JP2001131544A - Yellow-green emitting luminous body of heat-resistance, water resistance, high luminance and long luminescent persistency and production thereof - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a yellow-green emitting luminous body having improved initial emission luminance and afterglow time. SOLUTION: This yellow-green emitting luminous body has heat resistance, water resistance, high luminance and long after-glowing properties and the following composition formula: Sr1-n-m-k-qE'nEumLnkYq)OrAl2O3:BxFy (where 0<=n<=0.1, 0<m<=0, 0<k<=0.1, 0<=q<=0.05, 1<=r<=1.50, 0<=x<=0.1, 0<y<=0.1, E' is one or more kinds of elements selected from Mn, Zn, Bi, Ca, Mg, Ba; Ln is one or more kinds of lanthanoid elements) and is indexed with the monoclinic crystal system and mainly comprises a fluorine-containing strontium aluminate salt.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a strontium aluminate phosphor containing fluorine and having excellent heat and water resistance and a high luminance and a long afterglow yellow-green luminescent color, and a method for producing the same. An object of the present invention is to provide a strontium aluminate phosphor which can be fired at a temperature as low as 1000 ° C., has excellent productivity, has high initial luminance and afterglow luminance, and is chemically stable.

[0002]

2. Description of the Related Art Phosphors are excited by external energy such as electron beams, X-rays, ultraviolet rays, sunlight, fluorescent lights, etc., and emit light for a long time after excitation is stopped. Can be done. Conventionally, as a sulfide-based phosphor, blue-emitting (Ca, Sr) S: Bi and yellow-green-emitting ZnS:
Cu and (Zn, Cd) S: Cu which emit red light are known. These have low afterglow luminance, have the problem that they are decomposed by ultraviolet rays under high-temperature and high-humidity conditions and become black, and the afterglow luminance is significantly deteriorated. Use was limited.

In recent years, aluminate phosphors that are chemically more stable and have a long afterglow time that can be visually confirmed in the dark (Japanese Patent No. 2543825, US Pat. No. 5,37)
No. 6,303 and JP-A-8-151574, silicate phosphors (JP-A-9-194833), aluminum silicate phosphors (JP-A-9-238966), and the like.

As the aluminate phosphor, SrAl ₂ O ₄ : Eu, Dy which emits yellow-green light and SrAl ₂ O ₄ : Er, which emits blue-green light are used.
₄ Al ₁₄ O ₂₅ : Eu, Dy, SrAl ₄ O
₇ : Initial (for example, 1 after excitation) compared to Eu, Dy, etc.
However, it is pointed out that, although the emission luminance of (ii) is high, afterglow and weather resistance, particularly water resistance, are inferior. Further, JP-A-8-15
Japanese Patent No. 1574 discloses that phosphorus contains heat- and water-resistant yellow-green light-emitting SrAl ₂ O ₄ : Eu, Dy phosphors that are improved by phosphoric acid, and afterglow brightness at 600 ° C. for 30 minutes. Has a retention of 76.6% before calcining and has been reported to have 49.1% after stirring in water for 72 hours.

[0005]

SUMMARY OF THE INVENTION The present inventor has set forth the above Sr.
Al ₂ O ₄ : stabilization of the crystal structure of the Eu, Dy phosphor,
As a result of intensive studies on components that can achieve high heat resistance and water resistance, and achieve high luminance and long afterglow, by crystal growth, low temperature firing, defect control, etc.
In particular, by simultaneously containing boron and fluorine, the emission luminance one minute after excitation is stopped can be increased up to about 1.7 times and the emission luminance one hour later can be increased 3.1 times, and high heat and water resistance can be obtained. It has been found that a phosphorescent material having a property can be mass-produced at low cost at a lower firing temperature than before.

The present invention is based on this finding, and the basic problem to be solved is that the yellow-green SrAl ₂ O ₄ : Eu, Dy phosphor having a high initial light emission luminance has a higher initial light emission luminance than that of the phosphor. An object of the present invention is to provide a yellow-green luminescent color phosphor having an improved afterglow time. Another object of the present invention is to provide a yellow-green luminous color phosphor having high heat resistance that does not deteriorate its luminous properties even when fired in the air. Another problem to be solved by the present invention is to use water-based luminous inks and applied products such as luminous paints for automobiles outdoors and underwater.
An object of the present invention is to provide a yellow-green luminous color luminous body capable of maintaining luminous characteristics for a long time.

