JP2001316663A - Fluorescent substance, process for its manufacture and fluorescent layer using the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fluorescent substance satisfying required performances such as brightness and a process for manufacturing the same. SOLUTION: A fluorescent particle emits a visible light when excited with an ultraviolet light having a wavelength of <=200 nm. A fluorescent layer contains a material which absorbs light having a wavelength within a range different from that of the visible light and is prepared by forming the fluorescent body in a liquid. The minor to major axis ratio of the fluorescent particle formed in a liquid phase is within the range of from 0.5 to 1. The fluorescent particle formed in a liquid phase, i.e. (Y, Gd)BO3: Eu is obtained by adding a boric acid solution to a solution of triisopropoxide yttrium, triisopropoxide gallium and europium acetyl acetate and calcining the generated precipitate. The fluorescent layer is obtained by applying onto a glass a paste prepared by mixing a Fe2O3 fine particle having a central particle size of from 10 to 30 nm with the fluorescent particle formed in a liquid phase.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a phosphor layer, a phosphor and a method for producing a phosphor.

[0002]

2. Description of the Related Art While phosphors are used as materials for converting electron beams or ultraviolet rays into visible light, various attempts have been made to improve brightness, contrast, luminous efficiency, color purity, durability and the like. For example, JP-A-11-131059 introduces a phosphor layer containing a material that absorbs light other than the emission wavelength of the phosphor, and improves color purity and contrast. Japanese Patent Application Laid-Open No. 11-199867 defines the distribution of the major axis length of particles, and improves the uniformity of the phosphor group. Japanese Patent Application Laid-Open No. H11-256149 discloses a phosphor with high luminance and little deterioration by applying the same oxide phosphor as the main component to the sulfide phosphor. Further, recently, as disclosed in Japanese Patent Application Laid-Open No. H11-236560, a composition suitable for being excited by short-wave ultraviolet rays for PDP has been disclosed.

[0003] Conventionally, a phosphor has been synthesized with a desired composition by mixing a solid raw material and utilizing thermal diffusion. Therefore, it is difficult to control the particle size, particle shape, composition, distribution, etc.,
In addition to an increase in manufacturing cost, an increase in waste, and an obstacle to processing, the effects of the various measures described above cannot be sufficiently obtained.

Also, luminous lamps, in particular compact luminous lamps and three-band luminous lamps (Dreibanden)
It is particularly advantageous to use as narrow green band-emitting compounds based on the typical terbium-emission with a maximum wavelength of approximately 541 to 543 nm as green component of the leuchtstamplampen.

Such compounds include the most important representatives of the luminescent cerium-magnesium-aluminates:
Austrian Patent 351,635 describes Tb (C
AT), lanthanum phosphate: German Patent No. 3,326,9
Ce and Tb (LAP) and lanthanum phosphate-silicate in U.S. Pat. No. 4,891,550 and U.S. Pat. No. 4,891,550: Ce, in DE 3,248,809.
Tb (LAPS) and Y ₂ SiO ₅ : European Patent No. 3
7,688, there is Ce, Tb. All these luminescent materials have high temperature stability and light yield (Leichta)
use). The disadvantage of these compounds is that the production costs are high due to the need for production temperatures of 1300-1600 ° C.

Another luminescent material having an emission maximum at 542 nm is gadolinium-magnesium-pentaborate: Ce, Tb described in EP 23,068. The characteristics of the luminescent CBT are 1
A relatively low production temperature slightly above 000 ° C. Due to their high stability and good luminous properties, they can be used in luminescent materials such as CAT, LAP, LAPS and Y ₂ Si.
O ₅ : Equivalent to Ce, Tb, but has the disadvantages of most borate phosphors that are relatively coarse with uneven particle size and difficult to process.

Japanese Unexamined Patent Publication (Kokai) No. 11-92133 discloses a phosphor having a composition capable of solving these problems, but unfortunately is not sufficient in luminance because it is manufactured by a solid phase method.

The red phosphor used for the fluorescent lamp is disclosed, for example, in the 1989 National Meeting of the Illuminating Engineering Institute, 337 pages of proceedings. According to this, in order to improve the color rendering properties for red, it is considered that deep red, in which the red light-emitting component is on the longer wavelength side, is preferable, and a manganese-activated germanic acid phosphor is introduced. The composition of the manganese-activated germanic acid phosphor is described, for example, in page 231 of the Phosphor Handbook (edited by the Phosphors Society of Japan, December 1987). According to this, the composition formula of this phosphor is represented by 3.5MgO.0.5MgF ₂ .GeO ₂ : Mn ⁴⁺ , and the activation amount of manganese is 1 atomic% with respect to germanium. According to the firing method, magnesium oxide, magnesium fluoride, germanium oxide, and manganese carbonate are mixed, fired in air at 1000 ° C. for several hours, mixed and pulverized, and fired in air at 1200 ° C. for more than ten hours. This phosphor material is not magnesium oxide,
Magnesium carbonate has been used because of its cost advantages. However, the manganese-activated germanic acid phosphor fired by such a method has low crystallinity and low brightness. Further, the phosphor disclosed in JP-A-11-158644 is
Since it is manufactured by a solid phase method, it has many crystal defects and is not sufficient in terms of luminance.

370 nm emitted from a light emitting diode
There are many blue light-emitting phosphors and green light-emitting phosphors that efficiently emit visible light by ultraviolet rays having wavelengths before and after. However, in particular, the red light-emitting phosphor is other blue,
There is a problem that the absorption of excitation light (ultraviolet light) having a wavelength of about 370 nm is weaker than that of the green light emitting phosphor.
In particular, when trying to reproduce emitted light having a color close to red light emission, there has been a problem that the emission luminance is significantly reduced.

[0010]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a phosphor which satisfies various phosphor properties such as luminance, and a method of manufacturing the same. .

