JP2001271064A - Luminous fluorescent substance - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a luminous fluorescent substance having a long-time afterglow characteristic and also being chemically stable, and excellent in long-term lightfastness. SOLUTION: This luminous fluorescent substance features comprising a compound represented by the formula: MAl2O4 (wherein M is at least one of metallic elements selected from the group consisting of calcium, strontium and barium) in a state of host crystal, and being mixed with europium as an activator in an amount of 0.001-10 mol% based on the quantity of a metallic element represented by M and with at least one of elements selected from the group consisting of manganese, tin and bismuth as a coactivator in an amount of 0.001-10 mol% based on the quantity of a metallic element represented by M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphorescent phosphor, and more particularly to a novel phosphorescent phosphor having excellent light resistance and having an extremely long afterglow characteristic, which can be used mainly for nighttime display indoors and outdoors. Things.

[0002]

2. Description of the Related Art Generally, the afterglow time of a phosphor is extremely short.
When the external stimulus is stopped, its light emission is attenuated immediately,
In rare cases, after stimulating with ultraviolet rays or the like, after stimulating is stopped, afterglow is observed with the naked eye for a considerably long time (several tens of minutes to several hours), and these are distinguished from ordinary phosphors. It is called a phosphorescent phosphor or phosphor.

The phosphorescent phosphor is CaS: Bi.
(Violet-blue emission), CaSrS: Bi (blue emission), Zn
Sulfide phosphors such as S: Cu (green light emission) and ZnCdS: Cu (yellow to orange light emission) are known, and any of these sulfide phosphors is chemically unstable or light-fast. There are many problems in practical use such as poor performance. Zinc sulfide phosphorescent phosphor (ZnS: C) currently used exclusively in the market
Also, u) is difficult to use in applications where it is exposed to direct sunlight outdoors, especially in the presence of moisture, because it is photodegraded by ultraviolet rays and blackened or its brightness is reduced. Its use, such as indoor night display, has been limited.

Even when this zinc sulfide-based phosphor is used in a luminous timepiece, the afterglow time during which the time can be recognized by the naked eye is about 30 minutes to about 2 hours. At present, it has been necessary to use a self-luminous luminous paint which emits constantly by adding a radioactive substance and stimulating with the energy.

[0005]

In view of the above-mentioned situation, the present inventor has far longer afterglow characteristics than commercially available sulfide-based phosphors, and furthermore, has a chemical An object of the present invention is to provide a phosphorescent phosphor that is stable and has excellent light resistance over a long period of time.

[0006]

As a novel phosphorescent phosphor material completely different from the conventionally known sulfide phosphor, attention has been paid to the alkaline earth metal aluminate activated with europium and the like. As a result of this experiment, this phosphorescent phosphor material has a much longer afterglow characteristic than a commercially available sulfide phosphor, and furthermore, it is chemically oxidized because it is an oxide phosphor. It can be confirmed that it is stable and excellent in light resistance, can solve all the conventional problems, and can be applied to various uses as a luminous paint or pigment that can be seen all night without containing radioactivity. It has become clear that it is possible to provide an afterglow phosphorescent substance.

[0007] As the above-mentioned phosphorescent phosphor, MAl ₂ O ₄ Wherein M is a compound comprising at least one metal element selected from the group consisting of calcium, strontium and barium as a mother crystal, in which europium is used as an activator, and a mole relative to the metal element represented by M 0.001% in%
Not less than 10% and at least one element of the group consisting of manganese, tin and bismuth as a co-activator in an amount of 0.001% or more by mol% based on the metal element represented by M.
It is characterized by adding 10% or less.

In synthesizing these phosphorescent phosphors, for example, boric acid can be added as a flux in the range of 1 to 10% by weight. Where the addition amount is 1% by weight
If it is less than the above, the flux effect will be lost, and if it exceeds 10% by weight, it will solidify, and subsequent pulverization and classification work will be difficult.

[0009]

EXAMPLES The following description is directed to MAl ₂ O ₄ Examples of the present invention represented by the following formulas will be sequentially described for cases where the type of metal element (M), the concentration of europium as an activator, or the type and concentration of a co-activator are variously changed. First, a phosphorescent phosphor using strontium as a metal element (M) and europium as an activator but not using a coactivator will be described as Example 1. Embodiment 1 FIG. SrAl ₂ O ₄ : Synthesis of Eu phosphor and its characteristics Sample 1- (1) Europium oxide (Eu ₂ ) was used as an activator for 146.1 g (0.99 mol) of strontium carbonate and 102 g (1 mol) of alumina. O ₃ ⁾ 1.76 g (0.005
Mol) and further add, for example, boric acid as a flux.
After adding 5 g (0.08 mol) and mixing thoroughly using a ball mill, the sample was placed in a stream of nitrogen-hydrogen mixed gas (97: 3) (flow rate: 0.1 liter / minute) using an electric furnace.
C. for 1 hour. Thereafter, the mixture was cooled to room temperature over about 1 hour, and the obtained compound powder was sieved and classified, and one that passed through 100 mesh was defined as phosphor sample 1- (1).

FIG. 1 shows the result of analyzing the crystal structure of the synthesized phosphor by XRD (X-ray diffraction). The phosphor obtained from the characteristic of the diffraction peak is SrAl ₂ O ₄ It became clear that it had a spinel structure of FIG. 2 shows the excitation spectrum of the present phosphor and the emission spectrum of afterglow after the stimulation was stopped.

From the figure, it is clear that the emission spectrum is green emission having a peak wavelength of about 520 nm.
Next, this SrAl ₂ O ₄ : A ZnS: Cu phosphorescent phosphor which emits green light with the afterglow characteristic of a Eu phosphor as a commercial product (manufactured by Nemoto Specialty Chemical Co., Ltd .: product name: GSS, emission peak wavelength: 530)
3 and Table 2 show the results measured in comparison with the afterglow characteristics of (nm).

The measurement of the afterglow characteristic was performed using 0.05 g of phosphor powder.
Is weighed into an aluminum sample dish with an inner diameter of 8 mm (sample thickness:
0.1g / cm2), store in the dark for about 15 hours to reduce afterglow
After erasing, D₆₅200 lux brightness with standard light source
And stimulate the afterglow with a photomultiplier tube
It was measured by a luminance measuring device. Clear from FIG.
Thus, the SrAl according to the present invention_Two O_Four : Of Eu phosphor
The afterglow is extremely large and its attenuation is slow.
With the ZnS: Cu phosphorescent phosphor,
It turns out that it becomes large. Also, in the figure,
Luminous intensity level (about 0.3 mCd / m2
(Corresponding to degrees) is indicated by a broken line._Two O_Four : E
Even after about 24 hours, the light emission is
Presumed to be 15 hours after the actual stimulation
This SrAl _Two O_Four : Eu phosphor was observed with the naked eye
However, the afterglow was sufficiently confirmed.

Sample 1- (1) in Table 2 shows the afterglow intensity at 10 minutes, 30 minutes and 100 minutes after the cessation of stimulation,
S: Relative to the intensity of the Cu phosphorescent phosphor.
From this table it can be seen that SrAl ₂ according to the invention O ₄ : Afterglow luminance of the Eu phosphor after 10 minutes was 2.9 of the ZnS: Cu phosphorescent phosphor.
It can be seen that it is twice and 17 times after 100 minutes. Further, according to the present invention, SrAl ₂ O ₄ : FIG. 4 shows the results of investigating the thermoluminescence characteristics (glow curve) from room temperature to 250 ° C. when light stimulating the Eu phosphor using a TLD reader (KYOKKO TLD-2000 system). From the figure, it can be seen that the thermal emission of this phosphor is composed of three glow peaks of about 40 ° C., 90 ° C., and 130 ° C., and the peak at about 130 ° C. is the main glow peak. ZnS: Cu shown by a broken line in the figure
In view of the fact that the main glow peak of the phosphorescent phosphor is about 40 ° C., the SrAl ₂ O ₄ : It is considered that the deep trap level corresponding to the high temperature of 50 ° C. or higher of the Eu phosphor increases the time constant of afterglow and contributes to the long-term light storage characteristics.

Samples 1- (2) to (7) Next, in the same manner as described above, SrAl ₂ having a compounding ratio shown in Table 1 in which the concentration of europium was changed. O ₄ : Eu phosphor samples (samples 1- (2) to (7)) were prepared.

[0015]

[Table 1]

The results of the examination of the afterglow characteristics of the samples 1- (2) to (7) are shown in Table 2 together with the results of the examination of the afterglow characteristics of the sample 1- (1). From Table 2, it can be seen that when the addition amount of Eu is in the range of 0.0025 to 0.05 mol, the afterglow characteristics are superior to that of the ZnS: Cu phosphorescent phosphor including the luminance after 10 minutes. Understand. However, when the amount of Eu added is 0.
Even in the case of 00001 mol, or even 0.1 mol, 30 minutes or more after the stimulation is stopped,
It can also be seen that the phosphor has a higher luminance than the ZnS: Cu phosphorescent phosphor.

Also, since Eu is expensive, it is not meaningful to make Eu 0.1 mol (10 mol%) or more in consideration of economical efficiency and deterioration of afterglow characteristics due to concentration quenching. Become. Conversely, judging from the afterglow characteristics, Eu was 0.00001 mol (0.001 mol%).
And 0.00005 mol (0.005 mol%), the luminance after 10 minutes is lower than that of the ZnS: Cu phosphorescent phosphor, but after 30 minutes or more after stopping the stimulation, the ZnS: Cu phosphorescence is obtained. Since a luminance higher than that of the luminescent phosphor is obtained, the effect of adding Eu used as an activator is apparent.

