondary particles) in which the calcium oxide precursor particles (primary particles) are aggregated, and a laser of aggregates (secondary particles) of the calcium oxide precursor particles. The average particle diameter D50 obtained by the diffraction scattering method is preferably 0.1 to 100 μm, particularly preferably 1 to 20 μm. When the average particle diameter of the aggregates of the calcium oxide precursor particles is within the above range, a uniform aqueous slurry is obtained, and the characteristics of the phosphor material after the heat treatment are easily made uniform. On the other hand, when the average particle diameter of the aggregates of the calcium oxide precursor particles exceeds the above range, the dispersion characteristic tends to be low when dispersed in the medium, and when the average particle diameter is less than the above range, the viscosity of the aqueous slurry increases. Therefore, it becomes difficult to cause a uniform reaction.

  Then, an aqueous slurry containing the calcium oxide precursor particles is prepared by dispersing the calcium oxide precursor particles in a dispersion medium.

  Examples of the dispersion medium include hydrophilic media such as water, alcohols, and ketones. Of these, water is preferred because it is easy to handle. The dispersion medium is preferably purified by distillation, ion exchange treatment with an ion exchange resin, activated carbon treatment, or the like.

  In the aqueous slurry, the concentration of the calcium oxide precursor particle slurry is 1 to 20% by mass, preferably 5 to 20% by mass. When the concentration of the slurry is within the above range, adhesion of the coated product to the calcium oxide precursor particles becomes uniform and operability is improved.

  Next, a Y element source is added to the aqueous slurry. The Y element source is not particularly limited as long as it is a compound containing the Y element and can be dissolved in the dispersion medium. When the dispersion medium is water, examples include yttrium nitrate and yttrium chloride. The compound may be an anhydrous salt or may contain crystal water.

  In the aqueous slurry, the mixing ratio of the calcium oxide precursor particles and the Y element source is the molar ratio of Y element to Ca element in the coated product obtained by performing the coating process ((Y element / Ca element) × 100). However, the quantity used as 0.0001-10 mol% in conversion of an atom is preferable, and the quantity used as 0.01-1 mol% is especially preferable. When the mixing ratio of the calcium oxide precursor particles and the Y element source is within the above range, as an excitation source of the phosphor, irradiation of an excitation source having a wavelength of 172 nm emitted by a rare gas discharge results in an ultraviolet region. The emission intensity increases at 250 to 270 nm.

In addition to the Y element source, an M ¹ element source can also be added to the aqueous slurry. The M ¹ element source is not particularly limited as long as it is a compound having an M ¹ element and can be dissolved in a dispersion medium. When the dispersion medium is water, a nitrate of M ¹ element include chlorides of M ¹ element.

When adding M ¹ element source to an aqueous slurry, the aqueous slurry, the mixing ratio of the (any one or more of which of Sr and Ba) source calcium precursor particles and said M ¹ element oxide , the molar ratio of ^{M 1} element to a total of the Ca element and ^{M 1} element of the coating treated in the resulting make coat processing step ^{[{M 1} element / ^{(M 1} element + Ca element)} × 100] is, terms of atom The amount is preferably 50 mol% or less, and particularly preferably 0.1 to 10 mol%. When the mixing ratio of the calcium oxide precursor particles and the M ¹ element source is within the above range, the irradiation of the excitation source having a wavelength of 172 nm emitted by the rare gas discharge as the excitation source of the phosphor can be performed in the ultraviolet region. The emission intensity increases at 250 to 270 nm. When the number of M ¹ elements is 2 or more, the number of moles of the M ¹ element is the sum of them.

Y element source to an aqueous slurry, as an additive method M ¹ element source may be charged with these element source directly to the aqueous slurry, or solution of an aqueous slurry prepared by dissolving these element source in the dispersion medium It may be thrown into.

After adding the Y element source to the aqueous slurry, or after adding the M ¹ element source as necessary, the aqueous slurry is stirred as necessary.

