JP2007113021A - Inorganic phosphor and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an inorganic phosphor which satisfies various characteristics required corresponding to respective usages when applying the inorganic phosphor to display apparatuses such as CRT, fluorescent lamps, and other various kinds of apparatuses or materials, and especially which has a small particle size, is high in luminance, and further, to provide a method of manufacturing a high luminance inorganic phosphor very superior in evenness which does not need classification and mechanical pulverizion after baking and is low in cost. <P>SOLUTION: The inorganic phosphor has a variation cefficient of 50% or less in content ratio of distribution among particles of the constituents constituting parent nuclei and activation parts of the inorganic phosphor. Also, the method of manufacturing the inorganic phosphor by forming a precursor of the inorganic phosphor by a sol-gel method, then baking the precursor of the inorganic phosphor, is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to an inorganic phosphor and a method for producing the same.

  Various phosphors have been used for a long time in display devices such as CRTs and fluorescent lamps, and many techniques for improving various characteristics of these phosphors have been disclosed. Among the various characteristics of the phosphor, the luminance characteristic is one of the most important characteristics, and a phosphor having high luminance is desired.

  In addition, conventional phosphors that emit light by electron beams and ultraviolet rays can be used for new applications if there is a phosphor that does not require such a special excitation source. It is necessary in the future from the viewpoint of energy saving. For example, an organic phosphor can be mentioned as a phosphor that shines in daylight. However, since the phosphor itself is colored, it is not possible to obtain pure emission, and storage stability is low.

  Further, in terms of the production method, it has been difficult to control the activator into each particle in the conventional method of mixing and melting a metal oxide. For this reason, an excessive amount of activator was required as a raw material, but if it can be used reliably, it will lead to cost reduction, and a particle design technique is required.

  In the conventional general phosphor manufacturing method (mixing raw material powder dry and firing together with a small amount of flux), it is difficult to control the individual phosphor particles microscopically, resulting in macroscopic brightness and other performance. Was not satisfactory enough.

  For the purpose of forming a dense, homogeneous and high-luminance phosphor screen, phosphor particles having a concentration distribution along the direction from the particle surface toward the center have been disclosed (for example, see Patent Document 1). So far, particles having a remarkably uniform composition and phosphor particles defining the distribution of the content of each composition have not been disclosed.

  On the other hand, as a method for producing an inorganic phosphor for the purpose of improving various properties such as luminance, a production method including a step of mixing and preparing a metal alkoxide in a solution state is disclosed (for example, see Patent Document 2). Detailed embodiments that are highly effective are not disclosed. Moreover, although the manufacturing method including the process of hydrolyzing the mixed solution containing a metal alkoxide and synthesizing a composite oxide sol aqueous solution is disclosed (for example, refer to Patent Document 3), the target product in this case is a fluorescent porous material. The particles are different from the object of the present invention.

As described above, many technologies have been disclosed that have been devised in the composition of various inorganic phosphors and the production methods of the phosphors for the purpose of improving various characteristics such as luminance, but those that are sufficiently satisfactory are disclosed. Not obtained.
Japanese Patent Laid-Open No. 9-328681 JP-A-6-287551 JP-A-11-61113

  Therefore, the present invention has a particularly small particle size while satisfying various characteristics required for each application in applying an inorganic phosphor to a display device such as a CRT, a fluorescent lamp, and various other devices and materials. An object of the present invention is to provide an inorganic phosphor having high brightness. It is another object of the present invention to provide a method for producing an inorganic phosphor which is unnecessary in classification and mechanical pulverization after firing and is low in cost and excellent in homogeneity and having high brightness.

  The above object of the present invention can be achieved by the following configuration.

  1. An inorganic phosphor characterized in that the variation coefficient of the interparticle distribution of the content ratio of the composition constituting the mother nucleus and the activation part of the inorganic phosphor particles is 50% or less.

  2. 2. The inorganic phosphor according to 1 above, wherein an average particle size of the inorganic phosphor is 1.0 μm or less.

  3. 3. The inorganic phosphor as described in 1 or 2 above, wherein the coefficient of variation in particle size distribution of the inorganic phosphor is 100% or less.

  4). The inorganic phosphor according to any one of 1 to 3 is produced by forming a precursor of an inorganic phosphor by a sol-gel method, and then firing the precursor of the inorganic phosphor. An inorganic phosphor manufacturing method.

  5. 5. The method for producing an inorganic phosphor as described in 4 above, wherein when the precursor of the inorganic phosphor is formed by the sol-gel method, at least one raw material addition rate is added at 3.0 ml / min or less.

  6). 6. The method for producing an inorganic phosphor as described in 4 or 5 above, wherein after the precursor of the inorganic phosphor is formed, the firing time of the precursor of the inorganic phosphor is 15 minutes / g or less.

  7). 7. The method for producing an inorganic phosphor according to any one of 4 to 6, wherein a step of pulverization and / or classification is not performed after the firing of the precursor of the inorganic phosphor.

  According to the present invention, when applying an inorganic phosphor to a display device such as a CRT, a fluorescent lamp, and various other devices and materials, while satisfying various properties required according to each application, particularly with a small particle size. It was possible to provide an inorganic phosphor having high brightness, and further to provide a method for producing an inorganic phosphor having high homogeneity and high brightness, which does not require classification and mechanical grinding after firing and is low in cost. .