[0011]

SUMMARY OF THE INVENTION The object of the present invention is to provide a phosphor material which emits visible light by exciting ultraviolet rays having a wavelength of 200 nm or less, and a material having light absorption in a wavelength region other than the wavelength of the visible light. A phosphor layer in which the phosphor is formed in a liquid, a distance from an arbitrary point a on the particle surface to a different point b is defined as x, and a maximum value of x is defined as a particle major axis. The ratio of the minimum value of the particle major axis to the maximum value is 0.5
１1 to １1, mainly composed of particles in the range of １1 to 、 3, containing a phosphor formed in a liquid, a fluoride containing boric acid as a matrix, and containing trivalent europium (Eu ³⁺ ) as a light emitting component. A phosphor that contains at least Gd as another cation component and generates red light when excited by ultraviolet light, the phosphor formed in a liquid, and the sulfide phosphor containing sulfur in a matrix. Phosphor coated with an oxide phosphor that emits light at substantially the same wavelength as the target phosphor, which is formed in a liquid and is a precursor represented by the following formula, which is a liquid phase synthesized precursor Phosphor, (Y, La) _1-xyz Ce _x Gd _y Tb _z (Mg, Zn, Cd) _1-p M
_{n p B 5-qs (Al} , Ga) q (X) s O 10 Formula _{AMgO · BMgF 2 · GeO 2:} xMn 4+
In expressed, phosphor precursor is synthesized liquid phase, the general formula is represented by _{(La 1-xy Eu x Sm} y) 2 O 2 S, a red-emitting phosphor precursor is synthesized liquid phase, the liquid phase A method for producing a phosphor, in which the precursor mixed by the method is put into a furnace tube, and the furnace tube is fired while rotating the furnace tube around an axis in the tube length direction. A method of manufacturing a phosphor, which is formed by a step of firing in a furnace tube while rotating the furnace tube around an axis in the tube length direction, wherein the rotation speed of the furnace tube is 10 rpm or more and 100 rpm.
The following is required: the phosphor base material and the activator material are mixed by liquid phase synthesis, and a sintering inhibitor that does not react with the phosphor base material is mixed and fired. Consisting of one or more electrically stable metal compounds.

Hereinafter, the present invention will be described. The invention according to claim 1 includes a phosphor particle that emits visible light upon excitation of ultraviolet light having a wavelength of 200 nm or less, and a material having light absorption in a wavelength region other than the wavelength of the visible light, and the phosphor is in a liquid. It is characterized in that the phosphor layer is formed.

As the light absorbing material, specifically, a material having light absorption in the green and blue wavelength regions is added to or mixed with the red light emitting phosphor layer. A material having light absorption in the red and blue wavelength regions is added to or mixed with the green light emitting phosphor layer. A material having light absorption in the red and green wavelength regions is added to or mixed with the blue light emitting phosphor layer. With these configurations, it is possible to absorb light in other wavelength ranges except for the wavelength range of light emitted by the phosphor itself. As a result, in the case of a reflective display panel, the amount of reflected external light can be reduced, and in the case of a transmissive display panel, the amount of transmitted external light can be reduced.

The addition of the material for absorbing external light is not limited to the method of directly mixing the paste into the paste for forming the phosphor layer.
Prepare a paste to which a material that absorbs external light is added separately from the phosphor paste or the phosphor paste,
A phosphor layer may be formed.

The phosphor layer can have various structures by arranging a material absorbing external light at an appropriate position in the phosphor layer. When a material that absorbs external light is uniformly applied to the surface of the phosphor particles in the phosphor layer, when the material is uniformly mixed and arranged in the phosphor layer, the material that absorbs external light is further applied to an appropriate region. There is a case where they are added at a concentration.
In particular, by arranging an appropriate thickness and concentration on the substrate side not directly irradiated with the vacuum ultraviolet ray, the contrast can be improved without affecting the luminance life of the phosphor layer.

Regardless of the position of the material that absorbs external light in the phosphor layer, to reduce the absorption of vacuum ultraviolet light, the particle size of the material that absorbs external light is determined by changing the particle diameter of the excitation light to vacuum ultraviolet light. It is effective to make the wavelength equal to or smaller than the wavelength size. This makes it possible to reduce the absorption of vacuum ultraviolet light by the material that absorbs external light, and to maintain the excitation light intensity and emission luminance of the phosphor.
The median particle size is 200 nm to 150 nm of the same size, preferably 100 nm to 70 nm of 1/2 size, more preferably 30 nm to 10 nm of 1/4 size or less.
It is. The median particle size is determined by measuring the frequency distribution of the particle size (particle size) of the phosphor particles with a particle size distribution measuring device and indicating the median value of the total particle mass in the mass-based distribution.

Furthermore, the content of the material that absorbs external light with respect to the phosphor is an important parameter for balancing the amount of absorption of vacuum ultraviolet rays and the amount of absorption of external light, and needs to be optimized. In the present invention, the concentration of a material that absorbs external light with respect to various phosphors is optimized, and is 10% by mass or less, preferably 5% by mass or less, and more preferably 3% by mass or less. If the amount is more than 10% by mass, the emission intensity of the phosphor layer becomes too low, which is not preferable.

In the present invention, Fe ₂ O _{3 is} used as a material having light absorption in green and blue wavelength regions, and ZnO / TiO ₂ / NiO is used as a material having light absorption in red and blue wavelength regions.
It is effective to use CoO / Al ₂ O ₃ as a material having light absorption in the wavelength region of / CoO, red and green. These materials can effectively reduce the reflected light amount or transmitted light amount of external light by absorbing light in other wavelength regions except for the wavelength region of light emitted by the phosphor itself. It was found that the concentration in these phosphor layers was sufficient to reduce the reflectance when the content was 5% by mass or less, regardless of the type of phosphor mixed. However, in order to minimize the decrease in luminance, it is necessary to further reduce the density.
It is preferably 2% by mass, more preferably 1% by mass, and still more preferably 0.5% by mass.

When these phosphor layers are applied to a display device using vacuum ultraviolet rays as an excitation source, especially to a display panel of a plasma display, regardless of the combination of any phosphor type and a material absorbing external light. It is important to form the phosphor layer in consideration of the above addition method, particle size and concentration. In addition, when the phosphor layer of the present invention is applied to a display panel of a plasma display or the like, not only are all phosphor layers emitting red, green, and blue lights simultaneously applied, but also two appropriate types of phosphor layers are applied. Even when applied to a combination of phosphor layers, or to any one kind of phosphor layer, a contrast improvement effect can be obtained by reducing the reflectance or the transmittance of external light. In particular, it is important to improve the contrast as the definition of a display panel of a plasma display increases. Therefore, the contrast can be easily improved by applying the phosphor layer of the present invention to a display panel of a plasma display having various partition intervals. The fluorescent film for improving the contrast is not restricted by the combination of the phosphor species and the external light absorbing material shown in the examples,
It can be applied to various material combinations, and can be used in combination with a conventional method for improving contrast in which a neutral density filter is provided on the front surface of a display panel glass. Such a combination of the simple contrast improvement methods can be applied to a display panel of a plasma display capable of realizing a large screen. Further, by applying the phosphor layer of the present invention to a display panel of a high-definition plasma display in which a partition interval formed in the display panel is 200 μm or less, it is possible to minimize a decrease in luminance and improve contrast. Can be.

A liquid phase method is used for producing the phosphor of the present invention. In some cases, the solid-phase method has to wait for each composition to be microscopically melted and diffusion mixing to occur.
The firing had to be repeated many times. This results in a considerable loss of time and energy. However, if a precursor in which elements are controlled and incorporated by a liquid phase method is used, a phosphor with high luminance 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 macroscopic crystallization does not occur, light can be emitted if the assembly of elements is controlled. For example, aluminate phosphor
Even at a temperature at which no reaction occurs in the solid phase method, light can be emitted by using a precursor of the liquid phase method.