Another object of the present invention is to enable low-temperature, short-time sintering, thereby making it possible to change from a batch-type furnace to a carrier-type tunnel furnace, facilitating mass continuous production. And a method of manufacturing the same. Another object of the present invention is to make it possible to use a heat-resistant stainless steel as a furnace material by enabling firing at a low temperature,
An object of the present invention is to provide a yellow-green luminous color phosphor that facilitates systematization for mass production with low equipment cost and a method of manufacturing the same.

[0008]

Means for Solving the Problems] yellow-green emission color phosphorescent article of the present invention to solve the above problems, a composition _{formula, (Sr 1-n-m} -k-q E 'n Eu m Ln k Y
_q ) Al ₂ O ₄ : B _x , F _y , or (Sr
_1-n-m-k- q E 'n Eu m Ln k Y q) O ·
rAl ₂ O ₃ : B _x , F _y (where 0 ≦ n ≦ 0.1 0 <m ≦ 0.05 0 <k ≦ 0.1 0 ≦ q ≦ 0.05 1 ≦ r ≦ 1.50 0 ≦ x ≦ 0.10 <y ≦ 0.1, where E ′ is Mn, Zn, Bi, Ca, M
one or more metal elements selected from the group consisting of g and Ba, Ln
Are Ce, Pr, Gd, Tb, Dy, Ho, Er, T
m, Yb, Lu), and is mainly composed of fluorine-containing strontium aluminate represented by a monoclinic system.

Further, the method for producing a yellow-green luminous color phosphor of the present invention for solving the above-mentioned problems is characterized in that the elements Sr, Al, Eu, Y, E ', Ln and B in any of the above-mentioned composition formulas are replaced by A single powder or a compound powder or a solution containing the same is weighed so as to have a composition ratio of the above formula, and the compound powder or a solution containing an F element is baked and weighed so as to have a quantity ratio of the above composition formula. As a starting material, after mixing them, the mixed powder obtained by drying and pulverization is put into a heat-resistant container, and molded or kept in a powdery state in a reducing atmosphere at 1000 ° C to 1500 ° C for 30 minutes to 2 hours. After firing,
It is characterized in that the cooled fired product is ground into a powder.

According to the yellow-green luminous color phosphor having the above structure and the method for producing the same, the conventional SrAl ₂ O ₄ : Eu,
The initial light emission luminance and afterglow time are further improved as compared with the Dy phosphor, and the ink has high heat resistance such that the phosphorescent property does not decrease even when fired in air (500 ° C. to 900 ° C.). Also, when an applied product such as a phosphorescent paint for automobiles is used outdoors or underwater, a yellow-green luminous phosphor that can maintain the phosphorescent characteristics for a long time can be obtained. Moreover, the yellow-green luminescent SrO.rAl ₂ O ₃ : Eu, D
y The phosphor is kept at low temperature for a short time (for example, 30 minutes at 1150 ° C.).
Minutes), so that a batch type furnace can be changed to a carrier type tunnel furnace, facilitating mass continuous production, and at the same time, a phosphorescent light that requires high heat resistance (oxidation resistance firing property). Fired in the air (500 ° C-9
(00 ° C.), the luminous properties are not reduced, and the luminous properties can be maintained for a long time when an applied product such as an aqueous luminous ink or a luminous paint for automobiles is used outdoors or in water.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION The heat-resistant, water-resistant, high-brightness, long-persistent yellow-green luminescent color phosphor according to the present invention is represented by the above-mentioned composition formula and is indexed by a monoclinic system and is strontium containing fluorine. It is mainly composed of an aluminate, and its yellow-green luminous color phosphor can be produced as follows.
That is, high purity (purity 99% or more) in the above composition formula
A simple substance powder or a compound powder or a solution containing the elements r, Al, Eu, Y, E ', Ln and B is weighed so as to have the above-mentioned composition ratio, and the compound powder or the solution containing the element F is fired. The starting material was weighed so as to have the composition ratio of the above composition formula, and after thoroughly mixing them, the mixed powder obtained by drying and pulverization was placed in a heat-resistant container such as ceramics, molded, Alternatively, in the state of a powder, in a reducing atmosphere at 1000 to 1500 ° C. for 30 minutes to 2
After calcination for a period of time, the cooled calcined product is pulverized into a powder to obtain a target yellow-green luminescent phosphor powder.