  The present invention is described in more detail below. The excitation wavelength of the inorganic phosphor of the present invention is preferably 380 nm to 430 nm, more preferably 390 nm to 420 nm, still more preferably 400 nm to 410 nm. Originally, phosphors used emission lines of electron beams, mercury, argon, and xenon as excitation sources, and other excitation sources have not appeared for many years and have been used exclusively. However, if it can be excited with lower energy, it can be used in daylight, and a new application such as adding fluorescence to a drawing composed of subtractive color mixture will be born. For example, for an active light-emitting liquid crystal, if the color filter is made of the current phosphor, the backlight must be made into black light or shorter ultraviolet rays, and the lifetime of the liquid crystal molecules will be shortened. Can use an existing backlight, and the lifetime of liquid crystal molecules can be secured at a practical level. It can also be used for color conversion organic EL. Organic phosphors have problems such as short lifetime and narrow color gamut, but if the phosphor of the present invention is used, a color gamut equivalent to CRT can be secured and the lifetime is long. It can also be used as a decorative or drawing fluorescent color. At that time, if excitation is around 400 nm, coloring due to absorption is at a level that does not cause a problem for the human eye.

  The liquid phase method is suitable for producing the phosphor of the present invention. In the solid-phase method, each composition must be melted microscopically and waiting for diffusion mixing to occur, and in some cases, firing has to be repeated many times. This causes a considerable loss in time and energy. However, when a precursor in which elements are controlled and incorporated by a liquid phase method is used, a high-luminance phosphor can be obtained only by applying crystallization energy. Therefore, when compared under the same firing conditions, the liquid phase method is overwhelmingly advantageous in terms of energy. In some cases, even if macrocrystallization does not occur, light can be emitted if the assembly of elements is controlled. For example, even when the temperature does not react in the solid phase method, such as an aluminate-based phosphor, light can be emitted by using a precursor in the liquid phase method.

  As the liquid phase method referred to here, a general method such as a sol-gel method, a coprecipitation method, or a crystallization method can be used. Any solvent may be used as the solvent for the sol-gel method as long as the reaction raw material dissolves, but ethanol is desirable from the viewpoint of environment. The reaction initiator may be an acid or a base, but a base is more preferable from the viewpoint of hydrolysis rate. As the type of base, general substances such as NaOH and ammonia can be used if the reaction starts, but ammonia is preferable in view of ease of removal. The method of mixing the reaction initiator may be added to the ground first, may be added simultaneously with the raw material, or may be added to the raw material, but is added to the ground first to improve uniformity. Is preferred. When a plurality of reaction raw materials are used, the addition order of the raw materials may be different at the same time, an appropriate order can be assembled depending on the activity, and a double alkoxide may be formed in some cases.

Any solvent may be used as a solvent for the crystallization method and the coprecipitation method as long as the reaction raw material dissolves, but water is preferable because of easy control of the supersaturation degree. When a plurality of reaction raw materials are used, the order of addition of the raw materials may be simultaneous or different, and an appropriate order can be assembled depending on the activity.
In any method, the temperature, addition rate, stirring rate, pH, etc. may be controlled during the reaction, and ultrasonic waves may be irradiated during the reaction. A surfactant or polymer may be added to control the particle size. When the raw materials have been added, the liquid may be concentrated and / or aged. The obtained precipitate may be filtered, washed and dried, or may be fired simultaneously with drying. Further, the precipitate may be irradiated with ultrasonic waves, and if the light is emitted without firing, the firing step can be omitted.

  Firing can be performed in a reducing atmosphere or an oxidizing atmosphere, and can be selected as necessary. In addition, the phosphor of the present invention can be fired at a temperature lower by 100 degrees or more than the solid phase method to obtain the same luminance, which is very advantageous in terms of cost and productivity. Further, since the firing process proceeds sufficiently without mixing impurities such as flux, the rate of deactivation is reduced, which is advantageous from the viewpoint of luminous efficiency.

Further, in the liquid phase method, each element can be uniformly mixed at the solution stage, and can be controlled and incorporated by adjusting the reaction conditions, thereby reducing unreacted raw materials. Although how to incorporate the activator becomes a problem, it is desirable that 70% or more, preferably 80% or more, more preferably 90% or more of the added activator raw material contribute to the reaction. As a result, the amount of activator added can be reduced. The activator content of the phosphor of the present invention is preferably 0.03 mol% or less of the crystal matrix, more preferably 0.025 mol%, and still more preferably 0.02 mol% or less. For example, when Eu is activated in Ba ₂ SiO ₄ , 0.01 mol% is sufficient in the liquid phase method where 0.035 mol% was necessary in the conventional method. This is due to effects such as reliable Eu incorporation and delocalization. Further, in this case, the element abundance ratio (%) Eu / (Ba + Si + O + Eu) × 100 is 0.5% in the conventional method and 0.14% in the liquid phase method, which requires about 1/3 amount. This is particularly important in terms of cost.

  In the inorganic phosphor particles of the present invention, the coefficient of variation in the interparticle distribution of the composition constituting the mother nucleus and the activation part is 50% or less, more preferably 30% or less, and 15% or less. Most preferably it is.

  As a method for measuring the content ratio of the composition contained in the particles, the composition of each particle can be measured using a secondary ion mass spectrometry (SIMS) apparatus having a high resolution of submicron to nanometer order. it can. It is preferable to measure by placing phosphor particles on a sample stage and depositing carbon or the like. In particular, when measuring phosphor particles having a particle diameter of 1 μm or less, it is also possible to measure by crushing the particles to a certain thickness. Furthermore, as a method for calculating the interparticle distribution variation coefficient of the content, the standard deviation of the composition content when measuring the composition content of at least 100 phosphor particles with a secondary ion mass spectrometry (SIMS) apparatus is averaged. It is a value obtained by multiplying the value divided by the content rate by 100.