As the liquid phase method mentioned here, general methods such as a sol-gel method, a coprecipitation method and a crystallization method can be used. As the solvent for the sol-gel method, any solvent can be used as long as the reaction raw materials are dissolved, but ethanol is preferable from the environmental point of view. The reaction initiator may be an acid or a base, but a base is more preferable from the viewpoint of the hydrolysis rate. As the type of the base, a common one such as NaOH or ammonia can be used as long as the reaction starts, but ammonia is preferable in view of the ease of removal. The method of mixing the reaction initiator may be previously added to the ground, may be added simultaneously with the raw materials, or may be added to the raw materials, but is added to the ground first to enhance uniformity. Is preferred. When a plurality of reaction raw materials are used, the order of adding the raw materials may be simultaneous or different, and an appropriate sequence can be assembled depending on the activity. In some cases, a double alkoxide may be formed.

As the solvent for the crystallization method and the coprecipitation method, any solvent can be used as long as the reaction raw materials are dissolved. However, water is preferable because the degree of supersaturation can be easily controlled. When a plurality of reaction raw materials are used, the order of adding the raw materials may be simultaneous or different, and an appropriate sequence can be assembled depending on the activity. When sulfide is produced, a compound such as sodium sulfide may be added, and hydrogen sulfide gas may be passed during firing.

In any method, the temperature, the addition speed, the stirring speed, the pH and the like may be controlled during the reaction, and ultrasonic waves may be applied during the reaction. A surfactant or a polymer may be added for controlling the particle size. After the addition of the raw materials, the liquid may be concentrated and / or aged. The obtained precipitate may be filtered, washed, and dried, may be recovered by a method such as evaporation to dryness, centrifugation, or may be washed thereafter, or may be fired simultaneously with drying. Firing may be performed in a reducing atmosphere or an oxidizing atmosphere, and can be selected as necessary.
In addition, external energy such as ultrasonic waves and collision of beads may be applied to the precipitate during the reaction and the precipitate. If light is emitted without firing, the firing step can be omitted.

The phosphor according to the fifth aspect of the present invention is represented by the following formula, and is obtained by synthesizing a precursor in a liquid phase.

(Y, La) _1-xyz Ce _x Gd _y Tb _z (Mg, Zn, Cd)
_{1-p Mn p B 5-} qs (Al, Ga) q (X) The invention according to _s O ₁₀ claim 6, formula AMgO · BMgF ₂
GeO ₂ : xMn ⁴⁺ , wherein the precursor is a liquid phase synthesized phosphor, and the invention according to claim 7 is based on the general formula (La)
Is represented by _{1-xy Eu x Sm y)} 2 O 2 S, the precursor is a liquid phase synthesized europium-samarium activated oxysulfide lanthanum red-emitting phosphor.

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.
In addition, since the sintering process proceeds sufficiently without mixing impurities such as a flux, the rate of deactivation is reduced, which is advantageous from the viewpoint of luminous efficiency.

[0027] The particle size distribution of the phosphor is important for improving the characteristics during the processing. In the invention according to claim 2, raw materials are mixed at an atomic level by the method for producing a precursor,
By promoting crystallization with energy other than heat, the particle size distribution of the resulting phosphor group can be made uniform. Specifically, when the distance from an arbitrary point a on the particle surface to a different point b is x, and the maximum value of x is defined as the particle major axis, the particle major axis (min / max) in the phosphor particle group Value is 0.5-1
, Preferably 0.6-1 and more preferably 0.7-1.

The ultraviolet-excited phosphor according to the third aspect of the present invention is a fluoride phosphor containing trivalent europium (Eu ³⁺ ) as a light-emitting component. Normal oxide-based phosphors are fired in a temperature range of 1000 to 1400 ° C. However, in the case of a phosphor containing fluoride as a main component, the firing temperature is 1100 ° C at the highest, making it easy to manufacture. is there.

The content of europium is suitably from 1 mol% to 10 mol% in terms of fluoride, preferably from 4 mol% to 8 mol%. 1 europium content
If it is less than mol%, the emission luminance is not sufficient. On the other hand, if it exceeds 10 mol%, the concentration is too high and the emission luminance decreases.

When trivalent europium is used as the light emitting element, the emission wavelength is determined by the energy order of trivalent europium and is almost constant. However, the luminance of the phosphor greatly differs depending on the elements constituting the phosphor and the ratio thereof. In the present invention, Gd is contained as a cation component together with europium so that red fluorescence having high emission luminance can be generated. Gd can be used in combination with other rare earth elements. Specifically, G
d alone, Gd and Y, Gd and La, etc. can be contained. By including a predetermined amount of Gd, the emission luminance of red light can be significantly increased.

The content of Gd is 10 mol% in terms of fluoride.
~ 60 mol% is suitable. When a rare earth element other than Gd is contained together with Gd, the total amount of Gd and the rare earth element other than Gd is 10 mol% to 60 mol% in terms of fluoride.
And the content of Gd is preferably 20 mol% or more and 40 mol% or less. Gd content is 10 mol%
If the content is less than or more than 60 mol%, the emission luminance decreases.

The host of the red phosphor of the present invention is a cation component.
With Gd or two or more rare earth elements containing Gd
Both can contain an alkaline earth metal element. G
dF _ThreeTo replace part of the metal with an alkaline earth metal element
This results in higher brightness. Alkaline earth metal element is C
One, two or more of a, Sr, and Ba are suitable.
The content is 20 mol% or more and 45 mol or less in terms of fluoride.
Appropriate. This content is less than 20 mol%
If it exceeds 45 mol%, the light emission luminance is reduced.

[0033] The fluoride phosphor of the present invention according to claim 3 contains boric acid. The phosphor absorbs the irradiated ultraviolet rays into the inside of the base material, and emits light (energy conversion) as a fluorescent color according to the energy order of the light emitting element to emit light. Therefore, as the base material of the phosphor, a compound that easily absorbs ultraviolet rays is preferable, and a compound having a large number of oxygen is usually suitably used. The phosphor of the present invention uses the above-mentioned fluoride containing boric acid as its base. The content of boric acid is 20 mol% or more and 40
Molar% or less is appropriate. When the content of boric acid is out of the above range, the emission luminance is low.

According to a fourth aspect of the present invention, an oxide phosphor whose emission wavelength is close to that of the sulfide phosphor is adhered to the surface of the sulfide phosphor containing sulfur in the matrix. In the deposition method, the oxide phosphor may be physically deposited, or the surface of the sulfide phosphor may be oxidized. As a method of physically attaching, for example, a sulfide phosphor is mixed in a solvent and sufficiently stirred by a stirrer to form a suspension A. A suspension B of the oxide phosphor is prepared in the same manner. The suspension A and the suspension B are mixed, sufficiently stirred with a stirrer, filtered by suction, and dried in air, so that the powder of the oxide phosphor is coated on the surface of the sulfide phosphor. The deposited red phosphor is obtained.