The luminous body provided by the present invention usually has a maximum emission intensity in the range of 510 to 520 nm,
Conventional fluorine-free SrAl ₂ O ₄ : Eu · Dy
Compared with, it has features of higher initial luminance and longer afterglow time.
In particular, by containing both boron and fluorine, the effect becomes extremely remarkable. These effects are due to Sr ₂
It is also effective for a blue or blue-green luminescent phosphor mainly containing Al ₆ O ₁₁ or other strontium aluminate. For example, in a yellow-green luminous phosphor of Sr ₂ Al ₆ O ₁₁ (no boric acid present), the sintering temperature can be reduced by containing fluorine, and the sintering temperature can be shortened (within 1 hour).
And high crystallinity, and high luminance and long afterglow characteristics can be obtained.

However, when each of the halogen elements Cl, Br, and I other than fluorine was also contained in the same production method as in the embodiment of the present invention, the effect as in the case of containing fluorine of the present invention was not obtained. Could not be obtained. As the fluorine source, NH ₄ F, SrF ₂ , LiSiF
₅ , KF, MnF ₂ , CaF ₂ , SrF ₂ , ZnF
_{2. In} addition to KTiF ₆ , any compound containing fluorine can be used. However, it is indispensable that the added fluorine forms a solid solution in the phosphor at a constant rate in the manufacturing process. , Atmosphere, heating rate, etc.) to determine what intermediate products are formed and how they affect crystal growth and the formation of defect structures. It is important to select the reaction conditions and calcination conditions, which are low, and the type of the fluorine source.

In the present invention, lithium fluoride can be strongly recommended as an optimum fluorine source. However, considering the above-mentioned requirements, it is more difficult to control production than other fluorine-containing compounds. Based on the judgment that the safety is ensured, the stability and reproducibility of the phosphor quality are high, and the reaction can be easily controlled. In the case of using lithium fluoride only in the production process described in the examples, the amount of addition is suitably 0.5 to 5% by weight of the starting material, and preferably 1 to 2% by weight. Firing temperature is 1300 ℃
At the following temperatures, the firing time is preferably within 2 hours.

When boron is added simultaneously, that is, when 0 ≦ x ≦ 0.1 in the above composition formula, the amount of fluorine added to obtain a single phase as a luminous body after firing is 0.1 mol / mol SrO. 07 mol or less. In order to obtain predetermined luminous characteristics and heat / water resistance characteristics in the obtained phosphor, the fluorine content x in the above composition formula is preferably 0.01 to 0.08 mol, and if it is more than that, a small amount of fluorine compound is used. Mixed as two phases. When fluorine is not added, the preferable addition amount of boric acid is 5 to 8 wt%, but when fluorine and boron are added simultaneously, the optimum addition amount of boric acid is 1%.
２2 wt%. When fluorine and boron are added at the same time, performance as a light storage unit with extremely high luminance and long afterglow is obtained. In addition to this light emission behavior, it has been found that there is also an effect on water resistance and heat resistance.

Hereinafter, other compositions of the phosphor according to the present invention will be sequentially described. E ′: The constituent component E ′ in the composition formula is Mn, Z
The elements n, Bi, Ca, Mg, and Ba can be used alone or in combination. The amount (molar value) of the E 'element is
0 ≦ n ≦ 0.1, preferably 0.001 ≦ n ≦ 0.0
5 range. The emission luminance decreases when Ba and Ca are used, and the emission luminance increases when Mn, Zn, Bi and Mg are used. In particular, the effect of the solid solution of Bi is great, and an appropriate charge transfer state can be formed. By forming an effective excitation relaxation process, the light emission luminance of the phosphor can be significantly improved.