  In the inorganic phosphor particles of the present invention, the number of particles having a uniform distribution of the composition constituting the mother nucleus and the activation part is preferably 50% or more, more preferably 60% or more. 80% or more is most preferable.

  Here, the distribution of the composition being uniform within the particle means that the content of a certain composition is microscopically constant in any region in one particle. More specifically, in the microscopic distribution measurement method to be described later, the difference in the content rate in each section of a certain composition is 20% or less of the theoretical value of the content rate of the composition.

  As a method for measuring the microscopic distribution of the composition contained in the particles, a transmission electron microscope (TEM) is used to analyze characteristic X-rays generated from the sample when irradiated with an electron beam, one by one. The internal composition distribution of the particles can be measured. It is possible to continuously cut out the phosphor particles as the sample as, for example, a section having a thickness of about 50 nm, place the section on a mesh for electron microscope observation, perform carbon deposition, and observe by the transmission method. Further, as a method for calculating the ratio of particles having a microscopically uniform composition distribution, at least 100 phosphor particles may be measured by a transmission electron micrograph and the ratio calculated.

  In the inorganic phosphor particles of the present invention, the number of phosphor particles that do not emit light when irradiated with light having an excitation wavelength is preferably 20% or less, more preferably 15% or less, and further preferably 10% or less. Most preferably it is.

  As a method for measuring the luminance of light emitted when irradiated with light having an excitation wavelength, each particle is measured using a scanning near-field atomic force microscope (SNOAM: Scanning Near-field Optical / Atomic-Force Microscopy). Can be measured. It is possible to measure by setting the wavelength of the excitation light irradiated through the optical fiber and the wavelength of the emission color to be detected by placing the phosphor particles on the sample stage. Further, as a method for calculating the ratio of particles that do not emit light even when irradiated with light of an excitation wavelength, it is only necessary to measure at least 100 phosphor particles with a scanning near-field atomic force microscope and calculate the ratio.

  The phosphor of the present invention desirably has a uniform luminescent color. Specifically, the number of particles of phosphor particles included in a circle having a radius of 0.055 centered on an arbitrary point in the XY color coordinate system. 70% or more, preferably 80% or more, and more preferably 90% or more.

Any composition of the phosphor may be used as long as the present invention is satisfied, and examples thereof include rare earth element activated metal oxides, metal sulfides or metal sulfates, and halophosphate compounds. Examples are given below, but the present invention is not limited thereto.
Red:
Y ₂ O ₂ S: Eu ³⁺
Gd ₂ O ₂ S: Eu ³⁺
YVO ₄ : Eu ³⁺
Y ₂ O ₂ S: Eu, Sm
SrTiO ₃ : Pr
BaSi ₂ Al ₂ O ₈ : Eu ²⁺
BaMg ₂ Al ₁₆ O ₂₇ : Eu ²⁺
Y _0.65 Gd _0.35 BO ₃ : Eu ³⁺
La ₂ O ₂ S: Eu ³⁺ , Sm
Green:
Ba ₂ SiO ₄ : Eu ²⁺
Zn (Ga, Al) ₂ O ₄ : Mn
Y ₃ (Al, Ga) ₅ O ₁₂ : Tb
Y ₂ SiO ₅ : Tb
ZnS: Cu,
Zn ₂ SiO ₄ : Mn
Blue:
BaAl ₂ Si ₂ O ₈ : Eu ²⁺
BaMgAl ₁₄ O ₂₃ : Eu ²⁺
Y ₂ SiO ₅ : Ce
ZnGa ₂ O ₄
ZnS: Ag, Cl
In the present invention, for example, by controlling the composition of individual particles uniformly between particles and within the particles to a level that has not been known in the past, it was possible to obtain high-luminance emission with a smaller amount of phosphor. . As a result, it is possible to further reduce the cost in obtaining the current performance.

  The inorganic phosphor of the present invention is preferably produced by a liquid phase method. Furthermore, depending on the composition of the inorganic phosphor particles, the sol-gel method is the most preferable among the liquid phase methods. The manufacturing method by the sol-gel method will be described later.

  When an inorganic phosphor is manufactured by a liquid phase method, it is a reaction in a solution system rather than a dry type as in the past, and thus an inorganic phosphor that is remarkably excellent in control of individual particles and uniformity among particles is manufactured. be able to.

Reference example 1
Y ₂ SiO ₅ : Ce, Tb produced by the solid phase method is A, Ba ₂ SiO ₄ : Eu produced by the solid phase method is B1, and one produced by the liquid phase method is B2.

  In the synthesis method of A and B1, stoichiometric amounts of the respective metal oxides were mixed and baked at 1000 ° C. for 2 hours. B2 was prepared by dissolving 8.3 g of tetraethoxysilane and 0.097 g of europium acetylacetonate in 150 ml of ethanol, and adding dropwise to a solution of water: ethanol = 150 ml: 150 ml adjusted to pH 10 with ammonia. The solution was concentrated to 295 ml of a 0.3M barium nitrate aqueous solution, aged at 60 ° C. for 10 hours, filtered, washed, dried, and calcined at 1000 ° C. for 2 hours.