Further, SrAl ₂ O ₄ : Since the Eu phosphor is an oxide-based phosphor, it is chemically more stable than the conventional sulfide-based phosphorescent phosphor and has excellent light resistance (see Tables 24 and 25).

[0019]

[Table 2]

Next, a luminous phosphor using strontium as the metal element (M), europium as an activator, and dysprosium as a coactivator will be described as a second embodiment. Embodiment 2. FIG. SrAl ₂ O ₄ : Synthesis of Eu and Dy phosphors and their characteristics Sample 2- (1) Europium oxide (Eu ₂ ) was used as an activator for 144.6 g (0.98 mol) of strontium carbonate and 102 g (1 mol) of alumina. O ^₃₎ in 1.76g (0 .005
Mol) and dysprosium oxide (Dy ₂ O ^₃₎ at 1.87 g (0.005 mol) was added, further, for example, as boric acid 5 g (0.08 mol) was added flux were mixed thoroughly using a ball mill, the sample using an electric furnace nitrogen - hydrogen mixtures It was baked at 1300 ° C. for 1 hour in a gas (97: 3) stream (flow rate: 0.1 liter per minute). Thereafter, the mixture was cooled to room temperature over about 1 hour, and the obtained compound powder was sieved and classified, and the mixture which passed through 100 mesh was defined as phosphor sample 2- (1).

The afterglow characteristic of this phosphor is measured in the same manner as described above.
The results of the investigation are shown in FIG. 5 and sample 2- (1) in Table 4.
Was. As is clear from FIG. 5, the SrAl according to the present invention_Two
O_Four : Afterglow luminance of the Eu and Dy phosphors, especially the initial stage of the afterglow
The luminance at the time is extremely higher than that of the ZnS: Cu phosphorescent phosphor.
High and the time constant of the decay is large,
It can be seen that this is a high-luminance phosphorescent phosphor. Shown in the figure
Visible afterglow intensity level and this SrAl _Two O_Four : E
Due to the afterglow characteristics of u and Dy phosphors, their emission
Light can be identified.

Table 4 shows that 10 minutes, 30 minutes, 100 minutes after stimulation.
The afterglow intensity after minutes is compared to the intensity of the ZnS: Cu phosphorescent phosphor.
The relative values of SrA according to the present invention are shown in the table.
l_Two O_Four : Afterglow luminance of Eu, Dy phosphor is Z after 10 minutes.
nS: 12.5 times of Cu phosphorescent phosphor, and after 100 minutes
It turns out that it is 37 times. Furthermore, SrAl according to the present invention
_Two O_Four : 2 from room temperature when Eu, Dy phosphor was photostimulated
Investigation of thermoluminescence characteristics (glow curve) up to 50 ° C
The results are shown in FIG. From FIGS. 6 and 4, the co-activator
Of main luminescence due to the action of Dy
It can be seen that the working temperature changed from 130 ° C. to 90 ° C.
Large light emission from the trap level corresponding to the temperature of 90 ° C.
But SrAl_Two O_Four : Afterglow compared to Eu phosphor
This is considered to be a cause of high luminance at the initial stage.

Samples 2- (2) to (7) Next, in the same manner as described above, the dysprosium concentration was changed and SrAl ₂ was added at the compounding ratio shown in Table 3. O ₄ : Eu, D
y phosphor samples (samples 2- (2) to (7)) were prepared.

[0024]

[Table 3]

The results of the examination of the afterglow characteristics of the samples 2- (2) to (7) are shown in Table 4 together with the results of the examination of the afterglow characteristics of the sample 2- (1). From Table 4, it can be seen that D as a co-activator
Based on the fact that the addition amount of y is far superior to the ZnS: Cu luminous phosphor, including the luminance after 10 minutes, it is understood that the optimum amount is 0.0025 to 0.05 mol. However, even if the addition amount of Dy is 0.00001 mol, the luminance becomes larger than that of the ZnS: Cu phosphorescent phosphor after 30 minutes or more after the stimulation is stopped. The effect of adding Eu and Dy used as co-activators is clear. In addition, since Dy is expensive, considering the economic efficiency and the deterioration of the afterglow characteristic due to the concentration quenching, Dy is 0.1 mol (1
(0 mol%) or more is meaningless.

It should be noted that SrAl ₂ O ₄ : Since the Eu and Dy phosphors are oxide-based, they are chemically more stable than the conventional sulfide phosphorescent phosphors and have excellent light resistance (see Tables 24 and 25). .

[0027]

[Table 4]

Next, a phosphorescent phosphor using strontium as a metal element (M), europium as an activator, and neodymium as a coactivator will be described as a third embodiment. Embodiment 3 FIG. SrAl ₂ O ₄ : Synthesis of Eu and Nd phosphors and their properties Samples 3- (1) to (7) SrAl ₂ having a blending ratio shown in Table 5 in which the neodymium concentration was changed by the same method as described above. O ₄ : Eu, Nd-based phosphor samples (samples 3- (1) to (7)) were prepared.

[0029]

[Table 5]

The results of investigating the afterglow characteristics of these samples 3- (1) to (7) are shown in Table 6.

[0031]

[Table 6]

As shown in Table 6, when the amount of Nd added as a coactivator is in the range of 0.0025 to 0.10 mol, 1
It can be seen that the afterglow characteristics are superior to that of the ZnS: Cu phosphorescent phosphor including the luminance after 0 minutes. However, even when the amount of Nd added is 0.00001 mol, 6 hours after the stimulation is stopped.
By passing about 0 minutes, the phosphor has a higher luminance than the ZnS: Cu phosphorescent phosphor.
The effect of adding Eu and Nd used as activators and coactivators is clear. In addition, since Nd is expensive, it is meaningless to set Nd to 0.1 mol (10 mol%) or more in consideration of economy and deterioration of afterglow characteristics due to concentration quenching.

Note that SrAl ₂ O ₄ : Since Eu and Nd phosphors are oxide-based, they are chemically more stable and more excellent in light resistance than conventional sulfide-based phosphorescent phosphors (see Tables 24 and 25). . Further, according to the present invention, SrAl ₂ O ₄ : Thermoluminescence characteristics from room temperature to 250 ° C. when glowing Eu and Nd phosphors (glow curve)
Is shown in FIG. 7 for the results obtained by examining Sample 3- (4). From the figure, it can be seen that the main glow peak temperature of thermal emission of the phosphor to which Nd is added as a co-activator is about 50 ° C.

Next, strontium is used as a metal element (M), europium is used as an activator, and lanthanum, cerium, praseodymium, samarium, gadolinium, terbium, holmium, erbium, thulium, ytterbium, lutetium are used as co-activators. A phosphorescent phosphor using any of the elements of manganese, tin, and bismuth will be described as Example 4.

Here, the activator and each co-activator show a high residual when added about 0.005 mol each to the metal element (M) from the case where europium, neodymium or dysprosium is used. Considering that light brightness can be obtained, the Eu concentration of the activator is 0.5 mol%.
(0.005 mol), the concentration of the co-activator 0.5 mol% (0.
005 mol) of the sample. Embodiment 4. FIG. SrAl ₂ O ₄ : Effect of other co-activator on Eu-based phosphor As described above, lanthanum, cerium, praseodymium, samarium, gadolinium, terbium,
Holmium, erbium, thulium, ytterbium,
Table 7 shows the results of investigating the afterglow characteristics of the phosphor samples to which lutetium, manganese, tin, and bismuth were added.

As is clear from Table 7, any of the SrAl ₂ O _{3 was} compared with the afterglow characteristics of the commercially available ZnS: Cu phosphor used as a standard. O ₄ : It can be seen that the Eu-based phosphor sample also has a sufficiently practical level, since the afterglow characteristics are improved after a long time of 30 minutes to 100 minutes or more after the stimulation is stopped. Note that SrAl ₂ O ₄ : Since the Eu-based phosphor is an oxide-based phosphor, it is chemically more stable than the conventional sulfide-based phosphorescent phosphor and has excellent light resistance (see Tables 24 and 25).

[0037]

[Table 7]

Next, calcium is used as the metal element (M) and europium is used as an activator, but a phosphorescent phosphor in the case where no co-activator is used, and calcium is used as a metal element and europium is used as an activator. ,
When using at least one element of the group consisting of lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin, bismuth as a co-activator,
This will be described as a fifth embodiment. Embodiment 5 FIG. CaAl ₂ O ₄ : Synthesis of Eu-based phosphorescent phosphor and its properties Europium oxide (Eu ₂₎ is used as an activator for reagent grade calcium carbonate and alumina. O ₃ ⁾ , and lanthanum, as a co-activator,
Cerium, praseodymium, neodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin or bismuth For example, after adding 5 g (0.08 mol) of boric acid and mixing them sufficiently using a ball mill, the sample is placed in a nitrogen-hydrogen mixed gas (97: 3) stream (flow rate: 0.
(1 liter per minute) at 1300 ° C. for 1 hour. Thereafter, the mixture was cooled to room temperature over about 1 hour, the obtained compound powder was sieved and classified, and those that passed 100 mesh were used as phosphor samples 5- (1) to (42).