Eu: The composition of the light-emitting center Eu ²⁺ is 0 <m ≦ 0.05, preferably 0.001 ≦ m ≦
A range of 0.01 is suitable. When the m value is less than 0.0001, a predetermined emission intensity cannot be obtained because the amount of ions serving as the emission center is small. If the m value exceeds 0.05, density quenching becomes visible, and the light storage characteristics are significantly deteriorated. Ln: The coactivator Ln is 0 <k ≦ 0.1, preferably
A range of 0.001 ≦ k ≦ 0.03 is suitable. In particular,
The number of moles of Dy ³⁺ has an optimum value depending on the amount of Eu added, and 1.5 times the number of moles of Eu is optimal. Dy ³⁺ and Y
^With the combined use of ³⁺ , the emission luminance and the long afterglow are improved.

The reasons why the simultaneous addition of fluorine and boron has enabled high-brightness, long afterglow, water and heat resistance and low-temperature, short-time sintering to be possible are as follows. (1) Effect of simultaneous addition; LiF, Ca
Fluorine-containing compounds such as F ₂ , NH ₄ F, and LiSiF ₅ are often used as fluxes during the firing reaction, such as alkali-containing carbonates, chlorides, borides, etc., during crystal growth, diffusion reaction, and firing reaction. There are known effects such as lowering the temperature. Usually, an amount of several wt% to 10 wt% of the reactant is used as the flux. For example, Sr
In the O.rAl ₂ O ₃ : Eu, Dy phosphor, 3 wt% to 10 wt% of boric acid is added to the starting material. It has been found that boron is partially substituted by solid solution at the Al site, and is useful for grain growth as a flux of dissolution and precipitation, and contributes to high luminance and long afterglow.

However, 51 synthesized without adding boron was used.
When boron is added to a phosphor that emits light at 0 to 520 nm, the maximum emission wavelength shifts to 490 nm. As a flux that does not change the light emission characteristics, lithium fluoride is the most suitable.
When ８8 wt% is added, the optimum firing temperature is lowered from 1500 ° C. to 1250 ° C., and a phosphorescent material having efficient light emission characteristics can be obtained in a short time. When lithium carbonate is added instead of lithium fluoride, the firing reaction temperature decreases, but the light emission characteristics deteriorate. Next, with respect to other fluorine-containing compounds, for example, NH ₄ F and LiSiF ₅ , they have a function as a flux, and although the crystallinity and the heat and water resistance are improved, the luminous characteristics as a light accumulator, in particular, a long residue. It has been found that the light properties are not as improved as lithium fluoride.

From the above conclusions, the addition of fluorine makes it possible to control the crystal growth and diffusion reaction at a low temperature, and furthermore, the Eu ²⁺ ion as a luminescence center and the Ln ^{3 +} ion of the co-activator are added to the lattice. It has been clarified that it contributes to uniform distribution and contributes to high luminance and long afterglow. FIGS. 1 to 3 show scanning electron micrographs of the fracture surface of the phosphor sample fired at 1250 ° C. for 2 hours. 1 shows a sample to which neither boron nor fluorine was added, FIG. 2 shows a sample to which fluorine was added, and FIG. 3 shows a sample to which boron and fluorine were added simultaneously. FIG.
In the sample to which 1% by weight of lithium fluoride and 1% by weight of boric acid were added, it can be seen that the crystal had a size of 3 to 10 μm, and that remarkable growth was caused as compared with the others.

(2) Lattice distortion effect: Table 1 summarizes the lattice constants and firing conditions of the monoclinic phosphor. In the same table, SrAl ₂ O ₄ contains 0%,
wt%, 3 wt% of lithium fluoride, and 1 wt% of lithium fluoride and 3% of boric acid were added, mixed, molded, and fired at 1250 ° C. for 2 hours.
AF0, SAF1, SAF3 and SABF1.
Also, Sr _0.987 Eu _0.005 Dy _0.008
Al ₂ O ₄ : B _{0 . At 041} , 0
%, 1%, 3% by weight, and 5% by weight of lithium fluoride, and calcined at 1250 ° C. for 2 hours.
0, SAEDBF1, SAEDBF3, SAEDBF5
And

The lattice constant obtained from the powder X-ray diffraction pattern is
It is supposed that the crystallinity was reduced by the solid solution substitution of fluorine, and crystal distortion was caused by the broadening of the peak. However, all of them can obtain high luminance and long afterglow.