Next, the Y element source in the aqueous slurry is hydrolyzed. Also, when added even M ¹ element source to an aqueous slurry also hydrolyze these element source. Then, by hydrolyzing the Y element source, a hydrolyzate of the Y element source, that is, an yttrium oxide precursor is attached to the surface of the calcium oxide precursor particles, thereby obtaining a coated product. Also, when added even M ¹ element source to an aqueous slurry in addition to Y element sources, by also hydrolyze these element source, the surface of the calcium oxide precursor particles, in addition to yttrium oxide precursor M ¹ hydrolyzate element source, i.e., a precursor also deposited the oxide of M ¹ element, to obtain a coating treated.

Examples of the method for hydrolyzing the Y element source and the M ¹ element source in the aqueous slurry include a method in which an alkali such as ammonia, amines, and alkali metal hydroxide is added to the aqueous slurry and stirred.

Y element sources, hydrolysis temperature for carrying out the hydrolysis of ^{M 1} element source, 5 to 80 ° C., preferably from 15 to 50 ° C.. When the hydrolysis temperature is within the above range, operational safety is improved, and there is an advantage that a special heat source and apparatus are not required.

  After completion of the addition of alkali, aging can be performed with continued stirring as necessary. Aging is preferable in that the hydrolyzate can be sufficiently attached to the surface of the calcium oxide precursor particles. The aging temperature at the time of aging is usually 5 to 80 ° C., preferably 15 to 50 ° C. If the aging temperature is less than the above range, hydrolysis tends to be insufficient, and if it exceeds the above range, rapid hydrolysis occurs, so that the hydrolyzate uniformly adheres to the surface of the calcium oxide precursor particles. It becomes difficult. The aging temperature refers to the temperature of the entire reaction liquid when stirring after adding an alkali. The aging time for aging is 0.5 hours or more, preferably 1 hour or more.

In addition, when the calcium oxide precursor particles are calcium carbonate or calcium hydroxide, these compounds are slightly soluble in water, so that the aqueous slurry exhibits alkalinity. In such a case, after adding the Y element source and, if necessary, the M ¹ element source to the aqueous slurry, hydrolysis can be carried out by stirring at 5 to 80 ° C., preferably 15 to 50 ° C. . In this case, hydrolysis of these element sources occurs by adding a Y element source and, if necessary, an M ¹ element source to the aqueous slurry and stirring the aqueous slurry. In such a case, after completion of the addition of the Y element source and, if necessary, the M ¹ element source, aging can be performed with continued stirring as necessary. Aging is preferable in that the hydrolyzate can sufficiently adhere to the surface of the calcium oxide precursor particles. The aging temperature at the time of aging is usually 5 to 80 ° C., preferably 15 to 50 ° C. The aging time for aging is 0.5 hours or more, preferably 1 hour or more. In addition, when calcium oxide precursor particle | grains are calcium carbonate or calcium hydroxide, it can also hydrolyze by adding an alkali to aqueous slurry and stirring.

  After completion of hydrolysis (when aging is performed if necessary), solid-liquid separation is performed by a conventional method, and then the separated solid is washed with water. The cleaning method is not particularly limited. Then, after the washing is completed, it can be dried and pulverized or the like as desired.

  Next, a heat treatment process is performed for heat-treating the coated product obtained by performing the coating process.

The heat treatment step, by heating the coating treated by thermal decomposition, thereby converting calcium oxide precursor particles to calcium oxide particles, hydrolysates of Y element sources, a hydrolyzate of M ¹ element source, these Calcium oxide composite oxide particles containing yttrium oxide are obtained by converting into the oxide fine particles of the element and further continuing the heat treatment.

  The heat treatment temperature when performing the heat treatment step is 500 ° C to 1600 ° C, preferably 650 to 1300 ° C. If the heating temperature is less than the above range, the conversion from the calcium oxide precursor to calcium oxide does not proceed. On the other hand, if the heating temperature exceeds the above range, contamination by the heat treatment container is likely to proceed, and sintering proceeds, pulverization and Secondary processing such as grinding becomes difficult. The heating time when performing the heat treatment step is 1 to 20 hours, preferably 3 to 12 hours. The atmosphere in performing the heat treatment step is not particularly limited, and may be any of an air atmosphere, an inert atmosphere, and a reducing atmosphere.