The XRD of the sample 5- (2) obtained here
The results of the analysis are shown in FIG. As shown in the figure, this phosphor is monoclinic CaAl ₂ O ₄ It was clarified that it consisted of crystals. Next, as a representative example, sample 5- (1) using neodymium, samarium, dysprosium, and thorium as co-activators.
FIGS. 9 and 10 show the results of investigating the thermoluminescence characteristics (glow curves) of (0), 5- (16), 5- (22) and 5- (28). All have a glow peak in a high temperature region of 50 ° C. or higher, suggesting that these phosphors have long afterglow characteristics. Further, when the emission spectrum of the afterglow was measured for the sample, as shown in FIG. 11, the emission peak wavelength of each phosphor was about 44
It emitted blue light of 2 nm.

Therefore, the afterglow characteristics of each of the conventional phosphorescent phosphors of blue light emission, CaSrS: Bi (trade name: BA-S, manufactured by Nemoto Special Chemical Co., Ltd.) of 454 nm, are compared. Tables 8 to 13 show the results of the comparative investigation. Table 8 shows that CaAl ₂ O ₄ : Eu
Regarding the phosphor, when Eu is 0.005 mol (0.5 mol%), the luminance at the initial stage of afterglow is low, but after 100 minutes, the luminance almost equal to the commercial standard product is obtained. Further, as shown in Tables 9 to 13, the addition of the co-activator greatly sensitized the phosphor, and it was possible to obtain a phosphor having sufficiently high practicality using any of the co-activators. In particular, Nd, Sm, and Tm have a remarkable effect on their addition, and it is clear that a superluminous blue light-emitting phosphorescent phosphor that is one order of magnitude brighter than commercial products can be obtained, and can be said to be an epoch-making phosphor. FIG. 12 shows the results of investigating the afterglow characteristics of the high-brightness phosphor obtained by co-activating Nd, Sm and Tm over a long period of time.

In detail, calcium is used as the metal element (M) and europium is used as the activator, but when the co-activator is not used, the phosphorescent phosphor is not used.
Table 8 shows the afterglow characteristics of the phosphorescent phosphors described in (1) to (6).

[0042]

[Table 8]

When calcium is used as the metal element (M), europium is used as the activator, and neodymium is used as the co-activator, the phosphorescent phosphor is 5-
Table 9 shows the afterglow characteristics of the phosphorescent phosphors shown in (7) to (12).

[0044]

[Table 9]

Further, when calcium is used as the metal element (M), europium is used as the activator, and samarium is used as the co-activator, 5- (1)
Table 10 shows the afterglow characteristics of the phosphorescent phosphors shown in 3) to (18).

[0046]

[Table 10]

When calcium is used as the metal element (M), europium is used as the activator, and dysprosium is used as the coactivator, the phosphorescent phosphor is 5
Table 11 shows the afterglow characteristics of the phosphorescent phosphors shown in (19) to (24).
It was shown to.

[0048]

[Table 11]

When calcium is used as the metal element (M), europium is used as an activator, and thulium is used as a co-activator, 5- (25)
Table 12 shows the afterglow characteristics of the phosphorescent phosphors shown in (30) to (30).

[0050]

[Table 12]

Calcium is used as a metal element (M), europium is used as an activator, and lanthanum, cerium, praseodymium, gadolinium, terbium, holmium, erbium, ytterbium, and co-activator are used.
Lutetium, manganese, tin, as a phosphorescent phosphor when using any of the elements of bismuth, 5- (31) ~ (42)
Table 13 summarizes the afterglow characteristics of the phosphorescent phosphors shown in Table 13.

In the phosphorescent phosphors shown in 5- (31) to (42), europium as an activator and other co-activators were both added by 0.5 mol%.

[0053]

[Table 13]

Next, a case where calcium is used as the metal element (M), europium is used as the activator, and neodymium is used as the co-activator, but another co-activator is added at the same time as Example 6 will be described. Embodiment 6 FIG. CaAl ₂ O ₄ : Synthesis of Eu, Nd-based phosphorescent phosphors and their properties Europium oxide (Eu ₂₎ is used as an activator for reagent grade calcium carbonate and alumina. O ₃ ⁾ , to which neodymium is added as a co-activator,
And, as another co-activator, any of lanthanum other than neodymium, cerium, praseodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin, bismuth, respectively For example, 5 g (0.08 mol) of boric acid was added as a flux to the one added with the oxide, and the mixture was sufficiently mixed using a ball mill. Then, the sample was subjected to a stream of nitrogen-hydrogen mixed gas (97: 3) using an electric furnace. Medium (flow rate: 0.1 liter per minute)
At 1300 ° C. for 1 hour. Thereafter, the mixture was cooled to room temperature over about 1 hour, and the obtained compound powder was classified by sieving.
The phosphor sample that passed through 00 mesh was used as the phosphor sample 6- (1) to (4).
3).

Here, first, various phosphor samples were prepared by setting Eu: 0.5 mol%, Nd: 0.5 mol%, and other co-activator: 0.5 mol%. The luminance and the luminance after 100 minutes were measured. The result is 6- (1)
Table 14 shows the results as () to (15).

[0056]

[Table 14]

From the measurement results, it was confirmed that lanthanum, dysprosium, gadolinium, holmium, erbium, and the like among the co-activators added together with neodymium and having particularly excellent afterglow luminance were confirmed. Then, after setting Eu: 0.5 mol% and Nd: 0.5 mol%,
The experiment was performed by changing the concentration of lanthanum from 0.1 mol% to 10 mol%. Table 1 shows the results as 6- (16) to (21).
It is shown in FIG.

[0058]

[Table 15]

The experiment was carried out by changing the concentration of dysprosium from 0.1 mol% to 10 mol% after setting Eu: 0.5 mol% and Nd: 0.5 mol%. The results are expressed as 6- (22)-(2
7) is shown in Table 16.

[0060]

[Table 16]

The experiment was conducted by changing the concentration of gadolinium from 0.1 mol% to 10 mol% after setting Eu: 0.5 mol% and Nd: 0.5 mol%. The results are 6- (28)-(32)
As shown in Table 17.

[0062]

[Table 17]

After setting Eu: 0.5 mol% and Nd: 0.5 mol%, the concentration of holmium was changed from 0.1 mol% to 10 mol%.
The experiment was performed by changing to. The results are shown in Table 18 as 6- (33) to (37).

[0064]

[Table 18]

After Eu: 0.5 mol% and Nd: 0.5 mol%, the concentration of erbium was increased from 0.1 mol% to 5 mol%.
The experiment was performed by changing to. The results are shown in Table 19 as 6- (38) to (43).

[0066]

[Table 19]

From the above measurement results, it was confirmed that when a plurality of coactivators were mixed, the afterglow luminance was improved. Furthermore, in that case, Eu: 0.5 mol%, N
d: 0.5 mol% and other coactivators 0.5 mol%
It was also confirmed that the most excellent afterglow characteristics were exhibited when the addition was made to a certain extent. Next, a phosphorescent phosphor using barium as a metal element (M), europium as an activator, and neodymium or samarium as a coactivator will be described as a seventh embodiment. Embodiment 7 FIG. BaAl ₂ O ₄ : Eu-based phosphor In this case, 0.5 mol% of Eu is added, and Nd or Sm is further added to each of 0.5 mol% to obtain 7- (1)
, (2).

FIG. 13 shows the excitation spectrum and the afterglow emission spectrum of the phosphor of the present invention using neodymium as a co-activator 30 minutes after the stimulation was stopped. FIG. 14 shows the excitation spectrum and the afterglow emission spectrum 30 minutes after the stimulus was stopped, although samarium was used as the co-activator.

The peak wavelength of the emission spectrum is about 500 nm and the emission is green.
Compared with a commercially available ZnS: Cu phosphorescent phosphor (manufactured by Nemoto Special Chemical Co., Ltd .: product name: GSS, emission peak wavelength: 530 nm) which emits green light after stimulus cessation, its afterglow characteristic is 10
The afterglow intensity after minutes, 30 minutes and 100 minutes was shown as a relative value.

[0070]

[Table 20]

From Table 20, it can be seen that BaAl_Two O_Four : Eu,
Nd is 30 times more active than ZnS: Cu phosphorescent phosphor after cessation of stimulation.
It can be seen that the afterglow brightness is excellent for about minutes. Also Ba
Al _Two O_Four : Eu, Sm is ZnS: Cu phosphorescent phosphor
The result was that the afterglow luminance was slightly inferior. However
Without adding Eu or other co-activators, BaAl_Two O _Four
As a result of experiments using only crystals, no fluorescence or afterglow was observed.
Eu and Nd
It is clear that the activation effect can be obtained by adding Sm.
is there.

It should be noted that BaAl ₂ O ₄ : Since the Eu-based phosphor is an oxide-based phosphor, it is chemically more stable than the conventional sulfide-based phosphorescent phosphor and has excellent light resistance (see Tables 24 and 25). Next, a case where a mixture of calcium and strontium was used as the metal element (M) will be described as Example 8. Embodiment 8 FIG. Sr _X Ca _1-X Al ₂ O ₄ Synthesis of phosphorescent phosphors and their properties Reagent grade strontium carbonate and calcium carbonate were mixed at different ratios, alumina was added to the sample, europium was further used as an activator, and lanthanum, cerium, praseodymium was used as a co-activator. 5 g of, for example, boric acid as a flux to a substance to which one of neodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin and bismuth is added
(0.08 mol) and Sr _X Ca
_1-X Al ₂ O ₄ A system phosphor sample was synthesized.

As a representative characteristic of the obtained phosphor, Sr _0.5
Ca _0.5 Al ₂ O ₄ : FIG. 15 shows the result of investigating the afterglow emission spectrum of the Eu and Dy phosphors (added with 0.5 mol% of Eu and 0.5 mol% of Dy). From the figure, when a part of Sr is replaced by Ca, the emission spectrum shifts to the shorter wavelength side, and SrAl ₂ O ₄ Light emission by Ca-based phosphor and CaAl
_Two O ₄ It became clear that afterglow of an intermediate color of light emission of the system phosphor could be obtained.