[0023]

[Table 1]

1 wt% lithium fluoride was added, and 125
The sample fired at 0 ° C. for 2 hours is a single-phase SrAl
It was composed of ₂ O ₄ and, as a result of chemical analysis, was found to contain 0.058 mol of fluorine. On the other hand, SrF ₂ was mixed in the sample after adding 5 wt% of lithium fluoride and firing at 1250 ° C. for 2 hours. On the other hand,
Further re-calcination yielded a single phase having the same peak as SrAl ₂ O ₄ . From the above results, F ⁻ of the added lithium fluoride was changed to O 2 of the phosphorescent lattice.
It is conceivable that the substitution with ^2- and the reduction of the concentration of O ² -kira center resulted in the distortion of a part of the lattice and the improvement of luminance.

(3) Charge balance effect: By adding boron and fluorine simultaneously, SrO.rAl ₂ O ₃ :
The Eu, Dy phosphor can realize a more activated matrix, and a more activated Eu ²⁺ emission center and a uniform dispersion of the Ln ³⁺ coactivator. As a result, effective energy transfer is performed, which contributes to high-luminance light emission performance. Considering reactively, in the presence of fluorine and boron, SrCO ₃ → SrO
The reaction of + CO ₂ } is further promoted, and the generated SrO is rich in reactivity, so that the reaction with Al ₂ O ₃ can be completed in a short time. Furthermore, the presence of fluorine is Eu
It contributes to ²⁺ stability.

(4) Stabilizing effect of oxygen deficiency; lattice instability caused by oxygen ion deficiency is trapped not by hydroxide ions but by fluorine ions, so that dissolution of phosphor particles is prevented and heat resistance and water resistance are improved. It is considered that this contributes to improvement.

(5) Light emission behavior; 1). All of the starting materials added with 1 wt% to 5 wt% of lithium fluoride have a maximum excitation wavelength of 205 nm.
２０８208 nm and the maximum emission wavelength is 512 nm〜517 n
m. Also, with the increase in the amount of lithium fluoride added,
It was observed that the half-value width gradually increased from 75 nm to 80 nm, and the initial light emission luminance was lowered as the crystallinity was lowered. Loss of fluorine during the firing process (AlF ₃ ↑,
HF ↑) or the formation of SrF ₂ or the like as a by-product, the composition of the phosphor is considered to be slightly shifted (non-stoichiometric ratio), and the influence of fluorine and boron taken into the lattice. Improves crystallinity, but especially 4%
The above addition lowers the luminance.

2). S without adding activator and co-activator
In rAl ₂ O ₄ : F, long light emission and afterglow were observed. SrCO ₃ and Al ₂ O ₃ were weighed at an equimolar ratio, and lithium fluoride was added in an amount of 0%, 1% by weight, 3% by weight, and 5% by weight.
wt% and the mixed powder added was molded into φ20, and 1250
At 2 ° C. for 2 hours in an argon gas containing 3% H ₂ ,
Further, the sample (SABF) to which 1 wt% of lithium fluoride and 1 wt% of boric acid were simultaneously added was calcined under the same conditions. As a result, the sample without lithium fluoride had almost no change in volume after calcination, and was irradiated with an ultraviolet lamp. No light emission was observed below. On the other hand, the other samples to which lithium fluoride was added contracted considerably to exhibit a dense tissue, exhibited blue-green fluorescence under ultraviolet excitation, and observed afterglow after the excitation was stopped. In particular, the SABF sample had a high luminous intensity and a long persistence. When Eu ²⁺ , Dy ³⁺ or the like is activated in such a high-efficiency light-emitting composition, excellent light storage properties are exhibited.

In the present invention, by simultaneous addition of fluorine and boron,
It is characterized in that a luminous body which has remarkable crystal growth and can stably maintain high luminance and long afterglow even with fine powder can be obtained. Luminance and afterglow of conventional phosphors are affected by the particle size of the powder,
When the particles are fine, the emission luminance and the afterglow remarkably deteriorate. For example, comparing a phosphor having an average particle size of 10 μm with a phosphorescent material having a mean particle size of 30 μm, the luminance at 3 minutes after excitation is 60: 100, but the sample of the present invention has an extremely small influence of particle size of 95: 100. Furthermore, in the present invention, by the simultaneous addition of fluorine or fluorine and boron, the hardness of the sintered body is lower than that of a conventional sintered body to which only boric acid is added, so that the pulverization step is easy and the productivity is increased. There is also a feature.