  The material of the furnace used for heating is not particularly limited, and examples thereof include silicon carbide, alumina / zirconia, high-purity alumina, spinel, mullite, cordierite, and the like. It is not limited to.

  In the heat treatment step according to the method for producing the phosphor material of the present invention, the heat treatment may be performed as many times as desired. In order to make the powder characteristics uniform, the heat treatment once is pulverized and again Heat treatment may be performed.

  After performing a heat treatment process, it cools suitably and crushes as needed to obtain a phosphor material. For crushing, a normal crushing device such as a jaw crusher, a roll mill, a jet mill, or a ball mill can be used.

In the coating treatment step, the calcium oxide precursor particles whose surface is coated are usually present as aggregates (C) 5 in which calcium oxide precursor particles 1 (shown in white) are aggregated as shown in FIG. To do. Therefore, when such an aggregate (C) 5 is dispersed in a dispersion medium and a Y element source and, if necessary, an M ¹ element source are added to hydrolyze these element sources, a calcium oxide precursor is obtained. Of the particles 1, only the surface of the calcium oxide precursor particles 1a existing near the outside of the aggregate (C) 5 is a hydrolyzate of the Y element source, and the hydrolysis of the M ¹ element source added as necessary. The surface of the calcium oxide precursor particles 1b coated with the product and present inside the aggregate (C) 5 is not coated with the hydrolyzate of these element sources.

  Therefore, the phosphor material obtained by performing the coating treatment step and the heat treatment step using such an aggregate (C) 5 is the aggregate of calcium oxide particles like the aggregate (B) 3 shown in FIG. A form in which the calcium oxide composite oxide particles 2 (primary particles) are aggregated around the aggregate, that is, an aggregate (B) 3 is obtained. If the calcium oxide composite oxide particles according to the phosphor material of the present invention are present on the surface of the phosphor material, an excitation source having a wavelength of 172 nm emitted by a rare gas discharge is used as the phosphor excitation source. Irradiation shows strong emission intensity in the ultraviolet region of 250 to 270 nm, and thus even in such a form (aggregate (B)), the effect of the present invention is exhibited.

  The phosphor material thus obtained has a maximum emission peak at 250 to 270 nm in the ultraviolet region when irradiated with an excitation source having a wavelength of 172 nm emitted by a rare gas discharge as an excitation source of the phosphor, and is high Emission intensity is shown, and it is particularly suitably used as a phosphor material for PDP.

EXAMPLES Hereinafter, although an Example demonstrates this invention in detail, this invention is not limited to these.
(Reference experiment)
(Reference Example 1)
In a 1 L glass beaker containing 500 mL of ion-exchanged water, 74.1 g (CaO: 1 mol) of commercially available calcium hydroxide (76% as CaO, average particle diameter 6 μm) was added and stirred, and an aqueous slurry of calcium hydroxide was added. Prepared. Separately, 3.03 g (Y: 0.01 mol) of yttrium chloride hexahydrate was weighed into a 100 mL glass beaker and dissolved by adding 100 mL of ion-exchanged water (solution A). Using a metering pump, solution A was dropped into an aqueous calcium hydroxide slurry at a flow rate of 1.7 mL / min. At this time, both the aqueous slurry of calcium hydroxide and the yttrium solution were carried out at 20 ° C.
After completion of the dropwise addition, the mixture was kept at 20 ° C. for 30 minutes with continuation of stirring, and aged. Subsequently, the reaction liquid was filtered with a Buchner funnel, and the solid content after filtration was dried at 120 ° C. for 12 hours to obtain a coated product. Next, this coated product was heated in an electric furnace at 1300 ° C. for 5 hours in an air atmosphere, naturally cooled, and then crushed to obtain a phosphor material sample.

(Reference Example 2)
100.1 g of commercially available calcium carbonate (CaO: 1 mol, average particle diameter: 3 μm) and 1.13 g of yttrium oxide (Y: 0.01 mol) were mixed lightly, and ethanol was added thereto and mixed in a mortar for 1 hour. . The obtained mixture was dried at 120 ° C. for 12 hours and then heated at 1300 ° C. for 3 hours to obtain a phosphor material sample.