  The results of measuring the emission intensity of A and B are shown below. This is expressed as a relative intensity with A as a reference and 254 nm excitation as a reference. The measurement is based on PTI-2000 manufactured by Otsuka Electronics.

  Thus, a phosphor suitable for near-ultraviolet excitation could be obtained. In addition, the liquid phase method has a brightness of about 1.2 times or more under the same firing conditions as compared with the solid phase method.

Reference example 2
Ba ₂ SiO ₄ : Eu was synthesized by changing the amount of Eu as shown in Table 2. Otherwise, B21 to B14 and B21 to 24 were prepared in the same manner as B1 and B2. Table 2 shows the relative intensities with the emission intensity when adding 0.05 mol% of Eu by the solid phase method as 100. The excitation wavelength is 410 nm and the emission wavelength is 501 nm. Further, the measurement of the number of particles entering a circle with a radius of 5 in the XY color coordinate system is a result of irradiating 25 spots on 0.2 g of phosphor with the slit of the excitation light of the fluorometer shifted.

  As described above, it was found that the same luminance was obtained and the uniformity of the luminescent color was high with about 1/7 of the activator of the solid phase method.

  During the synthesis of B21, the gel filtrate was collected and the amount of remaining Eu was measured by ICP. Therefore, it can be seen that all of the added Eu was incorporated in the particles. Further, in the case of the solid phase method, the luminance of the activator becomes the same at 7 times the amount of the sol-gel method. Therefore, the effective Eu utilization rate in the solid phase method is 13% based on the liquid phase method B21. In addition, in the liquid phase method, there is no change in luminance such as B22, 23, 24, and it can be seen that the liquid phase method is already saturated at 0.02. On the contrary, the addition of more promotes the localization of Eu, there is a possibility that the luminance is lowered, and it is useless from the viewpoint of cost.

Example 1
<Preparation of Sample 3-1>
Barium, silica, and europium oxide raw material powders were mixed at a molar ratio of barium: silica: europium = 2: 1: 0.005 and fired at 1000 ° C. for 2 hours to obtain a sample 3-1. Got. As a result of measuring the average particle size and the particle size distribution with a scanning electron microscope, the average particle size was 3.92 μm and the particle size distribution was 344%.

<Preparation of Sample 3-2>
A solution prepared by dissolving 8.3 g of tetraethoxysilane and 0.097 g of europium acetylacetonate in 150 ml of ethanol, 295 ml of a 0.3M barium nitrate aqueous solution, and 300 ml of a mixture of water: ethanol = 1: 1 were adjusted to pH 10 with ammonia. The solution was added dropwise to the mother liquor at 5.0 ml / min. After completion of the dropwise addition, 0.75 g of polyoxyethylene sorbitan trioleate was added and concentrated to dryness with a rotary evaporator. The remaining solid was dispersed and washed in ethanol, filtered, washed again with isopropanol, dried, and calcined at 400 ° C. for 5 hours and then at 900 ° C. for 2 hours to obtain Sample 3-2. The average particle size was 0.88 μm and the particle size distribution was 61%.

<Preparation of Sample 3-3>
In the preparation method of Sample 3-2 above, Sample 3 was prepared in the same manner as Sample 3-2 except that the dropping rate of the ethanol solution of tetraethoxysilane and europium acetylacetonate was changed to 3.0 ml / min. -3 was obtained. The average particle size was 0.92 μm, and the particle size distribution was 68%.

<Preparation of Sample 3-4>
In the preparation method of Sample 3-2 above, Sample 3 was prepared in the same manner as Sample 3-2 except that the dropping rate of the ethanol solution of tetraethoxysilane and europium acetylacetonate was changed to 2.0 ml / min. -4 was obtained. The average particle size was 0.94 μm and the particle size distribution was 71%.

<Preparation of Sample 3-5>
In the preparation method of Sample 3-2 above, Sample 3 was prepared in the same manner as Sample 3-2 except that the dropping rate of the tetraethoxysilane and europium acetylacetonate ethanol solution was changed to 1.0 ml / min. -5 was obtained. The average particle size was 0.97 μm and the particle size distribution was 72%.

<Measurement of composition content>
For each of Sample 3-1 to Sample 3-5, the content of silica was measured for 100 particles using a secondary ion mass spectrometry (SIMS) apparatus, and the distribution between the particles was calculated. Moreover, as a result of performing the same measurement also about barium and europium, the substantially same value was obtained. These results are shown in Table 3.

<Measurement of brightness>
For each of Sample 3-1 to Sample 3-5, luminance was measured in the same manner as in Reference Example 1. Table 3 shows the relative luminance of Sample 3-2 to Sample 3-5 when the luminance of Sample 3-1 is 100.

  From Table 3, it was confirmed that the phosphor particles of the present invention having a narrow interparticle distribution of each composition content had higher luminance than the comparative particles.

Reference example 3
<Preparation of Sample 4-1>
Barium, silica, and europium oxide raw material powders were mixed at a molar ratio of barium: silica: europium = 2: 1: 0.005 and fired at 1000 ° C. for 2 hours to obtain Sample 4-1. Got. As a result of measuring the average particle size and the particle size distribution with a scanning electron microscope, the average particle size was 3.92 μm and the particle size distribution was 344%.