The particle size of the oxide phosphor is preferably sufficiently smaller than the particle size of the sulfide phosphor, and is preferably one tenth or less.

There is no problem if the solvent does not react with the sulfide phosphor and the oxide phosphor, and pure water is sufficient. However, alcohol such as ethanol may be used. The larger the amount of the solvent, the better.
It is preferably at least ml. Further, the longer the stirring time, the better, and it is preferable to perform stirring for 30 minutes or more. Further, the temperature at the time of drying is preferably low, so that the sulfide phosphor and the oxide phosphor do not react,
100 ° C to 300 ° C is preferred.

As a method for oxidizing the surface, for example, the sulfide phosphor is put in a quartz boat. While maintaining the tubular electric furnace at a constant temperature, a quartz boat containing the sulfide phosphor is inserted into the furnace tube, and passed through a high-temperature portion, whereby the surface of the sulfide phosphor is oxidized and the oxide phosphor is removed. A phosphor having a film formed thereon is obtained.

When the sulfide phosphor is a europium-activated yttrium oxysulfide phosphor, the temperature of the electric furnace is 7 ° C.
It is 00 ° C or higher. If the temperature is lower than 700 ° C., the oxidation reaction does not occur so much, and if the temperature is too high, the luminance decreases. Therefore, 800 to 1000 ° C. is most preferable. It should be noted that the heating rate and the cooling rate may be any rates.
The atmosphere in the electric furnace may be an oxidizing atmosphere, and may be an air atmosphere, a mixed gas of oxygen and nitrogen, or a mixed gas of oxygen and a rare gas. The time required for the sulfide phosphor to pass through the highest temperature portion varies depending on the particle size, but is preferably 5 minutes to 30 minutes, more preferably 10 minutes to 20 minutes.
When the sulfide phosphor is heated while being stirred by an external stirring means such as a stirring blade, a coating of the oxide phosphor can be more uniformly formed.

When the sulfide phosphor is placed in the furnace tube and heated while moving the powder of the sulfide phosphor by moving the furnace tube, the oxide phosphor film can be more uniformly formed. When the furnace tube is rotated about the longitudinal axis of the tube, the rotation speed is preferably 100 rpm or less. Further, the rotation direction is not a fixed direction, but may be reversed halfway.

The sulfide phosphor may be heated while blowing a gas by an external means. The blowing gas is
Any oxidizing gas may be used, and examples thereof include air, a mixed gas of oxygen and nitrogen, and a mixed gas of oxygen and a rare gas. The flow rate of the gas to be blown varies depending on the size of the furnace tube and the amount of the sulfide phosphor, but is preferably 50 ml / min or more when the diameter of the furnace tube is 10 cm.

The invention according to claims 8 to 10 uses an apparatus for firing the precursor while rotating the furnace tube around the axis in the tube length direction during firing, wherein the furnace tube is rotated by 5 r.
pm to 200 rpm, preferably 10 rpm to 100 r
It is desirable to rotate at a speed of pm. If it is less than 10 rpm, a sufficient stirring effect may not be obtained,
If it exceeds 100 rpm, the raw material sticks to the side of the furnace tube due to centrifugal force, and it may be difficult to obtain a sufficient stirring effect. Further, the furnace tube must be made of a material having extremely low reactivity with the phosphor material, and is preferably made of alumina.

Further, a solid having extremely low reactivity with the phosphor raw material may be put in the furnace tube. As the solid, beads are preferable, and the material is preferably alumina or zirconia. A stirring spring made of a material having extremely low reactivity with the phosphor raw material may be inserted into the furnace tube, and the raw material may be agitated by rotating the stirring spring. The material of the stirring spring is preferably alumina.

The rotation direction of the furnace tube may be reversed in a fixed direction or at regular time intervals. In particular, the reversal improves the stirring effect.

According to an eleventh aspect of the present invention, a phosphor base material and an activator material are mixed by liquid phase synthesis, and a sintering inhibitor which does not react with the phosphor base material is mixed and fired.

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, so that unreacted raw materials are reduced. In particular, how to incorporate the activator poses a problem, but it is desirable that 70% or more, preferably 80% or more, more preferably 90% or more of the added activator material contribute to the reaction. As a result, the amount of the activator added can be reduced. The activator content of the phosphor according to any one of claims 5 to 7 is preferably 0.03 mol% or less, more preferably 0.025 mol%, and still more preferably 0.02 mol% of the crystal matrix.
ol% or less. For example, when activating Eu to Ba ₂ SiO ₄ , 0.035 mol% is required in the conventional method, but 0.01 mol% is sufficient in the liquid phase method. This is due to effects such as reliable incorporation of Eu and delocalization.
In this case, the element abundance ratio (%) is Eu / (Ba + Si
When expressed by (+ O + Eu) × 100, the conventional method is 0.5% and the liquid phase method is 0.14%. This is especially important in terms of cost.

It is preferable that the mixing mass ratio of the sintering inhibitor added during firing to the phosphor base material is 1 to 100%.

According to a twelfth aspect of the present invention, in the invention according to the eleventh aspect, the sintering inhibitor is a metal compound, such as metal oxides such as aluminum oxide, silicon oxide and zirconium oxide, silicon nitride, aluminum nitride and the like. And at least one kind of metal compounds that are chemically stable at high temperatures, such as nitrides, silicon carbide, tungsten carbide, and tantalum carbide. These materials are stable and easy to handle, and can easily provide a phosphor with high brightness and small particle size.

As the sintering inhibitor used in the present invention, firing conditions (temperature, temperature,
It is desirable that the material does not react with the phosphor base material under the conditions such as time and atmosphere. Such sintering inhibitors are described above.

If the firing temperature is too high, the sintering inhibitor may decompose or react. Therefore, for example, ZnS and A
The firing temperature should not exceed 1500 ° C. for the combination of l ₂ O ₃ and 13 for the combination of ZnS and SiO _2.
Should not exceed 00 ° C. In addition, in order to reduce direct contact between the base materials, the average particle size of the sintering inhibitor is desirably equal to or smaller than the average particle size of the base materials. If the particle size ratio is too large, the effect of suppressing grain growth decreases, making it difficult to reduce the size of the particles,
There is an optimal value. The mass ratio of the sintering inhibitor to the base material has an optimum range in order to effectively reduce the contact between the base materials. If the mass ratio is too small, the amount is insufficient and the base material does not have the effect of the inhibitor, and the base material easily comes into contact with the particles, and if the mass ratio is too large, the sintering inhibitor remains on the phosphor surface and cannot be separated, resulting in poor brightness. Lower.