Further, it can be fired at a lower temperature, and has a great feature that contamination from a metal container or the like is small when molding by mixing a phosphorescent powder and a resin, and that deterioration of luminance can be prevented. Furthermore, since low-temperature sintering is possible,
A tunnel type continuous furnace can be used from the current batch type furnace, and heat-resistant stainless steel can be used as the furnace material. Becomes easier.

[0031]

The present invention will be described in more detail with reference to the following examples. Prior to the description, methods for measuring afterglow luminance, a heat resistance test and a water resistance test in the following examples will be described.

First, the method of measuring the afterglow luminance is as follows. The powder of the luminous body of the example or the comparative example is uniformly mixed with a polyester resin or the like, and the weight ratio of the luminous body: polyester resin is 1: 2, and the thickness is 2.5 mm.
And dried, and this is used as a sample for measuring the change with time of the emission intensity. The measurement was performed on a measurement sample placed in a dark room for 24 hours after light blocking using a 15 W white fluorescent lamp for 100 hours.
After irradiating the sample from the vertical distance of 15 mm for 15 minutes, the change with time of the emission luminance is measured. Tables 2 and 3 show the measurement results.

The method of the heat resistance test is as follows. 30
5 g of a phosphorescent powder having a size of 0 μm or less was weighed, placed in an alumina crucible, and oxidized and fired in an electric furnace at 800 ° C. and 900 ° C. for 1 hour in the air. A luminance maintenance ratio with respect to the afterglow luminance is obtained. Table 4 shows the measurement results. The luminous body obtained in the present invention still exhibited a luminance maintenance ratio of 70% or more even when heated at 900 ° C. in the atmosphere. In addition, 10mm ×
A luminous body molded into a size of 10 mm x 20 mm
Oxidation calcination was carried out at 0 ° C. for 180 minutes in the air, and in this case also, the retention was about 43%.

The method of the water resistance test is as follows. 30
200 ml of pure water is put into a 0 ml beaker, 10 g of a phosphor powder of 300 μ under is added, impregnated for 24 hours, then dried and the afterglow luminance is measured, and the luminance maintenance ratio with respect to the afterglow luminance before water treatment is obtained. . Table 5 shows the measurement results.

Example 1 Sr _0.987 Eu
_0.005 Dy _0.008 Al ₂ O ₄ : B _0.04
Such that the ratio of the chemical composition formula of ₁ F _0.058, as the starting material powder (purity 99.9%), SrCO
₃ , Al ₂ O ₃ , Eu ₂ O ₃ , Dy ₂ O ₃ , H
₃ BO ₃ and LiF were converted into SrCO ₃ = 0.987 × 147.63 = 145.7, respectively.
1 g Al ₂ O ₃ = 1 × 101.96 = 101.96 g Eu ₂ O ₃ = 0.005 × 1/2 × 3511.93 =
0.88 g Dy ₂ O ₃ = 0.008 × 1/2 × 373.000 =
1.49 g H ₃ BO ₃ = 0.041 × 61.83 = 2.54 g LiF = 0.098 × 25.94 = 2.54 g Each was accurately weighed and wet-mixed with pure water for 24 hours in a ball mill. went.

Next, the mixture was dried at 140 ° C. to obtain a mixed powder. This mixed powder was packed in an alumina heat-resistant container and fired at 1100 ° C. for 1 hour in an argon gas containing 3% of hydrogen using an electric furnace of a stainless steel furnace tube. After cooling, the collected sample was crushed to obtain the phosphor powder of the present invention. As a result of chemical analysis, the fluorine content was 0.058 mol. The powder X-ray diffraction method was able to index a single-phase monoclinic system. Further, according to SEM observation, it was observed that the present phosphor showed high crystallinity despite the low-temperature and short-time firing step.

FIG. 4 shows an emission spectrum when excited by ultraviolet light of 260 nm. This means that the maximum emission wavelength is 512
It is a yellow-green luminescent color phosphor near nm. In order to measure the time change of the luminescence intensity, 1.25 g of the phosphor powder having a particle diameter of 300 μm or less and 2.5 g of polyester resin are weighed, uniformly mixed, and then molded into a sheet having a thickness of 2.5 mm. Then, a dried product was prepared, and the change in emission intensity after the excitation was stopped was measured by the method described above. The results are shown in the column of Example 1 in Table 2. Table 4 shows the results of the heat resistance test.