<Preparation of sample 4-2>
A solution prepared by dissolving 8.3 g of tetraethoxysilane and 0.097 g of europium acetylacetonate in 100 ml of ethanol, 295 ml of a 0.3M barium nitrate aqueous solution, and 300 ml of a mixture of water: ethanol = 1: 1 were adjusted to pH 10 with ammonia. It was simultaneously added dropwise to the mother liquor. After completion of the dropwise addition, 0.75 g of polyoxyethylene sorbitan trioleate was added and concentrated to dryness with a rotary evaporator. The remaining solid was dispersed and washed in ethanol, filtered, washed again with isopropanol, dried, and calcined at 400 ° C. for 5 hours and then at 900 ° C. for 2 hours to obtain Sample 4-2. The average particle size was 0.85 μm and the particle size distribution was 62%.

<Preparation of Sample 4-3>
In the preparation method of the above sample 4-2, a sample 4-3 was obtained in the same manner as the preparation method of the sample 4-2 except that the amount of ethanol for dissolving tetraethoxysilane and europium acetylacetonate was changed to 180 ml. It was. The average particle size was 0.91 μm and the particle size distribution was 65%.

<Preparation of Sample 4-4>
Sample 4-4 was prepared in the same manner as Sample 4-2 except that the amount of ethanol used to dissolve tetraethoxysilane and europium acetylacetonate was changed to 250 ml. It was. The average particle size was 0.96 μm, and the particle size distribution was 73%.

<Preparation of Sample 4-5>
Sample 4-5 was prepared in the same manner as Sample 4-2 except that the amount of ethanol used to dissolve tetraethoxysilane and europium acetylacetonate was changed to 300 ml. It was. The average particle size was 0.98 μm and the particle size distribution was 77%.

<Measurement of internal composition distribution>
For each of Sample 4-1 to Sample 4-5, the distribution of the internal composition of 100 particles was measured using a transmission electron microscope (TEM), and the ratio of microscopically uniform particles was calculated. These results are shown in Table 4.

<Measurement of brightness>
In the same manner as in Example 1, the luminance of each of the samples 4-1 to 4-5 was measured. Table 4 shows the relative luminance of Sample 4-2 and Sample 4-5 when the luminance of Sample 4-1 is 100.

  From Table 4, it was confirmed that the phosphor particles having a fine particle ratio with a uniform internal composition distribution have higher luminance than the phosphor particles having a small uniform particle ratio.

Example 2
<Measurement of internal composition distribution>
For Sample 3-1 to Sample 3-5 prepared in Example 1, the luminance was measured for 100 particles using a scanning near-field atomic force microscope (SNOAM), and the ratio of particles that did not emit light was calculated. . These results are shown in Table 5.

<Measurement of brightness>
Similarly to Example 1, the luminance was measured for each of Sample 3-1 to Sample 3-5. Table 5 shows the relative luminance of Sample 3-2 to Sample 3-5 when the luminance of Sample 3-1 is 100.

  From Table 5, it was confirmed that the phosphor particles having a small particle ratio that does not emit light even when irradiated with excitation light have higher luminance than the comparative particles.

Reference example 4
Synthesis of Phosphor 6-1 Ba ₂ SiO ₄ : Eu ²⁺ The phosphor was prepared as primary particles by the liquid phase synthesis flow shown below. Solution A in which tetraethoxysilane and europium (trivalent) acetylacetonate complex are dissolved in ethanol is solution A, and solution in which triethoxyaluminum is dissolved in ethanol is solution B. The solutions A and B were added dropwise to water-ethanol to which ammonia was added with stirring at a rate of about 1 ml / min to prepare a sol. The obtained sol was concentrated about 15 times with an evaporator, and 500 ml of 0.033 mol / l barium nitrate aqueous solution was added thereto to cause gelation.

  The obtained wet gel was aged at 40 ° C. for 10 minutes in a closed container. Thereafter, the mixture was added to ethanol (about 300 ml) with stirring at 1 ml / min, separated by filtration using filter paper (Advantec 5A), and dried at room temperature.

The dried gel was subjected to heat treatment at 1000 ° C. for 2 hours in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 6-1.

Synthesis of Phosphor 6-2 Ba ₂ SiO ₄ : Eu ²⁺ The phosphor was produced as primary particles by the liquid phase synthesis flow shown below. Solution A in which tetraethoxysilane and europium (trivalent) acetylacetonate complex are dissolved in ethanol is solution A, and solution in which triethoxyaluminum is dissolved in ethanol is solution B. The solutions A and B were added dropwise to water-ethanol to which ammonia was added with stirring at a rate of about 1 ml / min to prepare a sol. The obtained sol was concentrated about 15 times with an evaporator, and 500 ml of 0.033 mol / l barium nitrate aqueous solution was added thereto to cause gelation.

  The obtained wet gel was aged at 60 ° C. for 10 hours in a closed container. Thereafter, the mixture was added to ethanol (about 300 ml) with stirring at 1 ml / min, separated by filtration using filter paper (Advantec 5A), and dried at room temperature.

The dried gel was heat-treated at 1000 ° C. for 2 hours in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 6-2.

Synthesis of Phosphor 6-3 Ba ₂ SiO ₄ : Eu ²⁺ The phosphor was produced as primary particles by the liquid phase synthesis flow shown below. Solution A in which tetraethoxysilane and europium (trivalent) acetylacetonate complex are dissolved in ethanol is solution A, and solution in which triethoxyaluminum is dissolved in ethanol is solution B. The solutions A and B were added dropwise to water-ethanol to which ammonia was added with stirring at a rate of about 1 ml / min to prepare a sol. The obtained sol was concentrated about 15 times with an evaporator, and 500 ml of 0.033 mol / l barium nitrate aqueous solution was added thereto to cause gelation.