The base material used in the present invention is not limited as long as it does not react with the sintering inhibitor. The present invention is not limited to electroluminescent lamps, but may be any composition such as cathode ray tubes and fluorescent display tubes. Of the present invention. The flux, activator raw material, and co-activator raw material used in the present invention are not particularly limited, and general materials can be used.

By mixing the sintering inhibitor of the present invention with a phosphor base material and firing the mixture, a phosphor having a small particle size can be obtained. Although the reason is not clear, in the conventional method, many phosphor precursor particles are dissolved in flux or the like that has become a liquid phase by firing, so that the chance of contact between the particles increases, and the phosphor particles grow into larger phosphor particles. Therefore, in the present invention, the fine particles of the sintering inhibitor (for example, aluminum oxide) fill the gaps between the precursor particles and hinder the contact between the precursor particles. It seems that they do not grow.

In the europium / samarium-activated lanthanum oxysulfide phosphor, the atomic ratio (x) of europium (Eu) in the general formula is more preferably in the range of 0.03 to 0.08. Further, the atomic ratio (y) of samarium (Sm) in the general formula is 0.001 to 0.0.
More preferably, it is in the range of 1. Further, 30 mol% or less of La may be replaced with at least one element of Y and Gd. Also, Y and Gd for La
More preferably, the substitution amount of at least one of the elements is 5 to 20 mol%.

Here, Eu (Europium) acts as an activator (activator) for increasing the luminous efficiency of the phosphor,
Atomic ratio x with respect to La (lanthanum) is 0.01 to 0.1.
5 are added. If the addition ratio is less than 0.01, the luminance is significantly reduced and the effect of improving the luminous efficiency is small. on the other hand,
When the addition ratio exceeds 0.15, coloring is likely to occur,
Due to the concentration quenching, the luminance is remarkably reduced, and the luminous efficiency of the phosphor is rather hindered. A more preferable atomic ratio x of Eu is in the range of 0.03 to 0.08.

Sm (samarium) has an effect of shifting the excitation spectrum wavelength of the phosphor to a longer wavelength side in addition to acting as an activator.
It is added at a ratio of 0.0001 to 0.03. When the addition ratio is less than 0.0001, the shift effect is insufficient, while when the addition ratio exceeds 0.03, the luminous efficiency of the phosphor is similarly inhibited. The more preferable atomic ratio y of Sm is in the range of 0.001 to 0.01.

The red light-emitting phosphor having the above composition range has a peak wavelength in the excitation spectrum distribution of 360 to 380 nm.
And emits red light efficiently by the ultraviolet light for excitation of the LED lamp.
Yttrium (Y) used as a partial replacement of La
And gadolinium (Gd) have the effect of increasing the emission energy in the red region by forming a solid solution in the phosphor, and the substitution amount with La is set to 30 mol% or less.
If the substitution amount exceeds 30 mol%, the crystal distortion cannot be ignored, and the emission intensity becomes insufficient. A more preferable substitution amount is 5 to 20 mol%.
Range.

That is, according to the red light-emitting phosphor having the above structure, the predetermined amount of Sm is added and the excitation spectrum wavelength is changed to L.
Since the wavelength is shifted to the ED excitation ultraviolet wavelength side, the wavelength 37
Excitation ultraviolet light of about 0 nm can be efficiently absorbed and converted into red light, and the emission luminance in the red region can be greatly increased.

[0057]

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

(Examples according to claims 1 to 4) Example 1 Production of red phosphor layer <Synthesis of (Y, Gd) BO ₃ : Eu> Triisopropoxide yttrium: triisopropoxide gadolinium =
1: 1 0.03 mol / L isopropanol solution 30
0.004 europium acetylacetonate in 0 ml
mol is dissolved and added dropwise to 300 ml of a 1: 1 solution of isopropanol: water adjusted to pH 11 with ammonia.
After concentrating the solution 5 times, a 0.03 mol / l boric acid solution 30
Add 0 ml and ripen at 60 ° C. for 10 hours. The obtained precipitate was filtered, dried and calcined at 1000 ° C. for 2 hours in the air to obtain (Y, Gd) BO ₃ : Eu (RED-liquid 0). Particle long axis ratio 0.71, average spherical particle diameter 0.89 μm
Was a white powder.

Each of yttrium oxide, gadolinium oxide, europium oxide and boric acid was 0.1 mol, 0.1 mol and 0.1 mol, respectively.
1 mol, 0.35 mol, and 0.1 mol were weighed, mixed well in a mortar, and then calcined at 1200 ° C. for 2 hours in the air to obtain (Y, Gd) BO ₃ : Eu (RED-solid 0). It was a white powder having a particle long axis ratio of 3.1 and a sphere-equivalent average particle size of 3.93 μm.

The center particle diameter is about 1/100 of vacuum ultraviolet rays (147 nm and 172 nm) having a wavelength shorter than 200 nm, which is the excitation light.
4 wavelengths of 50 nm or less (10 to 30 nm) of (Fe
₂ O ₃ ) Fine particles were prepared. These fine particles of the external light absorbing material were weighed and mixed at 0.5% by mass with respect to the phosphor particles to obtain RED-liquid 1, RED-solid 1, and RED-solid 1.
Liquid 0, RED-solid 0, RED-liquid 1, RED-solid 1 and the vehicle were mixed at a ratio of 40:60, mixed and stirred well to prepare a phosphor paste containing a light absorbing material, and applied to a glass surface.

Preparation of Green Phosphor Layer <Synthesis of Zn ₂ SiO ₄ : Mn> 300 ml of a 0.03 mol / L ethanol solution of tetraethoxysilane and 300 ml of a 0.03 mol / L aqueous solution of zinc acetate: manganese acetate = 9: 1 were prepared. After mixing, the mixture is added dropwise to 300 ml of a 1: 1 ethanol: water solution adjusted to pH 11 with ammonia. After concentrating the solution 5 times, dilute it 3 times with water,
Aged for hours. The resulting precipitate is filtered, dried and then dried.
Baked in the air for 2 hours at a temperature of Zn ₂ SiO ₄ : Mn (GRE
EN-Liquid 0) was obtained. It was a white powder having a particle major axis ratio of 0.91 and a sphere-converted average particle size of 0.93 μm.

0.1 mol, 0.1 mol, 0.01 mol of zinc oxide, silane oxide and manganese oxide, respectively.
After weighing and mixing well in a mortar, the mixture was calcined at 1200 ° C. for 2 hours in the air to obtain Zn ₂ SiO ₄ : Mn (GREEN-solid 0). Particle long axis ratio: 4.0, sphere-equivalent average particle diameter: 4.1
It was a 2 μm white powder.