[Examples 2 to 18] Specific examples of Examples 2 to 18
Table 2 shows typical chemical composition formulas and firing conditions. These practices
For the example, as in Example 1, the necessary starting material powder
SrCO₃ , CaCO ₃ , Al₂ O₃ , Eu₂ O
₃ , Dy₂ O₃ , Y₂ O₃ , Sm₂ O₃, Tm₂
 O₃ , H₃ BO₃ , LiF, MgO, MnO, Zn
O, Bi₂ O ₃ Is weighed, and is weighed with a ball mill.
After performing pure water wet mixing for 4 hours, drying at 140 ° C.
A mixed powder was obtained. Put this in a carbon crucible,
Baking in a 3% hydrogen-containing nitrogen gas
Done. Each sample was crushed after cooling and 300 μm
Particles having the following sizes are sieved and classified, and stored according to the present invention.
I got a light body.

Tables 2 and 3 show the change over time (afterglow luminance) of the light emission luminance of these examples and the comparative examples described below, and Tables 4 and 5 show the luminance maintenance rates in the heat and water resistance tests. . In the heat resistance test by heat treatment at 800 ° C. for 1 hour in the air, as shown in the heat resistance test results in Table 4, the luminous bodies of the respective examples of the present invention maintain high brightness and stop excitation.
A minute later, the retention rate was 83% or more before the heat treatment.
On the other hand, all the samples used as comparative examples turned white, and the luminance retention ratio was 1% or less. Regarding water resistance, the luminous body of the present invention shows a maintenance rate of 85% or more,
The sample of the comparative example had a retention rate of about 6.2%.

[0040]

[Table 2]

[0041]

[Table 3]

[0042]

[Table 4]

[0043]

[Table 5]

While the conventional aluminate phosphor has an additive composition which essentially requires boron, the present invention contains only fluorine as shown in Examples 17 and 18. It has high light emission performance.

Comparative Example 1 Sr _0.987 Eu
_0.005 Dy _0.008 Al ₂ O ₄ : B _0.04
The phosphorescent article of Comparative Example 1 containing no fluorine having ₁ chemical composition, was obtained as follows. The following starting material powders having a purity of 99.9% were weighed, mixed by the method described in Example 1, and prepared under the firing conditions of 1400 ° C. for 2 hours as shown in Table 2. _{SrCO 3 145.71g Al 2 O 3 101.96g} Eu 2 O 3 0.88g Dy 2 O 3 1.49g H 3 BO 3 2.54g

Tables 2 to 5 show the luminous properties and the results of the water resistance / heat resistance tests of the obtained samples. As shown in Table 3, the sample of Comparative Example 1 had lower luminance and afterglow than that of Example 4 of the present invention, and was further heated at 800 ° C. in air as shown in Table 4. Then, it became white and lost its light emitting performance. Further, as shown in Table 5, in the water resistance test in which the water treatment was performed for 24 hours, the afterglow luminance after the excitation was stopped was low, and the maintenance ratio was about 6.2%.

Comparative Example 2 Sr _0.975 Eu
The phosphor of Comparative Example 2, which has a chemical composition of _0.01 Dy _0.015 Al ₂ O ₄ and does not contain fluorine and boron,
Using the same method as in Example 1, as shown in Table 2,
It was produced by firing at 0 ° C. for 2 hours. As shown in Table 2, the luminous body of Comparative Example 2 had significantly reduced emission luminance and afterglow.

[0048]

According to the present invention described in detail above, water resistance and
A fluorine-containing yellow-green luminescent color phosphor having excellent heat resistance, extremely high initial luminance and long afterglow characteristics can be obtained. Further, compared to the conventional SrAl ₂ O ₄ : Eu, Dy, the inclusion of fluorine and boron facilitates pulverization and makes it easier to obtain a powder product, and also helps to prevent contamination of metal powder. further,
The manufacturing method of the present invention maintains a high luminance and has a process suitable for producing a fine powdery phosphor, and as in the prior art,
High-temperature and long-time sintering conditions can be set to lower temperature and short-time, and there are favorable conditions for mass production such as energy saving and productivity improvement.