  The obtained wet gel was aged at 60 ° C. for 10 hours with stirring in a closed container. Thereafter, the mixture was added to ethanol (about 300 ml) with stirring at 1 ml / min, separated by filtration using filter paper (Advantec 5A), and dried at room temperature.

The dried gel was heat-treated at 1000 ° C. for 2 hours in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 6-3.

  Next, to 10 g of the obtained phosphor 6-1, 30 g of butyral (BX-1) dissolved in a mixed solution of toluene / ethanol = 1/1 (300 g) was added and stirred, and then the wet film thickness was 200 μm. It was applied on glass. The obtained coated glass was heat-dried in an oven at 100 ° C. for 4 hours to produce a phosphor film 6-1.

  In addition, a phosphor film 6-2 coated with phosphor 6-2 and a phosphor film 6-3 coated with phosphor 6-3 were produced by the same method.

  These fluorescent films were irradiated with ultraviolet rays having a wavelength of 147 nm and near-ultraviolet rays having a wavelength of 405 nm, and the fluorescence intensity was measured. The values were expressed as relative intensities where the value of the fluorescent film 6-1 was 100, respectively.

Reference Example 5
Synthesis of Phosphor 7-1 Ba ₂ SiO ₄ : Eu ²⁺ The phosphor was produced as primary particles by the liquid phase synthesis flow shown below. Solution A in which tetraethoxysilane and europium (trivalent) acetylacetonate complex are dissolved in ethanol is solution A, and solution in which triethoxyaluminum is dissolved in ethanol is solution B. The solutions A and B were added dropwise to water-ethanol to which ammonia was added with stirring at a rate of about 1 ml / min to prepare a sol. The obtained sol was concentrated about 15 times with an evaporator, and 500 ml of 0.033 mol / l barium nitrate aqueous solution was added thereto to cause gelation.

  The obtained wet gel was aged at 60 ° C. for 10 hours in a closed container. Thereafter, the mixture was added to ethanol (about 300 ml) with stirring at 1 ml / min, separated by filtration using filter paper (Advantec 5A), and dried at room temperature.

The dried gel was subjected to heat treatment at 1000 ° C. for 2 hours in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 7-1.

Synthesis of Phosphor 7-2 Ba ₂ SiO ₄ : Eu ²⁺ The phosphor was produced as primary particles by the liquid phase synthesis flow shown below. Solution A in which tetraethoxysilane and europium (trivalent) acetylacetonate complex are dissolved in ethanol is solution A, and solution in which triethoxyaluminum is dissolved in ethanol is solution B. The solutions A and B were added dropwise to water-ethanol to which ammonia was added with stirring at a rate of about 1 ml / min to prepare a sol. The obtained sol was concentrated about 15 times with an evaporator, and 500 ml of 0.033 mol / l barium nitrate aqueous solution was added thereto to cause gelation.

  The obtained wet gel was irradiated with ultrasonic waves of 20 KHz for 1 hour and further allowed to stand at 60 ° C. for 10 hours in a sealed container. The solution was collected by filtration using filter paper (Advantec 5A) and dried at room temperature.

The dried gel was heat-treated at 1000 ° C. for 2 hours in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 7-2.

Synthesis of Phosphor 7-3 Ba ₂ SiO ₄ : Eu ²⁺ The phosphor was produced as primary particles by the liquid phase synthesis flow shown below. Solution A in which tetraethoxysilane and europium (trivalent) acetylacetonate complex are dissolved in ethanol is solution A, and solution in which triethoxyaluminum is dissolved in ethanol is solution B. The solutions A and B were added dropwise to water-ethanol to which ammonia was added with stirring at a rate of about 1 ml / min to prepare a sol. The obtained sol was concentrated about 15 times with an evaporator, and 500 ml of 0.033 mol / l barium nitrate aqueous solution was added thereto to cause gelation.

  The obtained wet gel was aged at 60 ° C. for 10 hours in a closed container. Thereafter, the mixture was added to ethanol (about 300 ml) with stirring at 1 ml / min, separated by filtration using filter paper (Advantec 5A), and dried at room temperature.

The dried gel was subjected to heat treatment at 1000 ° C. for 15 minutes in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 7-3.

Synthesis of Phosphor 7-4 Ba ₂ SiO ₄ : Eu ²⁺ The phosphor was produced as primary particles by the liquid phase synthesis flow shown below. Solution A in which tetraethoxysilane and europium (trivalent) acetylacetonate complex are dissolved in ethanol is solution A, and solution in which triethoxyaluminum is dissolved in ethanol is solution B. The solutions A and B were added dropwise to water-ethanol to which ammonia was added with stirring at a rate of about 1 ml / min to prepare a sol. The obtained sol was concentrated about 15 times with an evaporator, and 500 ml of 0.033 mol / l barium nitrate aqueous solution was added thereto to cause gelation.

  The obtained wet gel was irradiated with ultrasonic waves of 20 KHz for 1 hour and further allowed to stand at 60 ° C. for 10 hours in a sealed container. The solution was collected by filtration using filter paper (Advantec 5A) and dried at room temperature.

The dried gel was heat-treated at 1000 ° C. for 15 minutes in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 7-4.