The center particle diameter is about 1/100 of vacuum ultraviolet rays (147 nm and 172 nm) having a wavelength shorter than 200 nm, which is the excitation light.
Four wavelengths of 50 nm or less (10 to 30 nm) of (Zn
O / TiO ₂ / NiO / CoO) fine particles were prepared. These external light absorbing material fine particles were weighed and mixed at 0.5% by mass with respect to the phosphor particles, respectively, and GREEN-liquid 1, G
REEN-solid 1 was obtained, and GREEN-liquid 0, GREE
N-solid 0, GREEN-liquid 1, GREEN-solid 1 and the vehicle were mixed at a ratio of 40:60, mixed and stirred well to prepare a phosphor paste containing a light absorbing material, and applied to a glass surface.

Preparation of Blue Phosphor Layer <Synthesis of Ba ₂ Si ₂ Al ₂ O ₈ : Eu> 0.033 mol of aluminum tributoxide, 0.0015 mol of europium acetylacetonate and 300 ml of butanol
And reflux for 16 hours. This solution and tetraethoxysilane (0.033 mol) in butanol solution 250m
The solution dissolved in 1 is added dropwise to 259 ml of a 1: 1 ethanol: water solution adjusted to pH 11 with ammonia. After concentrating the solution 5 times, 500 ml of 0.033 mol / L aqueous solution of barium nitrate was added, and the mixture was aged at 60 ° C. for 10 hours. The obtained precipitate was filtered and dried, and then calcined at 1000 ° C. for 2 hours in a reducing atmosphere to obtain Ba ₂ Si ₂ Al ₂ O ₈ : Eu (BLUE-solution 0). The particle major axis ratio was 0.74, and the sphere-converted average particle diameter was 0.
The powder was 86 μm white powder.

Barium oxide, silane oxide, aluminum oxide,
Europium oxide was 0.05 mol and 0.1 mol respectively.
After weighing, mixing well in a mortar and firing at 1200 ° C. for 2 hours in a reducing atmosphere, Ba ₂ Si ₂ Al ₂ O ₈ : Eu (BLUE-solid 0) was obtained. Particle long axis ratio 3.01, average sphere-equivalent particle size 3.76μ
m of white powder.

The center particle diameter is about 1/100 of vacuum ultraviolet rays (147 nm and 172 nm) having a wavelength shorter than 200 nm which is the excitation light.
Four wavelengths of 50 nm or less (10 to 30 nm) of (Co)
O / Al ₂ O ₃ ) fine particles were prepared. These external light absorbing material fine particles were weighed and mixed at 0.5% by mass with respect to the phosphor particles, respectively, to obtain BLUE-Liquid 1 and BLUE-Solid 1.
Further, BLUE-Liquid 0, BLUE-Solid 0, BLUE-Liquid 1, BLUE-Solid 1 and the vehicle were mixed at a ratio of 40:60, mixed and stirred well to prepare a phosphor paste containing a light-absorbing material. Applied.

(Evaluation of brightness) Brightness meter MCPD manufactured by Otsuka Electronics Co., Ltd.
614 nm at an excitation wavelength of 147 nm using -7000
(Red), 525 nm (Green), 466 nm
The luminance at the emission wavelength of (Blue) was measured, and the evaluation was made based on the relative luminance with respect to the sample of 0 as 100.

(Evaluation of reflectivity) Reflector MCP manufactured by Otsuka Electronics Co., Ltd.
Using D-2000, the reflectance (%) at 400 nm to 700 nm was measured.

Table 1 shows the results.

[0070]

[Table 1]

As shown in Table 1, the contrast is higher when the light absorbing material is contained. Furthermore, it was found that the reflectance of the phosphor synthesized by the liquid phase method can be kept low while the brightness is high. This is thought to be due to the effect that the surface of the particles is smoothed by the precursor synthesis in the liquid phase, and unnecessary scattering and the like are suppressed. In addition, since the particles are monodisperse particles, there is an effect that the filling rate when forming the phosphor layer is high and the luminance is increased.

Example 2 <Synthesis of Y ₂ O ₂ S: Eu ³⁺ > 0.03 mol / L isopropanol solution of yttrium triisopropoxide yttrium 3
Europium acetylacetonate 0.00 in 00 ml
4mol dissolved solution and 0.03m of sodium sulfide
ol / L aqueous solution (150 ml) was adjusted to pH 11 with ammonia to 300 ml of a 1: 1 solution of isopropanol: water.
To be dropped. After concentrating the solution 5 times, dilute 3 times with water,
Aged at 0 ° C. for 10 hours. The obtained precipitate was filtered, dried, and then fired in a crucible at 1000 ° C. for 2 hours to obtain Y ₂ O ₂ S: E.
u3 ⁺ (REDS-liquid 0) was obtained.

Each of yttrium oxide, sulfur solid, and europium oxide was 0.2 mol, 0.1 mol, and 0.1 mol, respectively.
After weighing 35 mol and mixing well in a mortar, 1200 ° C
For 2 hours in a crucible at (Y, Gd) BO ₃ : Eu
(REDS-solid 0) was obtained.

Each phosphor was fired at 900 ° C. for 1 hour in the air to form an oxide film.
Solid 1 was obtained.

The luminance was evaluated in the same manner as in Example 1, and the luminance after 200 hours was also evaluated. Table 2 shows the results.

[0076]

[Table 2]

As shown in Table 2, the phosphor of the present invention has a small average particle size and a high luminance. Example _{3 <0.34BaF 2 · 0.26GdF 2 ·} 0.35B
Synthesis of ₂ O ₃ : 0.06 Eu> Ammonium fluoride 0.8
was dissolved in 600 ml of water, 1 L aqueous solution of 0.34 mol of barium nitrate and 0.26 mol of gadolinium nitrate, 1 L of 0.7 mol / L boric acid aqueous solution, and 50 ml of ethanol solution of 0.06 mol of europium acetylacetonate were added and mixed. The resulting solution was evaporated to dryness and calcined at 1000 ° C. for 2 hours in the air to obtain an F-liquid.

0.6 mol of ammonium fluoride, 0.34 mol of barium oxide, 0.26 mol of gadolinium oxide
1, boric acid 0.7 mol, europium oxide 0.06 m
After weighing and mixing well in a mortar,
Firing in the air for an hour gave F-solids.

Similarly, the luminance of the phosphor itself was evaluated at an excitation wavelength of 172 nm and an emission wavelength of 614 nm.

Table 3 shows the results.

[0081]

[Table 3]

As shown in Table 3, according to the present invention, a phosphor having a small average particle size and high luminance was produced.

[0083] (Example according to the invention of claim 5 to 12) Example 4 Sample _{1 H 3 BO 3: 12.748g,} CeO 2: 1.291g,
Gd ₂ O ₃ : 5.439 g, MgCO ₃ : 3.342 g
(0.05 molar excess), MnCO ₃ : 0.4311 g,
Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.1 S was prepared by using Al ₂ O ₃ : 0.1911 g and SiO ₂ : 0.113 g as raw materials.
i _0.05 B _4.85 O ₁₀ was synthesized using the solid phase method.