[Brief description of the drawings]

FIG. 1 is a scanning electron micrograph instead of a drawing of a fractured surface of a fired phosphor sample when fluorine and boron are not added.

FIG. 2 is a scanning electron micrograph instead of a drawing of a fractured surface of a fired phosphor sample when only fluorine is added.

FIG. 3 is a scanning electron micrograph as a substitute for a drawing of a fractured surface of a fired phosphorescent sample when both fluorine and boron are added.

FIG. 4 is a view showing an emission spectrum (excitation wavelength: 260 nm, emission wavelength: 512 nm) of the phosphor obtained in Example 1.

Continued on front page F-term (reference) 4H001 CF02 XA08 XA12 XA13 XA20 XA25 XA30 XA38 XA39 XA56 XA58 XA59 XA63 XA64 XA65 XA66 XA67 XA68 XA69 XA70 XA71 XA83 YA05 YA09

Claims (3)

[Claims] 1. A composition _{formula, (Sr 1-n-m} -k-q E 'n Eu m Ln k Y
_q ) Al ₂ O ₄ : B _x , F _y (where 0 ≦ n ≦ 0.1 0 <m ≦ 0.05 0 <k ≦ 0.1 0 ≦ q ≦ 0.05 0 ≦ x ≦ 0.1 0 <y ≦ 0.1, where E ′ is Mn, Zn, Bi, Ca, M
one or more metal elements selected from the group consisting of g and Ba, Ln
Are Ce, Pr, Gd, Tb, Dy, Ho, Er, T
m, Yb, Lu, one or more lanthanoid elements selected from the group consisting of fluorinated strontium aluminate represented by a monoclinic system.
Water-resistant, high-brightness, long-lasting yellow-green luminescent phosphor. 2. A composition _{formula, (Sr 1-n-m} -k-q E 'n Eu m Ln k Y
_q ) O · rAl ₂ O ₃ : B _x , F _y (where 0 ≦ n ≦ 0.1 0 <m ≦ 0.05 0 <k ≦ 0.10 ≦ q ≦ 0.05 1 ≦ r ≦ 1 .500 0 ≦ x ≦ 0.1 0 <y ≦ 0.1, where E ′ is Mn, Zn, Bi, Ca, M
one or more metal elements selected from the group consisting of g and Ba, Ln
Are Ce, Pr, Gd, Tb, Dy, Ho, Er, T
m, Yb, Lu, one or more lanthanoid elements selected from the group consisting of fluorinated strontium aluminate represented by a monoclinic system.
Water-resistant, high-brightness, long-lasting yellow-green luminescent phosphor. 3. Elements of Sr, Al, Eu, Y, E ', Ln and B (where E' is Mn, Zn, Bi, Ca, Mg, B
Ln is one or more metal elements selected from the group of a.
e, Pr, Gd, Tb, Dy, Ho, Er, Tm, Y
b, and simple substance powder or a compound powder or a solution containing a lanthanoid element) of one or more kinds selected from the group of _{Lu, (Sr 1-n-} m-k-q E 'n Eu m Ln k Y
_q ) Al ₂ O ₄ : B _x , F _y , or (Sr
_1-n-m-k- q E 'n Eu m Ln k Y q) O ·
rAl ₂ O ₃ : B _x , F _y (where 0 ≦ n ≦ 0.1 0 <m ≦ 0.05 0 <k ≦ 0.1 0 ≦ q ≦ 0.05 1 ≦ r ≦ 1.50 0 ≦ x ≦ 0.10 <y ≦ 0.1) while weighing so that the composition ratio of the composition formula is satisfied, and baking the compound powder or solution containing the F element to obtain the composition ratio of the above composition formula. The starting material is used as a starting material, and after mixing them, the mixed powder obtained by drying and pulverizing is placed in a heat-resistant container, and molded or kept in a powdery state in a reducing atmosphere at 1000 ° C to 1500 ° C for 30 minutes. After baking for ~ 2 hours, the cooled calcined product is pulverized into a powder to produce a fluorinated strontium aluminate heat / water resistant / high brightness / long afterglow yellow-green luminous phosphor. Law.