Next, Sr _x to which 0.5 mol% of Eu and Dy were added as an activator and a co-activator was added. Ca _1-x
Al ₂ O ₄ FIG. 16 shows the result of investigation of the afterglow characteristics of the system phosphor sample. From FIG. 16, it can be seen that a highly practical phosphorescent phosphor having excellent afterglow characteristics equal to or more than that of the commercially available standard product shown by the broken line in any of the phosphors is obtained.

Next, a case where a mixture of strontium and barium is used as the metal element (M) will be described as a ninth embodiment. Embodiment 9 FIG. Sr _X Ba _1-X Al ₂ O ₄ Synthesis of phosphorescent phosphors and their properties Reagent grade strontium carbonate and barium carbonate were mixed at different ratios, alumina was added to the sample, europium was further used as an activator, and lanthanum, cerium, praseodymium was used as a co-activator. 5 g of, for example, boric acid as a flux to a substance to which one of neodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin and bismuth is added
(0.08 mol) and Sr _X Ba _1-X
Al ₂ O ₄ A system phosphor sample was synthesized.

As typical characteristics of the obtained phosphor, S adjusted by adding 0.5 mol% of Eu and 0.5 mol% of Dy was added.
r _X Ba _1-X Al ₂ O ₄ FIG. 17 shows the result of investigating the afterglow characteristics of the system phosphor sample. From FIG. 17, it can be seen that a highly practical phosphorescent phosphor having excellent afterglow characteristics equal to or higher than that of the commercial standard product indicated by the broken line in any of the phosphors can be obtained.

Next, strontium was used as the metal element (M).
In the case of using a mixture of
A description will be given of a tenth embodiment. Embodiment 10 FIG. Sr_X Mg_1-X Al_Two O_Four Phosphorescent phosphor
Of strontium carbonate and magnesium carbonate
Change the ratio of each, mix and add alumina to the sample,
In addition, europium is used as an activator, and
, Cerium, praseodymium, neodymium, summary
, Gadolinium, terbium, dysprosium, e
Lumium, erbium, thulium, ytterbium, le
One of the following elements: Tetium, Manganese, Tin, Bismuth
5g of boric acid, for example, as a flux
(0.08 mol), and Sr was added by the method described above._X Mg_1-X
Al_Two O_Four A system phosphor sample was synthesized. Of the obtained phosphor
0.5 mol% of Eu and 0.5 mol of Dy as representative characteristics
% Adjusted Sr_X Mg_1-X Al_Two O_Four Phosphor
FIG. 18 shows the result of examining the persistence characteristics of the sample.

From FIG. 18, strontium / magnet
Any fluorescence except when 0.1 / 0.9
The body is also compared with the commercial standard product indicated by the broken line in the figure.
Highly practical luminous properties with equal or better afterglow properties
It can be seen that a phosphor is obtained. Next, the metal element (M)
Using multiple metal elements and using Euro as an activator
When using pium and two co-activators,
Thus, a description will be given of an eleventh embodiment. Embodiment 11 FIG. Ca_1-X Sr_X Al_Two O_Four : Eu, Nd,
Synthesis of X fluorescent substance and its properties Reagent grade strontium carbonate and calcium carbonate
The mixture was mixed at different ratios, and alumina was added to the sample.
Furthermore, 0.5 mol% of europium as an activator is co-activated.
0.5 mol% of neodymium as an additive
As active agents, lanthanum, dysprosium, holmium
Adds 0.5 mol% of any of the elements to
For example, 5 g (0.08 mol) of boric acid was added as a
Ca by the method of_1-X Sr_X Al_Two O_Four : Eu, N
d, X-based phosphor samples 11- (1) to (9) were synthesized and the remaining
The light properties were investigated.

First, reagent grade strontium carbonate and calcium carbonate were mixed at different ratios, alumina was added to the sample, and europium 0.1 as an activator was added.
11- (1)-(3) were obtained by adding 5 mol%, 0.5 mol% of neodymium as a co-activator and 0.5 mol% of lanthanum as another co-activator. Shown in

[0080]

[Table 21]

Also, special grades of strontium carbonate and calcium carbonate were prepared at different ratios, alumina was added to the sample, and europium 0.5 was used as an activator.
Mol%, 0.5 mol% of neodymium as a co-activator, and 0.5% dysprosium as another co-activator.
The mol% addition is defined as 11- (4) to (6), and Table 22
Shown in

[0082]

[Table 22]

Further, special grades of strontium carbonate and calcium carbonate were prepared at different ratios, alumina was added to the sample, and europium 0.5 was used as an activator.
11- (7)-(9) were obtained by adding 0.5 mol% of neodymium as a co-activator and 0.5 mol% of holmium as another co-activator. Show.

[0084]

[Table 23]

From these measurement results, the metal element (M)
However, even when a plurality of metal elements (M) composed of calcium and strontium are used, europium is added as an activator, and a plurality of co-activators are added,
It was confirmed that it was superior to CaSrS: Bi, including the luminance after 0 minutes. Embodiment 12 FIG. Table 24 shows the results of examining the moisture resistance properties of the phosphorescent phosphor obtained according to the present invention.

In this investigation, a plurality of phosphor samples were
It was left for 500 hours in a thermo-hygrostat adjusted to 95 ° C. and 95% RH, and the change in luminance before and after that was measured. From the table, it can be seen that the phosphors of any compositions are stable with little effect on humidity.

[0087]

[Table 24]

Embodiment 13 FIG. Light fastness test results Table 25 shows the results of light fastness tests of the phosphorescent phosphors obtained according to the present invention, in comparison with the results of zinc sulfide based phosphors. In this test, the sample was placed in a transparent container adjusted to saturation humidity under a 300 W mercury lamp in accordance with JIS standards.
Irradiation was performed for 3 hours, 6 hours and 12 hours at the position of cm, and the change in luminance after that was measured.

From the table, it can be seen that it is extremely stable as compared with the conventional zinc sulfide-based phosphor.

[0090]

[Table 25]

The phosphorescent phosphor according to the present invention has the following features:
It can be used by applying it to the surface of various products,
It can also be used by mixing it with plastic, rubber or glass. Furthermore, when used in applications such as various instruments, dials of night watches, safety signboards, etc. by replacing conventional sulfide phosphorescent phosphors, their long-lasting high-brightness persistence characteristics , Which is extremely excellent.

The phosphor of the present invention has extremely high luminance and long persistence characteristics, and is chemically stable because it is an oxide and has excellent light resistance. In addition to the applications, the following applications can be newly considered. Vehicle display: airplane, ship, car, bicycle, key or keyhole Sign display: road traffic sign, lane display, display on guardrail, guidance display for fishing buoy, mountain road, guidance display from gate to entrance, helmet Signs Outdoor sign: Signboard, building sign, car keyhole sign Indoor sign: Electric appliance switch Stationery: Writing implement, luminous ink, map, constellation table Toys: Jigsaw puzzle Special use: Sports Ball Backlight for liquid crystal (used in watches, etc.) Replacement of isotopes used in discharge tubes

[0093]

As described above, the present invention relates to a novel phosphorescent phosphor material which is completely different from the conventionally known sulfide phosphors, and relates to a commercially available sulfide phosphor. Compared to this, it has a long-lasting characteristic of high luminance for a much longer time, and is chemically stable because of being an oxide type, and has excellent light resistance.

[Brief description of the drawings]

FIG. 1 SrAl ₂ O ₄ : XR crystal structure of Eu phosphor
6 is a graph showing the results of analysis by D.

FIG. 2 SrAl ₂ O ₄ : A graph showing the excitation spectrum of the Eu phosphor and the emission spectrum 30 minutes after the stimulation was stopped.

FIG. 3 SrAl ₂ O ₄ : The afterglow characteristic of the Eu phosphor is Z
5 is a graph showing the results of comparison with the afterglow characteristics of n: S phosphor.

FIG. 4 SrAl ₂ O ₄ : Is a graph showing the thermoluminescence characteristics of the Eu phosphor.

FIG. 5 SrAl ₂ O ₄ 5 is a graph showing the results of comparing the afterglow characteristics of the: Eu, Dy phosphor with the afterglow characteristics of the Zn: S phosphor.

FIG. 6: SrAl ₂ O ₄ : Is a graph showing the thermoluminescence characteristics of Eu, Dy phosphors.

FIG. 7: SrAl ₂ O ₄ : Is a graph showing the thermoluminescence characteristics of Eu, Nd phosphors.

FIG. 8: CaAl ₂ O ₄ : The crystal structure of the Eu-based phosphor is X
It is the graph which showed the result analyzed by RD.

FIG. 9: CaAl ₂ O ₄ : A graph showing the thermoluminescence characteristics of phosphors using neodymium or samarium as a co-activator among Eu-based phosphors.

FIG. 10: CaAl ₂ O ₄ : Is a graph showing the thermoluminescence characteristics of a phosphor using dysprosium or thorium as a coactivator among Eu-based phosphors.

FIG. 11: CaAl ₂ O ₄ : A graph showing an emission spectrum 5 minutes after the stop of the stimulation of the Eu-based phosphor.

FIG. 12: CaAl ₂ O ₄ : Eu, Sm phosphor and Ca
Al ₂ O ₄ 5 is a graph showing the result of comparing the afterglow characteristics of the: Eu, Nd phosphor with the afterglow characteristics of the Zn: S phosphor.