X-ray diffraction analysis was performed using Cu—Kα rays using the phosphor material samples obtained in Reference Example 1 and Reference Example 2 as a radiation source. X-ray diffraction patterns of the phosphor material sample are shown in FIGS. 3 and 4, respectively. Incidentally, it was also shown together suit X-ray diffraction diagram measured with CaO alone and _Y 2 _{O 3} alone.
From the results of FIGS. 3 and 4, the phosphor material sample of Reference Example 1 obtains single-phase CaO, which is a complex oxide composed of CaO and Y ₂ O ₃ , whereas the fluorescence of Reference Example 2 It can be seen that the body material sample is a simple mixture of CaO and Y ₂ O ₃ because a diffraction line belonging to Y ₂ O ₃ can be confirmed at the position indicated by the arrow.
Accordingly, the phosphor material of the present invention obtained in the following examples is further reacted under the condition that the addition amount of Y is not more than the addition amount in Reference Example 1 and single-phase CaO can be easily obtained. Thus, it can be seen that the phosphor material of the present invention is a composite oxide in which calcium oxide particles contain yttrium oxide, that is, a composite oxide in which calcium oxide is doped with yttrium.

Example 1
In a 1 L glass beaker containing 500 mL of ion-exchanged water, 74.1 g (CaO: 1 mol) of commercially available calcium hydroxide (76% as CaO, average particle diameter 6 μm) was added and stirred, and an aqueous slurry of calcium hydroxide was added. Prepared. Separately, 0.303 g (Y: 0.001 mol) of yttrium chloride hexahydrate was weighed into a 100 mL glass beaker and dissolved by adding 100 mL of ion-exchanged water (solution A). Using a metering pump, solution A was dropped into an aqueous calcium hydroxide slurry at a flow rate of 1.7 mL / min. At this time, both the aqueous slurry of calcium hydroxide and the yttrium solution were carried out at 20 ° C.
After completion of the dropwise addition, the mixture was kept at 20 ° C. for 30 minutes with continuation of stirring, and aged. Subsequently, the reaction liquid was filtered with a Buchner funnel, and the solid content separated by filtration was dried at 120 ° C. for 12 hours to obtain a coated product a. Next, this coated processed product a was heated in an electric furnace at 900 ° C. for 5 hours in an air atmosphere, naturally cooled, and then crushed to obtain a phosphor material a.

(Example 2)
After obtaining the coated product a in the same manner as in Example 1, the coated product a was heated at 1300 ° C. in an air atmosphere for 5 hours, naturally cooled, and crushed to obtain a phosphor material b.

Example 3
73.4 g (CaO: 0.99 mol) of commercially available calcium hydroxide (76% as CaO, average particle size 6 μm) was added to a 1 L glass beaker containing 500 mL of ion-exchanged water and stirred to obtain an aqueous calcium hydroxide solution. A slurry was prepared. Separately, 0.303 g (Y: 0.001 mol) of yttrium chloride hexahydrate and 2.66 g (SrO: 0.01 mol) of strontium chloride hexahydrate were weighed into a 100 mL glass beaker and ion-exchanged water. 100 mL was added and dissolved to prepare a strontium yttrium solution (solution A). Using a metering pump, solution A was dropped into an aqueous calcium hydroxide slurry at a flow rate of 1.7 mL / min. Both the aqueous slurry of calcium hydroxide and the strontium yttrium solution at this time were carried out at 20 ° C.
After completion of the dropwise addition, the mixture was kept at 20 ° C. for 30 minutes with continuation of stirring and aged. Subsequently, the reaction liquid was filtered with a Buchner funnel, and the solid content separated by filtration was dried at 120 ° C. for 12 hours to obtain a coated product c. Next, the coated product c was heated in an electric furnace at 900 ° C. for 5 hours in an air atmosphere, naturally cooled, and then crushed to obtain a phosphor material c.