The raw materials are mixed well, introduced into the furnace at room temperature and heated to 560 ° C. in a nitrogen atmosphere. After a holding time of 30 minutes, calcination is carried out at 1015 ° C. for 4 hours under reducing conditions. The compound thus obtained showed an emission band with a maximum at 626 nm (by UV excitation at 254 nm). FIG. 1 shows the emission spectrum.

[0085] Sample _{2 H 3 BO 3: 12.748g,} Ce 2 (CO 3) 3 · 8H
_{2 O: 4.532g, Gd (NO} 3) 3 · 6H 2 O: 13.
548 g, MgCO ₃ : 3.342 g, MnCO ₃ : 0.
Gd _0.8 Ce _0.2 Mg _0.9 Mn _0.1 Al _0.1 Si was obtained by using 4311 g, AlCl ₃ .6H ₂ O: 0.9029 g, and tetraethoxysilane (TEOS): 0.3749 g as raw materials.
_0.05 B _4.85 O ₁₀ was synthesized using a liquid phase method.

A 0.1 mol / L solution of each raw material was prepared (the solvent was ethanol only for TEOS, and the others were pure water) and mixed. The resulting solution is evaporated to dryness to produce the desired precursor, introduced into a furnace at room temperature and heated to 560 ° C. in a nitrogen atmosphere. After a holding time of 30 minutes, 101 under reducing conditions
The firing is performed at 5 ° C. for 4 hours. The compound thus obtained is 625 nm (by UV excitation at 254 nm).
The emission band having the maximum was shown.

When the luminances of the obtained samples 1 and 2 were compared (excitation of 254 nm ultraviolet light and emission of 626 nm), sample 2
Indicates 127 as a relative luminance with sample 1 being 100. Therefore, according to the present invention, a phosphor having higher luminance can be realized.

Sample 3: Magnesium oxide: 3.5 mol, magnesium fluoride:
Using 0.5 mol, germanium oxide: 1.0 mol, and manganese carbonate: 0.003 mol as raw materials, 3.5 Mg
O.0.5MgF ₂ .GeO ₂ : 0.003Mn ⁴⁺ was synthesized using a solid phase method.

The raw materials were mixed well, placed in an alumina crucible with a lid, introduced into a furnace at room temperature, and 400 ° C. in an air atmosphere.
/ Hour and a preliminary firing at 1000 ° C. for 2 hours. After further crushing using a mortar, 1200 ° C
For 2 hours. Further, the fired product is ground using a mortar. The compound thus obtained is (254 nm
An emission band with a maximum of 655 nm was obtained (by UV excitation).

Sample 4 MgCO_Three: 294.35 g, MgF_Two: 31.1505
g, Ge (OC_TwoH_Five) _Four: 252.85 g, MnCO_Three:
Using 0.344838 g as a raw material, 3.5MgO.
5MgF_Two・ GeO_Two: 0.003 Mn⁴⁺Using the liquid phase method
And synthesized.

A 0.1 mol / L solution of each raw material was prepared (the solvent was ethanol only for Ge (OC ₂ H ₅ ) ₄ , and the others were pure water) and mixed. The obtained solution is evaporated to dryness to prepare a precursor of the target substance, placed in an alumina crucible with a lid, introduced into a furnace at room temperature, and heated at a rate of 400 ° C./hour in an air atmosphere to 1000 ° C. For 2 hours. Furthermore, after pulverizing using a mortar, main firing is performed at 1200 ° C. for 2 hours. Further, the fired product is ground using a mortar. The compound thus obtained exhibited an emission band with a maximum at 656 nm (by excitation with UV light at 254 nm).

The brightness of Samples 3 and 4 obtained was compared (excitation of 254 nm ultraviolet light and emission of 655 nm).
Indicates 138 in relative luminance with sample 3 being 100. Therefore, according to the present invention, a phosphor having higher luminance can be realized.

Sample 5 La ₂ O ₃ : 229.7 g, Eu ₂ O ₃ : 16.01 g, S
m ₂ O ₃ : 2.64 g, S: 61.38 g, Na ₂ CO ₃ :
Using 86.94 g and 24.84 g of Li ₃ PO ₄ as raw materials, (La _0.93 Eu _0.06 Sm _0.01 ) ₂ O ₂ S was synthesized by a solid phase method.

The raw materials were mixed well, placed in an alumina crucible with a lid, introduced into a furnace at room temperature and 1250 in an air atmosphere.
It was calcined at a temperature of ° C. for 4 hours. Further, the fired product is ground using a mortar. The compound thus obtained is (380 nm
An emission band with a maximum of 625 nm (by UV excitation).

Sample 6 La ₂ (CO ₃ ) ₃ .8H ₂ O: 848.7636 g, Eu
_{(NO 3) 3 · 6H 2} O: 40.503156g, Sm
_{(NO 3) 3 · 6H 2} O: 6.60615g, Na 2 S: 1
Using 49.381958 g as a raw material, (La _0.93 Eu
_0.06 Sm _0.01 ) ₂ O ₂ S was synthesized using a liquid phase method.

A 0.1 mol / L solution of each raw material was prepared (all solvents were pure water) and mixed. The obtained solution was evaporated to dryness to prepare a target precursor, and further, Na ₂ CO ₃ 86.94.
g, 24.84 g of Li ₃ PO ₄ were mixed, placed in an alumina crucible with a lid, introduced into a furnace at room temperature, and 12 g in an air atmosphere.
It was baked at a temperature of 50 ° C. for 4 hours. Further, the fired product is ground using a mortar. The compound thus obtained is (380
An emission band with a maximum of 625 nm (by UV excitation of nm).

When the brightness of the obtained Samples 5 and 6 was compared (380 nm ultraviolet excitation, 655 nm emission), Sample 6
Indicates 124 as a relative luminance with respect to the sample 5 as 100. Therefore, according to the present invention, a phosphor having higher luminance can be realized.

Sample 7 A phosphor precursor synthesized by a liquid phase method in the same manner as in Sample 4 was placed in an alumina furnace tube, heated at a rate of 400 ° C./hour in an air atmosphere, and heated at 1000 ° C. for 2 hours. Preliminary firing is performed.
FIG. 2 shows a conceptual diagram of the electric furnace used for firing. Core tube 1
Is tilted at an angle of about 40 degrees from the horizontal and rotated at a speed of 30 rpm about an axis in the pipe length direction. Further, after pulverizing using a mortar, the mixture is put into an alumina furnace tube, and while the furnace tube 1 is rotated by the above-described method, 400 ° C. /
The temperature is raised at a temperature raising rate of time, and main firing is performed at 1200 ° C. for 2 hours. In addition, 2 is a heat insulating material, and 3 is a heater wire. Further, the fired product is ground using a mortar. The compound thus obtained is 656 (by UV excitation at 254 nm).
An emission band having a maximum of nm was shown.