  Next, 30 g of butyral (BX-1) dissolved in a mixed solution of toluene / ethanol = 1/1 (300 g) was added to 10 g of the obtained phosphor 7-1 and stirred, and then the wet film thickness was 200 μm. It was applied on glass. The obtained coated glass was heat-dried in an oven at 100 ° C. for 4 hours to produce a fluorescent film 7-1.

  Further, in the same manner, the phosphor film 7-2 coated with the phosphor 7-2, the phosphor film 7-3 coated with the phosphor 7-3, and the phosphor film 7- coated with the phosphor 7-4. 4 was produced.

  These fluorescent films were irradiated with ultraviolet rays having a wavelength of 147 nm and near-ultraviolet rays having a wavelength of 405 nm, and the fluorescence intensity was measured. The values were expressed as relative intensities where the value of the fluorescent film 7-1 was 100, respectively.

  According to Table 7, phosphor films 7-2 and 7-4 using phosphors having an average particle diameter smaller than 1.0 μm are phosphor films 7-1 and 7− using phosphors having an average particle diameter larger than 1.0 μm. 3 shows that both the ultraviolet light (147 nm) and near ultraviolet light (405 nm) light sources have high emission intensity. In addition, a phosphor having a smaller particle diameter was obtained by reducing the heating time during firing.

Reference Example 6
Phosphor 8-1 (solid phase method) Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ Synthesis composition formula: Inorganic phosphor represented by Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ In doing so, it was produced by the following method.

1) Weighing Each raw material is weighed as accurately as possible SrCl ₂ 15.86 g (1.00 × 10 ⁻¹ mol)
H ₂ (PO ₄ ) 5.82 g (6.00 × 10 ⁻² mol)
Eu ₂ O ₃ 1.759 g (5.00 × 10 ⁻³ mol)
2) Mixing Each raw material is put into a plastic ball mill container, a TiO ₂ ball having a diameter of 3 mm and about 50 ml of ethanol are added to the lid, and the mixture is rotated overnight on a rotating table.

3) Removal of solvent The solvent is removed by vacuum filtration using Advantec 5C filter paper.

4) The naturally dried mixed raw material is placed in a crucible and fired in a 2% H ₂ —N ₂ atmosphere.
Thereby, phosphor 8-1 (solid phase method) was obtained.

Phosphor 8-2 (Sol-Gel Method) Synthesis of Sr ₁₀ (PO ₄ ) ₆ Cl ₂ : Eu ²⁺ The phosphor produced primary particles by the liquid phase method flow shown below. Strontium carbonate, sodium hydrogen phosphate, and europium chloride were each dissolved in pure water, and this was added dropwise to water added with ammonia at a rate of about 1 ml / min with stirring to obtain a precipitate. The resulting precipitate was collected by filtration and dried at room temperature.

The dried gel was subjected to heat treatment at 1000 ° C. for 2 hours in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 8-2 (sol-gel method).

  Next, 30 g of butyral (BX-1) dissolved in a mixed solution of toluene / ethanol = 1/1 (300 g) was added to 10 g of the obtained phosphor 8-1, and the mixture was stirred. It was applied on glass. The obtained coated glass was heat-dried in an oven at 100 ° C. for 4 hours to produce a phosphor film 8-1.

  In addition, a phosphor film 8-2 coated with phosphor 8-2 was produced by the same method.

  These fluorescent films were irradiated with ultraviolet rays having a wavelength of 147 nm and near-ultraviolet rays having a wavelength of 405 nm, and the fluorescence intensity was measured. The values were expressed as relative intensities where the value of the fluorescent film 8-1 was 100, respectively.

From Table 8, the fluorescent film using the phosphor prepared by the sol-gel method emits light in both ultraviolet light (147 nm) and near ultraviolet light (405 nm) as compared with the fluorescent film using the phosphor prepared by the solid phase method. It is understood that is high Reference Example 7
Phosphor 9-1 (solid phase method) BaAl ₂ Si ₂ O _8: Synthesis composition formula ^{_{Eu 2+: BaAl 2 Si 2 O}} 8: In producing the inorganic phosphor represented by Eu ^2+, the following method Manufactured with.

1) Weighing Each raw material is weighed as accurately as possible 3.256 g (1.65 × 10 ⁻² mol) BaCO ₃
SiO ₂ 1.980 g (3.30 × 10 ⁻² mol)
Eu ₂ O ₃ 0.047 g (1.15 × 10 ⁻² mol)
Al ₂ O ₃ 3.36 g (3.30 × 10 ⁻² mol)
2) Mixing Each raw material is put into a plastic ball mill container, a TiO ₂ ball having a diameter of 3 mm and about 50 ml of ethanol are added to the lid, and the mixture is rotated overnight on a rotating table.

3) Removal of solvent The solvent is removed by vacuum filtration using Advantec 5C filter paper.

4) The naturally dried mixed raw material is placed in a crucible and fired in a 2% H ₂ —N ₂ atmosphere.
Thereby, phosphor 9-1 (solid phase method) was obtained.

Phosphor 9-2 (sol-gel method) Synthesis of BaAl ₂ Si ₂ O ₈ : Eu ²⁺ Primary particles were prepared by the liquid phase method synthesis flow shown below for the phosphor. Tetraethoxysilane and europium (trivalent) acetylacetonate complex were dissolved in ethanol and added dropwise to water-ethanol to which ammonia was added at a rate of about 1 ml / min with stirring to prepare a sol. The obtained sol was concentrated about 15 times with an evaporator, and 295 ml of a 0.3 mol / l barium nitrate aqueous solution was added thereto for gelation.