Example 4
73.4 g (CaO: 0.99 mol) of commercially available calcium hydroxide (76% as CaO, average particle size 6 μm) was added to a 1 L glass beaker containing 500 mL of ion-exchanged water and stirred to obtain an aqueous calcium hydroxide solution. A slurry was prepared. Separately, weigh 0.303 g (Y: 0.001 mol) of yttrium chloride hexahydrate and 2.61 g of barium nitrate (BaO: 0.01 mol) into a 100 mL glass beaker, and add 100 mL of ion-exchanged water. And dissolved into a barium yttrium solution (solution A). Using a metering pump, solution A was dropped into an aqueous calcium hydroxide slurry at a flow rate of 1.7 mL / min. Both the aqueous slurry of calcium hydroxide and the barium yttrium solution at this time were carried out at 20 ° C.
After completion of the dropwise addition, the mixture was kept at 20 ° C. for 30 minutes with continuation of stirring and aged. Next, the reaction solution was filtered with a Buchner funnel, and the solid content separated by filtration was dried at 120 ° C. for 12 hours to obtain a coated product d. Next, the coated product d was heated in an electric furnace at 900 ° C. for 5 hours in an air atmosphere, naturally cooled, and then crushed to obtain a phosphor material d.

(Example 5)
In a 1 L glass beaker containing 500 mL of ion-exchanged water, 74.1 g (CaO: 1 mol) of commercially available calcium hydroxide (76% as CaO, average particle diameter 6 μm) was added and stirred, and an aqueous slurry of calcium hydroxide was added. Prepared. Separately, 0.030 g (Y: 0.0001 mol) of yttrium chloride hexahydrate was weighed into a 100 mL glass beaker, and dissolved by adding 100 mL of ion-exchanged water (solution A). Using a metering pump, solution A was dropped into an aqueous calcium hydroxide slurry at a flow rate of 1.7 mL / min. At this time, both the aqueous slurry of calcium hydroxide and the yttrium solution were carried out at 20 ° C.
After completion of the dropwise addition, the mixture was kept at 20 ° C. for 30 minutes with continuation of stirring, and aged. Subsequently, the reaction liquid was filtered with a Buchner funnel, and the solid content separated by filtration was dried at 120 ° C. for 12 hours to obtain a coated product e. Next, this coated processed product e was heated in an electric furnace at 900 ° C. for 5 hours in an air atmosphere, naturally cooled, and then crushed to obtain a phosphor material e.

(Example 6)
In a 1 L glass beaker containing 500 mL of ion-exchanged water, 74.1 g (CaO: 1 mol) of commercially available calcium hydroxide (76% as CaO, average particle diameter 6 μm) was added and stirred, and an aqueous slurry of calcium hydroxide was added. Prepared. Separately, 3.03 g (Y: 0.01 mol) of yttrium chloride hexahydrate was weighed into a 100 mL glass beaker and dissolved by adding 100 mL of ion-exchanged water (solution A). Using a metering pump, solution A was dropped into an aqueous calcium hydroxide slurry at a flow rate of 1.7 mL / min. At this time, both the aqueous slurry of calcium hydroxide and the yttrium solution were carried out at 20 ° C.
After completion of the dropwise addition, the mixture was kept at 20 ° C. for 30 minutes with continuation of stirring, and aged. Subsequently, the reaction liquid was filtered with a Buchner funnel, and the solid content separated by filtration was dried at 120 ° C. for 12 hours to obtain a coated product f. Next, the coated product f was heated in an electric furnace at 900 ° C. for 5 hours in an air atmosphere, naturally cooled, and then crushed to obtain a phosphor material f.

Note) The average particle diameter of the calcium oxide precursor particles was determined by a laser diffraction scattering method.

(Comparative Example 1)
With reference to Japanese Patent Laid-Open No. 2000-34479, commercially available calcium carbonate (average particle size 3 μm), yttrium oxide (average particle size 8 μm), europium oxide (average particle size 5 μm), and gallium oxide (average particle size 75 μm) And aluminum oxide (average particle size 10 μm) were sufficiently mixed by dry mixing. The mixture is tightly filled into an alumina container and calcined at 1300 ° C. for 8 hours in the atmosphere. The calcined product is washed with pure water, dehydrated and dried, and Ca (Y _0.5 Eu _0.5 ) (Ga A phosphor material g having a composition of _0.5 Al _0.5 ) ₃ O ₇ was obtained.