FIG. 13: BaAl ₂ O ₄ : A graph showing the excitation spectrum of the Eu, Nd phosphor and the emission spectrum 30 minutes after the stimulation was stopped.

FIG. 14: BaAl ₂ O ₄ : A graph showing the excitation spectrum of the Eu and Sm phosphors and the emission spectrum 30 minutes after the stimulation was stopped.

FIG. 15 Sr _0.5 Ca _0.5 Al ₂ O ₄ : Is a graph showing the emission spectrum of the Eu, Dy phosphor.

FIG. 16: Sr _x Ca _1-x Al ₂ O ₄ 5 is a graph comparing the afterglow characteristics of the: Eu, Dy phosphor with the afterglow characteristics of the Zn: S phosphor and the CaSrS: Bi phosphor.

FIG. 17: Sr _x Ba _1-x Al ₂ O ₄ 5 is a graph comparing the afterglow characteristics of the: Eu, Dy phosphor with the afterglow characteristics of the Zn: S phosphor.

FIG. 18 shows Sr _x Mg _1-x Al ₂ O ₄ 5 is a graph comparing the afterglow characteristics of the: Eu, Dy phosphor with the afterglow characteristics of the Zn: S phosphor.

────────────────────────────────────────────────── ───

[Procedure amendment]

[Submission date] February 21, 2001 (2001.2.2)
1)

[Procedure amendment 1]

[Document name to be amended] Statement

[Correction target item name] Full text

[Correction method] Change

[Correction contents]

[Document Name] Statement

[Title of the Invention] Luminescent phosphor

[Claims]

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a phosphorescent phosphor, and more particularly to a novel phosphorescent phosphor having excellent light resistance and having an extremely long afterglow characteristic, which can be used mainly for nighttime display indoors and outdoors. Things.

[0002]

2. Description of the Related Art Generally, the afterglow time of a phosphor is extremely short.
When the external stimulus is stopped, its light emission is attenuated immediately,
In rare cases, after stimulating with ultraviolet rays or the like, after stimulating is stopped, afterglow is observed with the naked eye for a considerably long time (several tens of minutes to several hours), and these are distinguished from ordinary phosphors. It is called a phosphorescent phosphor or phosphor.

The phosphorescent phosphor is CaS: Bi.
(Violet-blue emission), CaSrS: Bi (blue emission), Zn
Sulfide phosphors such as S: Cu (green light emission) and ZnCdS: Cu (yellow to orange light emission) are known, and any of these sulfide phosphors is chemically unstable or light-fast. There are many problems in practical use such as poor performance. Zinc sulfide phosphorescent phosphor (ZnS: C) currently used exclusively in the market
Also, u) is difficult to use in applications where it is exposed to direct sunlight outdoors, especially in the presence of moisture, because it is photodegraded by ultraviolet rays and blackened or its brightness is reduced. Its use, such as indoor night display, has been limited.

Even when this zinc sulfide-based phosphor is used in a luminous timepiece, the afterglow time during which the time can be recognized by the naked eye is about 30 minutes to about 2 hours. At present, it has been necessary to use a self-luminous luminous paint which emits constantly by adding a radioactive substance and stimulating with the energy.

[0005]

In view of the above-mentioned situation, the present inventor has far longer afterglow characteristics than commercially available sulfide-based phosphors, and furthermore, has a chemical An object of the present invention is to provide a phosphorescent phosphor that is stable and has excellent light resistance over a long period of time.

[0006]

As a novel phosphorescent phosphor material completely different from the conventionally known sulfide phosphor, attention has been paid to the alkaline earth metal aluminate activated with europium and the like. As a result of this experiment, this phosphorescent phosphor material has a much longer afterglow characteristic than a commercially available sulfide phosphor, and furthermore, it is chemically oxidized because it is an oxide phosphor. It can be confirmed that it is stable and excellent in light resistance, can solve all the conventional problems, and can be applied to various uses as a luminous paint or pigment that can be seen all night without containing radioactivity. It has become clear that it is possible to provide an afterglow phosphorescent substance.

[0007] The phosphorescent phosphor as described above is a compound represented by MAl ₂ O ₄ .
And M is a compound consisting of a metal element that is strontium.
To a mother crystal and Europium as an activator
0.002% or more and 20% by mol% based on the metal element represented by M
Lanthanum and cerium as co-activators
Mu, praseodymium, neodymium, samarium, gadolinium
, Terbium, dysprosium, holmium, erbium
Um, thulium, ytterbium, lutetium, manga
At least one of the group consisting of tin, tin, and bismuth
0.006% or less in terms of mole percent of the metal element represented by M
10% or less (except for co-activation)
Neodymium, samarium, dysprosium, e
Lumium, erbium, thulium, ytterbium, le
Except those using only one or more of the group consisting of
H). What is claimed in claim 2 is represented by MAl ₂ O ₄
M is a metal element that is strontium
Compound as a mother crystal, and Yu as an activator
0.002 by mol% of the metal element represented by M
% To 20%, and as a co-activator
Jim, gadolinium, terbium, manganese, tin, bi
At least one or more elements of the group consisting of smth are represented by M.
0.006% or more and 10% or less in terms of mole% based on the metal element
It is characterized by having been added. According to claim 3, MA
a compound represented by l ₂ O ₄ , wherein M is calcium
A compound consisting of a metal element into a mother crystal
For metal elements represented by M for europium as an agent
% Or more and not more than 20%, in addition to
Lantern, cerium, praseodymium, neodymium,
Marium, gadolinium, terbium, dysprosium
, Holmium, erbium, thulium, ytterbiu
, Lutetium, manganese, tin, bismuth
At least one element of the metal element represented by M
It is characterized in that it is added in an amount of 0.006% to 10% in terms of mol%
(However, lanthanum, neodymium,
, Samarium, gadolinium, dysprosium, hol
Medium, Erbium, Thulium, Ytterbium, Lute
Using only one or more of the group consisting of
Excluding those using only guns). Claim 4
Is a compound represented by MAl ₂ O ₄ and M is calcium
Consisting of metal elements chromium and strontium
As a mother crystal, and europium as an activator
Not less than 0.002% and not more than 20%
Lanthanum, cerium,
Praseodymium, neodymium, samarium, gadolinium,
Terbium, dysprosium, holmium, erbium
, Thulium, ytterbium, lutetium, manga
At least one of the group consisting of tin, tin, and bismuth
0.006% or less in terms of mole percent of the metal element represented by M
10% or less of the phosphorescent phosphor,
However, as co-activators, neodymium, samarium, disp
Rosium, holmium, erbium, thulium, ytte
Using only one or more of the group consisting of rubium and lutetium
Except for What is described in claim 5 is claim 1,
In addition to the structure described in 2, 3, or 4,
It is characterized by the addition of calcium. Claim 6
Is a compound represented by MAl ₂ O ₄ , where M is
When a compound consisting of a metallic element
In addition, europium is used as an activator as a metal element represented by M.
0.002% or more and 20% or less in terms of mol%, and
Lanthanum, cerium, praseodymium, neo as activators
Jim, Samarium, Gadolinium, Terbium, Disp
Rosium, holmium, erbium, thulium, ytte
From rubium, lutetium, manganese, tin, bismuth
A metal element represented by M for at least one element of the group
0.006% or more and 10% or less in terms of mol%
(However, as co-activators, neodymium,
Marium, dysprosium, holmium, erbium,
One of the group consisting of thulium, ytterbium and lutetium
Except those using only one or more). Claim 7
Is a compound represented by MAl ₂ O ₄ and M is
Compounds consisting of metal elements such as nium and barium
In addition to the mother crystal, europium is used as an activator in M
0.002% or more and 20% or less in terms of mol% based on the metal element
Lanthanum, cerium and platinum as co-activators.
Raceodymium, neodymium, samarium, gadolinium, te
Rubium, dysprosium, holmium, erbium,
Thulium, ytterbium, lutetium, manganese, sulfur
And at least one element of the group consisting of bismuth
0.006% or more and 10% by mol% based on the metal element represented by M
It is characterized by the following addition (however,
, Neodymium, samarium, dysprosium, holmium
, Erbium, thulium, ytterbium, lutechiu
Excluding those using only one or more of the group consisting of

In synthesizing these phosphorescent phosphors, for example, boric acid can be added as a flux in the range of 1 to 10% by weight. Where the addition amount is 1% by weight
If it is less than the above, the flux effect will be lost, and if it exceeds 10% by weight, it will solidify, and subsequent pulverization and classification work will be difficult.

[0009]

EXAMPLES The following description is directed to MAl ₂ O ₄ Examples of the present invention represented by the following formulas will be sequentially described for cases where the type of metal element (M), the concentration of europium as an activator, or the type and concentration of a co-activator are variously changed. First, the present invention will be explained.
For explanation, a phosphorescent phosphor using strontium as a metal element (M) and europium as an activator but not using a coactivator will be described as Reference Example 1. Reference Example 1. SrAl ₂ O ₄ : Synthesis of Eu phosphor and its characteristics Sample 1- (1) Europium oxide (Eu ₂ ) was used as an activator for 146.1 g (0.99 mol) of strontium carbonate and 102 g (1 mol) of alumina. O ₃ ) 1.76 g (0.005
Mol) and further add, for example, boric acid as a flux.
After adding 5 g (0.08 mol) and mixing thoroughly using a ball mill, the sample was placed in a stream of nitrogen-hydrogen mixed gas (97: 3) (flow rate: 0.1 liter / minute) using an electric furnace.
C. for 1 hour. Thereafter, the mixture was cooled to room temperature over about 1 hour, and the obtained compound powder was sieved and classified, and one that passed through 100 mesh was defined as phosphor sample 1- (1).