  The obtained wet gel was aged overnight at 60 ° C. in a closed container. Thereafter, the mixture was added to ethanol (about 300 ml) with stirring at 1 ml / min, separated by filtration using filter paper (Advantec 5A), and dried at room temperature.

The dried gel was heat-treated at 1000 ° C. for 2 hours in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 9-2 (sol-gel method).

  Next, 30 g of butyral (BX-1) dissolved in a mixed solution of toluene / ethanol = 1/1 (300 g) was added to 10 g of the obtained phosphor 9-1 and stirred. It was applied on glass. The obtained coated glass was heat-dried in an oven at 100 ° C. for 4 hours to produce a phosphor film 9-1.

In addition, a phosphor film 9-2 coated with phosphor 9-2 was produced by the same method.
These fluorescent films were irradiated with ultraviolet rays having a wavelength of 147 nm and near ultraviolet rays having a wavelength of 405 nm, and the fluorescence intensity was measured.

  According to Table 9, the phosphor film using the phosphor prepared by the sol-gel method emits light in both ultraviolet light (147 nm) and near ultraviolet light (405 nm) light sources than the phosphor film using the phosphor prepared by the solid phase method. Is high.

Reference Example 8
Phosphor 10-1 (solid phase method) Ba ₂ SiO _4: Synthesis composition formula Eu ^2+: Ba ₂ SiO _4: In producing the inorganic phosphor represented by Eu ^2+, was prepared by the following method.

1) Weighing Weigh each raw material as accurately as possible.

BaCO ₃ 15.783 g (4.0 mol)
2.403 g (2.0 mol) of SiO ₂
Eu ₂ O ₃ 0.704 g (0.1 mol)
2) Mixing Each raw material is put into a plastic ball mill container, a TiO ₂ ball having a diameter of 3 mm and about 50 ml of ethanol are added to the lid, and the mixture is rotated overnight on a rotating table.

3) Removal of solvent The solvent is removed by vacuum filtration using Advantec 5C filter paper.

4) The naturally dried mixed raw material is placed in a crucible and fired in a 2% H ₂ —N ₂ atmosphere.
Thereby, the phosphor 10-1 (solid phase method) was obtained.

Phosphor 10-2 (Sol-Gel Method) Synthesis of Ba ₂ SiO ₄ : Eu ²⁺ The phosphor was prepared as primary particles by the liquid phase synthesis flow shown below. Solution A in which tetraethoxysilane and europium (trivalent) acetylacetonate complex are dissolved in ethanol is solution A, and solution in which triethoxyaluminum is dissolved in ethanol is solution B. The solutions A and B were added dropwise to water-ethanol to which ammonia was added with stirring at a rate of about 1 ml / min to prepare a sol. The obtained sol was concentrated about 15 times with an evaporator, and 500 ml of 0.033 mol / l barium nitrate aqueous solution was added thereto to cause gelation.

  The obtained wet gel was aged overnight at 60 ° C. in a closed container. Thereafter, the mixture was added to ethanol (about 300 ml) with stirring at 1 ml / min, separated by filtration using filter paper (Advantec 5A), and dried at room temperature.

The dried gel was subjected to heat treatment at 1000 ° C. for 2 hours in a 2% H ₂ —N ₂ atmosphere to obtain phosphor 10-2 (sol-gel method).

  Next, to 10 g of the obtained phosphor 10-1, 30 g of butyral (BX-1) dissolved in a mixed solution of toluene / ethanol = 1/1 (300 g) was added and stirred, and then the wet film thickness was 200 μm. It was applied on glass. The obtained coated glass was heat-dried in an oven at 100 ° C. for 4 hours to produce a phosphor film 10-1.

  Moreover, the fluorescent film 10-2 which coated the fluorescent substance 10-2 by the same method was produced. These fluorescent films were irradiated with ultraviolet rays having a wavelength of 147 nm and near-ultraviolet rays having a wavelength of 405 nm, and the fluorescence intensity was measured. The values were expressed as relative intensities where the value of the fluorescent film 10-1 was 100, respectively.

  From Table 10, the phosphor film using the phosphor prepared by the sol-gel method emits light in both ultraviolet light (147 nm) and near ultraviolet light (405 nm) light sources than the phosphor film using the phosphor prepared by the solid phase method. Is high

Claims (7)

An inorganic phosphor characterized in that the variation coefficient of the interparticle distribution of the content ratio of the composition constituting the mother nucleus and the activation part of the inorganic phosphor particles is 50% or less. The inorganic phosphor according to claim 1, wherein the inorganic phosphor has an average particle size of 1.0 μm or less. The inorganic phosphor according to claim 1 or 2, wherein a coefficient of variation of a particle size distribution of the inorganic phosphor is 100% or less. The inorganic phosphor according to claim 1 is produced by forming a precursor of an inorganic phosphor by a sol-gel method, and then firing the precursor of the inorganic phosphor. An inorganic phosphor manufacturing method. 5. The method for producing an inorganic phosphor according to claim 4, wherein when forming the precursor of the inorganic phosphor by the sol-gel method, at least one raw material addition rate is added at 3.0 ml / min or less. 6. The method for producing an inorganic phosphor according to claim 4, wherein after the precursor of the inorganic phosphor is formed, the firing time of the precursor of the inorganic phosphor is 15 minutes / g or less. The inorganic phosphor manufacturing method according to any one of claims 4 to 6, wherein the inorganic phosphor precursor is not pulverized and / or classified after firing.