(Comparative Example 2)
56.1 g of commercially available calcium oxide (CaO: 1 mol, average particle size 3 μm) and 0.113 g of yttrium oxide (Y: 0.001 mol, average particle size 8 μm) were mixed lightly, ethanol was added thereto, and the mixture was mortar for 1 hour. Mixed in. The obtained mixture was dried at 120 ° C. for 12 hours and then heated at 900 ° C. for 5 hours to obtain a phosphor material h.

<Evaluation of physical properties>
Table 2 shows the molar ratio (mol%) and particle size distribution of Ca element, Y element, Sr element and Ba element for the phosphor materials obtained in the examples and comparative examples. Moreover, the SEM photograph of the phosphor material a obtained in Example 1 is shown in FIGS. Further, SEM photographs of the phosphor material i obtained in Comparative Example 1 are shown in FIGS.
In calculating the molar ratio, the contents of Y, Sr, and Ba were determined by ICP emission analysis. Further, the particle size distribution of the particles was determined by a laser scattering diffraction method.

<Evaluation of fluorescence characteristics>
Fluorescence characteristics of the phosphor materials obtained in Examples 1 to 6 and Comparative Examples 1 and 2 were irradiated at 172 nm irradiated from a xenon excimer lamp from a right angle to the press-molded fluorescent complex oxide, and from the irradiated surface The emitted fluorescence was measured. The result is shown in FIG. 9, the peak top intensities between 250 and 270 nm are 22067 cps in Example 6, 7837 cps in Example 3, 6424 cps in Example 4, 5104 cps in Example 1, and 5104 cps in Example 2, in order from the top. 4011 cps, Example 5 was 1752 cps, Comparative Example 2 was 143 cps, and Comparative Example 1 was 11 cps.
From the results of FIG. 9, it was found that the phosphor materials of Examples 1 to 6 have higher emission intensity than the phosphor materials of Comparative Examples 1 and 2.

Claims (11)

  A phosphor material comprising calcium composite oxide particles containing yttrium oxide.   A phosphor material, wherein a molar ratio of Y element to Ca element in the calcium composite oxide particles ((Y element / Ca element) × 100) is 0.0001 to 10 mol% in terms of atoms. It said calcium complex oxide particles is further phosphor according to claim 1 or 2 any one of claims, characterized in that it contains an oxide of at least one element selected from Sr and Ba (M ¹ element) material.   The phosphor material according to any one of claims 1 to 3, which has a maximum emission peak at 250 to 270 nm.   Heat-treating and thermally decomposing a coated product in which the surface of calcium oxide precursor particles converted to calcium oxide particles by thermal decomposition is coated with yttrium oxide precursor converted to yttrium oxide by thermal decomposition A phosphor material obtained by performing a heat treatment step to obtain calcium composite oxide particles containing yttrium oxide.   6. The fluorescence according to claim 5, wherein the molar ratio of Y element to Ca element in the coated product ((Y element / Ca element) × 100) is 0.0001 to 10 mol% in terms of atoms. Body material. The coating is treated further according to claim 5 or 6 any one, characterized in that the precursor of an oxide of at least one element selected from Sr and Ba (M ¹ element) is also covered The phosphor material described. Wherein the molar ratio of ^{M 1} element to a total of ^{M 1} element and Ca element of the coating treated in ^{({M 1} element / ^{(M 1} element + Ca element)} × 100) is, in terms of atom, 0.01 to 10 mol% The phosphor material according to claim 7, wherein: By adding a Y element source to an aqueous slurry in which calcium oxide precursor particles converted into calcium oxide particles by thermal decomposition are dispersed in a dispersion medium, and then hydrolyzing the Y element source, the Y element A coating treatment step of depositing a source hydrolyzate on the surface of the calcium oxide precursor particles to obtain a coating treated product;
A heat treatment step of obtaining calcium composite oxide particles containing yttrium oxide by heat-treating and heat-decomposing the coated product;
A method for producing a phosphor material, comprising: Wherein in the coating step, the aqueous slurry further method for manufacturing a fluorescent material according to claim 9, wherein the addition of one or more elements (M ¹ element) source selected from Sr and Ba.   The method for producing a phosphor material according to any one of claims 9 to 10, wherein, in the heat treatment step, a heat treatment temperature is 500 to 1600 ° C.