FIG. 1 shows the result of analyzing the crystal structure of the synthesized phosphor by XRD (X-ray diffraction). The phosphor obtained from the characteristic of the diffraction peak is SrAl ₂ O ₄ In
That it has become apparent. FIG. 2 shows the excitation spectrum of the present phosphor and the emission spectrum of afterglow after the stimulation was stopped.

From the figure, it is clear that the emission spectrum is green emission having a peak wavelength of about 520 nm.
Next, this SrAl ₂ O ₄ : A ZnS: Cu phosphorescent phosphor which emits green light with the afterglow characteristic of a Eu phosphor as a commercial product (manufactured by Nemoto Specialty Chemical Co., Ltd .: product name: GSS, emission peak wavelength: 530)
3 and Table 2 show the results measured in comparison with the afterglow characteristics of (nm).

The measurement of the afterglow characteristic was performed using 0.05 g of phosphor powder.
Is weighed into an aluminum sample dish with an inner diameter of 8 mm (sample thickness:
0.1 g / cm @ 2), after clearing the afterglow Store in about 15 hours dark, then stimulated 10 minutes with the brightness of 200 lux by D ₆₅ standard light source, using a photomultiplier tube subsequent afterglow It was measured by a luminance measuring device. As is clear from FIG. 3 , SrAl ₂ O ₄ : Afterglow of the Eu phosphor is extremely large and its attenuation is slow, and Z
It can be seen that the afterglow intensity difference from the nS: Cu phosphorescent phosphor becomes large. Also in the figure, the level of sufficiently recognizable emission intensity with the naked eye (equivalent to the luminance of about 0.3mCd / m2) indicated by the broken line, this SrAl ₂ O ₄ : It is presumed that the luminescence can be recognized even after about 24 hours from the afterglow characteristic of the Eu phosphor. This Sr 15 hours after the actual stimulation
Al ₂ O ₄ : When the Eu phosphor was observed with the naked eye, the afterglow was sufficiently confirmed.

Sample 1- (1) in Table 2 shows the afterglow intensity at 10 minutes, 30 minutes and 100 minutes after the cessation of stimulation,
S: Relative to the intensity of the Cu phosphorescent phosphor.
From this table it can be seen that SrAl ₂ according to the invention O ₄ : Afterglow luminance of the Eu phosphor after 10 minutes was 2.9 of the ZnS: Cu phosphorescent phosphor.
It can be seen that it is twice and 17 times after 100 minutes. Further, according to the present invention, SrAl ₂ O ₄ : FIG. 4 shows the results of investigating the thermoluminescence characteristics (glow curve) from room temperature to 250 ° C. when light stimulating the Eu phosphor using a TLD reader (KYOKKO TLD-2000 system). From the figure, it can be seen that the thermal emission of this phosphor is composed of three glow peaks of about 40 ° C., 90 ° C., and 130 ° C., and the peak at about 130 ° C. is the main glow peak. ZnS: Cu shown by a broken line in the figure
In view of the fact that the main glow peak of the phosphorescent phosphor is about 40 ° C., the SrAl ₂ O ₄ : It is considered that the deep trap level corresponding to the high temperature of 50 ° C. or higher of the Eu phosphor increases the time constant of afterglow and contributes to the long-term light storage characteristics.

Samples 1- (2) to (7) Next, in the same manner as described above, SrAl ₂ having a compounding ratio shown in Table 1 in which the concentration of europium was changed. O ₄ : Eu phosphor samples (samples 1- (2) to (7)) were prepared.

[0015]

[Table 1]

The results of the examination of the afterglow characteristics of the samples 1- (2) to (7) are shown in Table 2 together with the results of the examination of the afterglow characteristics of the sample 1- (1). From Table 2, it can be seen that the amount of Eu added is
It can be seen that when the content is in the range of 0.005 to 0.1 mol, the afterglow characteristic is superior to that of the ZnS: Cu phosphorescent phosphor including the luminance after 10 minutes. However, the amount of Eu added is 0.00
Even in the case of 002 mol or 0.2 mol, the lapse of 30 minutes or more after the stimulation was stopped
It can also be seen that S: has a higher luminance than the Cu phosphorescent phosphor.

Further, since Eu is expensive, it is not meaningful to make Eu 0.2 mol ( 20 mol%) or more in consideration of economical efficiency and deterioration of afterglow characteristics due to concentration quenching. Become. Conversely, judging from the afterglow characteristics, Eu was 0.00002 mol ( 0.002 mol%).
To 0.0001 mol ( 0.01 mol%)
Although the luminance after 0 minutes is inferior to that of the ZnS: Cu luminous phosphor, the luminance is greater than that of the ZnS: Cu luminous phosphor after 30 minutes or more after the stimulation is stopped. The effect of adding Eu used is clear.

Further, SrAl ₂ O ₄ : Since the Eu phosphor is an oxide-based phosphor, it is chemically more stable than the conventional sulfide-based phosphorescent phosphor and has excellent light resistance (see Tables 24 and 25).

[0019]

[Table 2]

Next, a phosphorescent phosphor using strontium as the metal element (M), europium as an activator, and dysprosium as a coactivator will be described as Reference Example 2. Reference example 2. SrAl ₂ O ₄ : Synthesis of Eu and Dy phosphors and their characteristics Sample 2- (1) Europium oxide (Eu ₂ ) was used as an activator for 144.6 g (0.98 mol) of strontium carbonate and 102 g (1 mol) of alumina. O ₃₎ in 1.76g (0 .005
Mol) and dysprosium oxide (Dy ₂ O ₃₎ at 1.87 g (0.005 mol) was added, further, for example, as boric acid 5 g (0.08 mol) was added flux were mixed thoroughly using a ball mill, the sample using an electric furnace nitrogen - hydrogen mixtures It was baked at 1300 ° C. for 1 hour in a gas (97: 3) stream (flow rate: 0.1 liter per minute). Thereafter, the mixture was cooled to room temperature over about 1 hour, and the obtained compound powder was sieved and classified, and the mixture which passed through 100 mesh was defined as phosphor sample 2- (1).

The afterglow characteristics of this phosphor were investigated in the same manner as described above. The results are shown in FIG. As is clear from FIG. 5 , SrAl ₂ O ₄ : Eu,
The afterglow brightness of the Dy phosphor, especially the brightness at the initial stage of the afterglow, is Z
Since it is extremely high compared to the nS: Cu phosphorescent phosphor and has a large time constant of decay, it can be seen that the phosphor is a revolutionary high-luminance phosphorescent phosphor. The visible afterglow intensity level shown in the figure and this SrAl ₂ O ₄ : Emission can be identified even after about 16 hours from the afterglow characteristics of the Eu and Dy phosphors.

Table 4 shows that 10 minutes, 30 minutes, 100 minutes after stimulation.
The afterglow intensity after minutes is compared to the intensity of the ZnS: Cu phosphorescent phosphor.
The relative values of SrA according to the present invention are shown in the table.
l_Two O_Four : Afterglow luminance of Eu, Dy phosphor is Z after 10 minutes.
nS: 12.5 times of Cu phosphorescent phosphor, and after 100 minutes
It turns out that it is 37 times. Furthermore, SrAl according to the present invention
_Two O_Four : 2 from room temperature when Eu, Dy phosphor was photostimulated
Investigation of thermoluminescence characteristics (glow curve) up to 50 ° C
The results are shown in FIG. From FIGS. 6 and 4, the co-activator
Of main luminescence due to the action of Dy
It can be seen that the working temperature changed from 130 ° C. to 90 ° C.
Large light emission from the trap level corresponding to the temperature of 90 ° C.
But SrAl_Two O_Four : Afterglow compared to Eu phosphor
This is considered to be a cause of high luminance at the initial stage.

Samples 2- (2) to (7) Next, in the same manner as described above, the dysprosium concentration was changed and SrAl ₂ was added at the compounding ratio shown in Table 3. O ₄ : Eu, D
y phosphor samples (samples 2- (2) to (7)) were prepared.

[0024]

[Table 3]

The results of the examination of the afterglow characteristics of the samples 2- (2) to (7) are shown in Table 4 together with the results of the examination of the afterglow characteristics of the sample 2- (1). From Table 4, it can be seen that D as a co-activator
Based on the fact that the addition amount of y is far superior to the ZnS: Cu luminous phosphor, including the luminance after 10 minutes, it is understood that the optimum amount is 0.005 to 0.1 mol. However, even if the amount of Dy added is 0.00002 mol, 30 minutes or more after the stimulation is stopped,
Since the ZnS: Cu phosphor has a higher luminance than the phosphorescent phosphor, E used as an activator and a co-activator is used.
The effect of adding u and Dy is apparent. In addition, since Dy is expensive, it is meaningless to make Dy 0.2 mol ( 20 mol%) or more in consideration of economical efficiency and a decrease in afterglow characteristics due to concentration quenching.

It should be noted that SrAl ₂ O ₄ : Since the Eu and Dy phosphors are oxide-based, they are chemically more stable than the conventional sulfide phosphorescent phosphors and have excellent light resistance (see Tables 24 and 25). .

[0027]

[Table 4]

Next, using a strontium as the metal element (M), using a europium as an activator and further the phosphorescent phosphor in the case of using neodymium as a co-activator will be described as a reference example 3. Reference example 3. SrAl ₂ O ₄ : Eu, Nd synthesis of phosphor and characteristics thereof Sample 3- (1) to (7) in a manner similar to that described above, the table 5 with varying concentrations of neodymium
SrAl _{2 of} the compounding ratio shown by O ₄ : Eu, Nd-based phosphor samples (samples 3- (1) to (7)) were prepared.