When the brightness of the obtained sample 7 was measured (excitation of ultraviolet light at 254 nm and emission of light of 655 nm), the relative brightness of the sample 7 was 152 with the sample 3 being 100. In the present invention, a phosphor having higher luminance was realized by rotating the furnace tube and baking while stirring the raw material.

[0100] Sample _{8 H 3 BO 3: 12.748g,} CeO 2: 1.291g,
Gd ₂ O ₃ : 5.439 g, MgCO ₃ : 3.342 g
(0.05 molar excess), MnCO ₃ : 0.4311 g,
Al ₂ O ₃ : 0.1911 g, SiO ₂ : 0.113 g,
Aluminum oxide C (sintering inhibitor, manufactured by Aerosil): Gd _0.8 Ce _0.2 Mg _0.9 Mn using 1 g as a raw material
_0.1 Al _0.1 Si _0.05 B _4.85 O ₁₀ was synthesized using a solid phase method.

The raw materials are mixed well, introduced into the furnace at room temperature and heated to 560 ° C. in a nitrogen atmosphere. After a holding time of 30 minutes, calcination is carried out at 1015 ° C. for 4 hours under reducing conditions. The compound thus obtained showed an emission band with a maximum at 626 nm (by UV excitation at 254 nm).

[0102] Sample _{9 H 3 BO 3: 12.748g,} Ce 2 (CO 3) 3 · 8H
_{2 O: 4.532g, Gd (NO} 3) 3 · 6H 2 O: 13.
548 g, MgCO ₃ : 3.342 g, MnCO ₃ : 0.
_{4311g, AlCl 3 · 6H 2 O} : 0.9029g, T
EOS: Gd _0.8 Ce _0.2 using 0.3749 g as a raw material
Mg _0.9 Mn _0.1 Al _0.1 Si _0.05 B _4.85 O ₁₀ was synthesized using a liquid phase method.

A 0.1 mol / L solution of each raw material was prepared (the solvent was ethanol only for TEOS, and the others were pure water) and mixed. The obtained solution is evaporated to dryness to prepare a target precursor, mixed with 1 g of aluminum oxide C (a sintering inhibitor, manufactured by Aerosil), introduced into a furnace at room temperature, and heated to 560 ° C. in a nitrogen atmosphere. . After a holding time of 30 minutes, calcination is carried out at 1015 ° C. for 4 hours under reducing conditions. The compound thus obtained exhibited an emission band with a maximum of 625 nm (by UV excitation at 254 nm).

Table 4 shows the results of measuring the luminance and the particle size distribution of Samples 1, 8, and 9.

[0105]

[Table 4]

Thus, it is understood that a phosphor having a small particle size and higher luminance can be realized in the present invention.

[0107]

According to the present invention, a phosphor excellent in luminance can be obtained.

[Brief description of the drawings]

FIG. 1 shows an emission spectrum of Sample 1 of Example 4.

FIG. 2 is a conceptual diagram of an electric furnace for firing.

[Explanation of symbols]

 1 Furnace tube 2 Insulation material 3 Heater wire

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) C09K 11/64 CPR C09K 11/64 CPR 11/66 CPT 11/66 CPT 11/78 CPK 11/78 CPK 11 / 80 CPK 11/80 CPK CQD CQD 11/81 CQD 11/81 CQD 11/82 CQD 11/82 CQD 11/84 CPD 11/84 CPD 11/85 CPL 11/85 CPLF Term (Reference) 4H001 CA01 CA02 CA04 CA05 CA07 XA05 XA08 XA09 XA12 XA13 XA14 XA16 XA25 XA30 XA39 XA56 XA57 XA58 XA62 XA63 XA64 YA25 YA63

Claims (12)

[Claims] 1. A phosphor comprising a phosphor particle that emits visible light upon excitation of ultraviolet light having a wavelength of 200 nm or less and a material having light absorption in a wavelength region other than the wavelength of the visible light, wherein the phosphor is formed in a liquid. A phosphor layer, characterized in that: 2. A different point b from an arbitrary point a on the particle surface
When the maximum value of x is defined as the particle major axis, and the ratio of the minimum value of the particle major axis to the maximum value is in the range of 0.5 to 1 in the particle group, And a phosphor formed in a liquid. 3. A fluoride containing boric acid as a base,
A phosphor that contains trivalent europium (Eu ³⁺ ) as a light-emitting component, contains at least Gd as another cation component, and generates red light when excited by ultraviolet light, and is formed in a liquid. Phosphor. 4. A phosphor comprising a sulfide phosphor containing sulfur in a matrix and an oxide phosphor emitting at substantially the same wavelength as the sulfide phosphor adhered to the surface of the sulfide phosphor. A phosphor characterized in that: 5. A phosphor represented by the following formula, wherein the precursor is obtained by liquid phase synthesis. (Y, La) _1-xyz Ce _x Gd _y Tb _z (Mg, Zn, Cd) _1-p Mn _p B
_{5-qs (Al, Ga)} q (X) s O 10 wherein, X is Si, Ge, P, Zr, V, Nb, Ta,
W or the sum of a plurality of the above elements, p, q, s,
x, y and z are optionally ≤1. ] 6. The general formula: AMgO.BMgF ₂ .G
eO ₂ : a phosphor represented by xMn ⁴⁺ [A + B = ^4, 0.5 ≦ B ≦ 1.0], wherein the precursor is synthesized in a liquid phase. 7. A general formula _{(La 1-xy Eu x Sm} y) 2
O ₂ S [0.01 ≦ x ≦ 0.15, 0.0001 ≦ y ≦ 0.0
3) A red light-emitting phosphor, wherein the precursor is synthesized in a liquid phase. 8. A method for producing a phosphor, comprising: placing a precursor mixed by a liquid phase method in a furnace tube; and firing the furnace tube while rotating the furnace tube around an axis in the tube length direction. 9. A process in which a precursor obtained by mixing the phosphor according to claim 5 by a liquid phase method is placed in a furnace tube, and firing is performed while rotating the furnace tube around an axis in the tube length direction. A method for producing a phosphor, comprising: 10. The rotation speed of the reactor core tube is 10 rpm or more and 1
The rotation speed is not more than 00 rpm.
3. The method for producing a phosphor according to item 1. 11. A phosphor base material and an activator raw material are mixed by liquid phase synthesis, and a sintering inhibitor that does not react with the phosphor base material is mixed and fired.
Or the method for producing a phosphor according to item 10. 12. The method for producing a phosphor according to claim 11, wherein the sintering inhibitor comprises at least one kind of a metal compound which is chemically stable at a high temperature.