[0029]

[Table 5]

The results of investigating the afterglow characteristics of these samples 3- (1) to (7) are shown in Table 6.

[0031]

[Table 6]

From Table 6, it can be seen that when the amount of Nd added as a coactivator is in the range of 0.005 to 0.20 mol, 10
It can be seen that the afterglow characteristic is superior to that of the ZnS: Cu phosphorescent phosphor, including the luminance after minutes. However, the added amount of Nd
Even after 0.00002 mole, 60
After about a minute, the phosphor has a higher luminance than the ZnS: Cu phosphorescent phosphor, so that the effect of adding Eu and Nd used as activators and coactivators is clear. In addition, since Nd is expensive, it is meaningless to set Nd to 0.2 mol ( 20 mol%) or more in consideration of economical efficiency and a decrease in afterglow characteristics due to concentration quenching.

Note that SrAl ₂ O ₄ : Since Eu and Nd phosphors are oxide-based, they are chemically more stable and more excellent in light resistance than conventional sulfide-based phosphorescent phosphors (see Tables 24 and 25). . Further, according to the present invention, SrAl ₂ O ₄ : Thermoluminescence characteristics from room temperature to 250 ° C. when glowing Eu and Nd phosphors (glow curve)
Is shown in FIG. 7 for the results obtained by examining Sample 3- (4). From the figure, it can be seen that the main glow peak temperature of thermal emission of the phosphor to which Nd is added as a co-activator is about 50 ° C.

Next, strontium is used as a metal element (M), europium is used as an activator, and lanthanum, cerium, praseodymium, samarium, gadolinium, terbium, holmium, erbium, thulium, ytterbium, lutetium are used as co-activators. A phosphorescent phosphor using any one of the elements of manganese, tin, and bismuth will be described as Example 1 . this
In the examples, the present invention relates to lanthanum,
Lium, praseodymium, gadolinium, terbium, ma
In this case, gangan, tin, and bismuth were used.

Further, where, for the activator and the co-activator, the example of using the europium and neodymium or dysprosium, each relative to the metal element (M)
Considering that a high afterglow luminance is obtained when about 0.01 mol is added, the Eu concentration of the activator is 1.0 mol%.
( 0.01 mol), concentration of co-activator 1.0 mol% ( 0.
(01 mol). Embodiment 1 FIG . SrAl ₂ O ₄ : Effect of other co-activator on Eu-based phosphor As described above, lanthanum, cerium, praseodymium, samarium, gadolinium, terbium,
Holmium, erbium, thulium, ytterbium,
Table 7 shows the results of investigating the afterglow characteristics of the phosphor samples to which lutetium, manganese, tin, and bismuth were added.

As is clear from Table 7, any of the SrAl ₂ O _{3 was} compared with the afterglow characteristics of the commercially available ZnS: Cu phosphor used as a standard. O ₄ : It can be seen that the Eu-based phosphor sample also has a sufficiently practical level, since the afterglow characteristics are improved after a long time of 30 minutes to 100 minutes or more after the stimulation is stopped. Note that SrAl ₂ O ₄ : Since the Eu-based phosphor is an oxide-based phosphor, it is chemically more stable than the conventional sulfide-based phosphorescent phosphor and has excellent light resistance (see Tables 24 and 25).

[0037]

[Table 7]

Next, calcium is used as the metal element (M) and europium is used as an activator, but a phosphorescent phosphor in the case where no co-activator is used, and calcium is used as a metal element and europium is used as an activator. ,
Lanthanum as a co-activator, cerium, praseodymium, Ne <br/> Oh gym, at least one element of the group consisting of samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium ,, manganese, tin, bismuth Example 2 will be described as a second embodiment. In this embodiment, the present invention
Cerium, praseodymium, terbium,
In this case, manganese, tin, and bismuth are used. Embodiment 2 FIG . CaAl ₂ O ₄ : Synthesis of Eu-based phosphorescent phosphor and its properties Europium oxide (Eu ₂₎ is used as an activator for reagent grade calcium carbonate and alumina. O ₃ ), and lanthanum, as a co-activator,
Cerium, praseodymium, neodymium, samarium, gadolinium, terbium, dysprosium, holmium,
Erbium, thulium, ytterbium, lutetium,
For example, 5 g (0.08 mol) of boric acid was further added as a flux to a material to which one of the elements of manganese, tin, and bismuth was added as an oxide thereof, and the mixture was sufficiently mixed using a ball mill. It was baked at 1300 ° C. for 1 hour in a flow of nitrogen-hydrogen mixed gas (97: 3) (flow rate: 0.1 liter per minute) using an electric furnace. Thereafter, the mixture was cooled to room temperature over about 1 hour, the obtained compound powder was sieved and classified, and those that passed 100 mesh were used as phosphor samples 5- (1) to (42).

The XRD of the sample 5- (2) obtained here
The results of the analysis are shown in FIG. As shown in the figure, this phosphor is monoclinic CaAl ₂ O ₄ It was clarified that it consisted of crystals. Next, neodymium in a co-activator as a typical example, using samarium, dysprosium, the tool helium samples 5- (10),
The results of investigating the thermoluminescence characteristics (glow curves) of 5- (16), 5- (22) and 5- (28) are shown in FIGS.
It was shown to. All have a glow peak in a high temperature region of 50 ° C. or higher, suggesting that these phosphors have long afterglow characteristics. Further, when the afterglow emission spectrum of the sample was measured, as shown in FIG. 11, the emission peak wavelength of each phosphor was about 442 n.
m emission of blue light.

Therefore, the afterglow characteristics of each of the conventional phosphorescent phosphors of blue light emission, CaSrS: Bi (trade name: BA-S, manufactured by Nemoto Special Chemical Co., Ltd.) of 454 nm, are compared. Tables 8 to 13 show the results of the comparative investigation. Table 8 shows that CaAl ₂ O ₄ : Eu
Regarding the phosphor, when Eu is 0.01 mol ( 1.0 mol%), the luminance at the initial stage of afterglow is low, but after 100 minutes, the luminance almost equal to the commercial standard product is obtained. Further, as shown in Tables 9 to 13, the addition of the co-activator greatly sensitized the phosphor, and it was possible to obtain a phosphor having sufficiently high practicality using any of the co-activators. In particular, Nd, Sm, and Tm have a remarkable effect on their addition, and it is clear that a superluminous blue light-emitting phosphorescent phosphor that is one order of magnitude brighter than commercial products can be obtained, and can be said to be an epoch-making phosphor. FIG. 12 shows the results of investigating the afterglow characteristics of the high-brightness phosphor obtained by co-activating Nd, Sm and Tm over a long period of time.

In detail, calcium is used as the metal element (M) and europium is used as the activator, but when the co-activator is not used, the phosphorescent phosphor is not used.
Table 8 shows the afterglow characteristics of the phosphorescent phosphors described in (1) to (6).

[0042]

[Table 8]

[0043] Also using calcium as the metal element (M), using a europium as an activator, as phosphorescent phosphor in the case of using the <br/> neodymium as a co-activator, 5- (7)
Table 9 shows the afterglow characteristics of the phosphorescent phosphors shown in (12) to (12).

[0044]

[Table 9]

Further, when calcium is used as the metal element (M), europium is used as the activator, and samarium is used as the co-activator, 5- (1)
Table 10 shows the afterglow characteristics of the phosphorescent phosphors shown in 3) to (18).

[0046]

[Table 10]

When calcium is used as the metal element (M), europium is used as the activator, and dysprosium is used as the coactivator, the phosphorescent phosphor is 5
Table 11 shows the afterglow characteristics of the phosphorescent phosphors shown in (19) to (24).
It was shown to.

[0048]

[Table 11]

When calcium is used as the metal element (M), europium is used as an activator, and thulium is used as a co-activator, 5- (25)
Table 12 shows the afterglow characteristics of the phosphorescent phosphors shown in (30) to (30).

[0050]

[Table 12]

Calcium is used as a metal element (M), europium is used as an activator, and lanthanum, cerium, praseodymium, gadolinium, terbium, holmium, erbium, ytterbium, and co-activator are used.
Lutetium, manganese, tin, as a phosphorescent phosphor when using any of the elements of bismuth, 5- (31) ~ (42)
Table 13 summarizes the afterglow characteristics of the phosphorescent phosphors shown in Table 13.

In the phosphorescent phosphors shown in 5- (31) to (42), europium as an activator and other co-activators were both added by 1.0 mol%.

[0053]

[Table 13]

[0054] Then using calcium as the metal element (M), using a europium as an activator, but using <br/> neodymium as a co-activator, Example 3 a case of adding at the same time other co-activator It will be described as. In this example,
The invention relates to cerium and platinum as co-activators other than neodymium.
Raceodymium, terbium, manganese, tin, bismuth
This is the case when used. Embodiment 3 FIG . CaAl ₂ O ₄ : Synthesis of Eu, Nd-based phosphorescent phosphors and their properties Europium oxide (Eu ₂₎ is used as an activator for reagent grade calcium carbonate and alumina. O ^₃₎ as added thereto plus neodymium as a co-activator, and, as yet another co-activator, lanthanum other than neodymium, cerium, praseodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium , Thulium, ytterbium, lutetium, manganese, tin, and bismuth are each added in the form of an oxide thereof, and then, for example, 5 g (0.08 mol) of boric acid is added as a flux and thoroughly mixed using a ball mill. The sample was placed in a nitrogen-hydrogen mixed gas (97: 3) stream (flow rate: 0.1 liter per minute) using an electric furnace.
It was fired at 1300 ° C. for 1 hour. Thereafter, the mixture was cooled to room temperature over about 1 hour, and the obtained compound powder was sieved and classified to 100
What passed through the mesh was designated as phosphor samples 6- (1) to (43).

[0055] Here, first of all, Eu: 1.0 mol%, Nd: 1.0 mol%, the other co-activator: 1.0 mol%
For each of the phosphor samples, the luminance after 10 minutes, the luminance after 30 minutes, and the luminance after 100 minutes were measured. The result is
Table 14 shows (1) to (15).

[0056]

[Table 14]

[0057] From this measurement result, in a co-activator to be added together with neodymium afterglow luminance as those particularly excellent, lanthanum, dysprosium, gadolinium, holmium, be an erbium or the like was confirmed. Therefore, next, an experiment was performed by changing the concentration of lanthanum from 0.2 mol% to 20 mol% after setting Eu: 1.0 mol% and Nd: 1.0 mol%. The results are shown in Table 15 as 6- (16) to (21).

[0058]

[Table 15]

Eu: 1.0 mol%, Nd: 1.0 mol%
Then, the experiment was performed by changing the concentration of dysprosium from 0.2 mol% to 20 mol%. The result is
Table 16 shows (22) to (27).

[0060]

[Table 16]

Eu: 1.0 mol%, Nd: 1.0 mol%
Gadolinium concentration from 0.2 mol%
The experiment was performed by changing to 20 mol%. The result is expressed as 6- (2
The results are shown in Table 17 as 8) to (32).

[0062]

[Table 17]

Eu: 1.0 mol%, Nd: 1.0 mol%
And the concentration of holmium is changed from 0.2 mol% to 2 mol%.
The experiment was performed by changing to 0 mol%. The result is 6- (33)
Table 18 shows the results as (37).

[0064]

[Table 18]

Eu: 1.0 mol%, Nd: 1.0 mol%
And the concentration of erbium is increased from 0.2 mol% to 1
The experiment was performed by changing to 0 mol%. The result is 6- (38)
The results are shown in Table 19 as-(43).

[0066]

[Table 19]

From the above measurement results, it was confirmed that when a plurality of coactivators were mixed, the afterglow luminance was improved. Furthermore, in that case, Eu: 1.0 mol%,
Nd: on it was 1.0 mol%, other co-activator 1.0
It was also confirmed that the addition of about mol% exhibited the best afterglow characteristics. Then using barium as the metal element (M), using a europium as an activator and further the phosphorescent phosphor in the case of using a neodymium or samarium as the co-activator will be described as a reference example 4. Reference example 4 . BaAl ₂ O ₄ : Eu-based phosphor Here, after adding 1.0 mol% of Eu, Nd is further added.
Alternatively, 1.0 mol% of Sm was added to each of 7-
These are shown as (1) and (2).

[0068] Of the present phosphors in FIG. 13, but using neodymium as a co-activator, showing an emission spectrum of afterglow after a lapse of 30 minutes after stopping the excitation spectrum and irritation. FIG. 14 shows the excitation spectrum and the afterglow emission spectrum 30 minutes after the stimulus was stopped, although samarium was used as the co-activator.

The peak wavelength of the emission spectrum is about 500 nm and the emission is green.
Compared with a commercially available ZnS: Cu phosphorescent phosphor (manufactured by Nemoto Special Chemical Co., Ltd .: product name: GSS, emission peak wavelength: 530 nm) which emits green light after stimulus cessation, its afterglow characteristic is 10
The afterglow intensity after minutes, 30 minutes and 100 minutes was shown as a relative value.

[0070]

[Table 20]

From Table 20, it can be seen that BaAl_Two O_Four : Eu,
Nd is 30 times more active than ZnS: Cu phosphorescent phosphor after cessation of stimulation.
It can be seen that the afterglow brightness is excellent for about minutes. Also Ba
Al _Two O_Four : Eu, Sm is ZnS: Cu phosphorescent phosphor
The result was that the afterglow luminance was slightly inferior. However
Without adding Eu or other co-activators, BaAl_Two O _Four
As a result of experiments using only crystals, no fluorescence or afterglow was observed.
Eu and Nd
It is clear that the activation effect can be obtained by adding Sm.
is there.

It should be noted that BaAl ₂ O ₄ : Since the Eu-based phosphor is an oxide-based phosphor, it is chemically more stable than the conventional sulfide-based phosphorescent phosphor and has excellent light resistance (see Tables 24 and 25). Next, a case of using a mixture of calcium and strontium as the metal element (M) will be described as a fourth embodiment. Embodiment 4 FIG . Sr _X Ca _1-X Al ₂ O ₄ Synthesis of phosphorescent phosphors and their properties Reagent grade strontium carbonate and calcium carbonate were mixed at different ratios, alumina was added to the sample, europium was further used as an activator, and lanthanum, cerium, praseodymium was used as a co-activator. Neo gym, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin, to which was added to one of the elements bismuth, as a flux for example boric acid 5g
(0.08 mol) and Sr _X Ca
_1-X Al ₂ O ₄ A system phosphor sample was synthesized. In this example
In the present invention, as a co-activator, lanthanum, cerium,
Praseodymium, gadolinium, terbium, manganese,
In this case, tin and bismuth are used.

As a representative characteristic of the obtained phosphor, Sr _0.5
Ca _0.5 Al ₂ O ₄ : Eu, shown Dy phosphor (Eu 1.0 mol%, Dy 1.0 mol% addition) the investigation results of the emission spectrum of afterglow of Figure 15. From the figure, when a part of Sr is replaced by Ca, the emission spectrum shifts to the shorter wavelength side, and SrAl ₂ O ₄ Light emission by Ca-based phosphor and CaAl
_Two O ₄ It became clear that afterglow of an intermediate color of light emission of the system phosphor could be obtained.

Next, Sr _x to which 1.0 mol% of Eu and Dy were added as an activator and a co-activator was added. Ca _1-x
Al ₂ O ₄ FIG. 16 shows the result of investigation of the afterglow characteristics of the system phosphor sample. From FIG. 16, it can be seen that a highly practical phosphorescent phosphor having excellent afterglow characteristics equal to or more than that of the commercially available standard product shown by the broken line in any of the phosphors is obtained.

Next, an example in which a mixture of strontium and barium is used as the metal element (M) will be described.
Explanation is made as 5 . Embodiment 5 FIG . Sr _X Ba _1-X Al ₂ O ₄ Synthesis of phosphorescent phosphors and their properties Reagent grade strontium carbonate and barium carbonate were mixed at different ratios, alumina was added to the sample, europium was further used as an activator, and lanthanum, cerium, praseodymium was used as a co-activator. Neo gym, samarium,
A substance to which gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin or bismuth is added, for example, 5 g of boric acid (0.08
Mol) and add Sr _X Ba _1-X Al ₂
O ₄ A system phosphor sample was synthesized. In this example, the invention
Are lanthanum, cerium, praseodymium as co-activators
, Gadolinium, terbium, manganese, tin, bis
This is the case where a cell is used.

Eu is a typical characteristic of the obtained phosphor.
1.0 mol% was adjusted by the addition Dy 1.0 mol% S
r _X Ba _1-X Al ₂ O ₄ FIG. 17 shows the result of investigating the afterglow characteristics of the system phosphor sample. From FIG. 17, it can be seen that a highly practical phosphorescent phosphor having excellent afterglow characteristics equal to or higher than that of the commercial standard product indicated by the broken line in any of the phosphors can be obtained.

Next, a case where a mixture of strontium and magnesium is used as the metal element (M) will be described as a sixth embodiment. Embodiment 6 FIG . Sr _X Mg _1-X Al ₂ O ₄ Synthesis of phosphorescent phosphors and their properties Reagent grade strontium carbonate and magnesium carbonate were mixed at different ratios, and alumina was added to the sample.
Further europium as an activator, doped lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin, one of the elements bismuth as a co-activator 5 g of boric acid as flux
(0.08 mol) and Sr _X Mg _1-X
Al ₂ O ₄ A system phosphor sample was synthesized. The resulting 1.0 mol% of Eu as the representative characteristics of the phosphor, Sr _X adjusted by the addition of Dy 1.0 mol% Mg _1-X Al ₂ O ₄ FIG. 18 shows the result of investigating the afterglow characteristics of the system phosphor sample. this
In the examples, the present invention relates to lanthanum,
Lium, praseodymium, gadolinium, terbium, ma
In this case, gangan, tin, and bismuth were used.

From FIG. 18, except that the strontium / magnesium ratio was 0.1 / 0.9, all the phosphors were equal to or better than the commercial standard products indicated by the broken line in the figure. It can be seen that a highly practical phosphorescent phosphor having afterglow characteristics can be obtained. Next, a case in which a plurality of metal elements are used as the metal element (M), europium is used as the activator, and two co-activators are used will be described as Example 7 . Embodiment 7 FIG . Ca _1-X Sr _X Al ₂ O ₄ : Eu, Nd, X
Neodymium 1 Synthesis of phosphor and characteristics special grade of strontium carbonate and calcium carbonate ratio of alumina to the sample preparation by changing the added respectively, the further europium 1.0 mol% as an activator, as a co-activator. 0 mol%, and 1.0 g% of any of lanthanum, dysprosium and holmium elements as other co-activators, and 5 g (0.08 mol) of boric acid as a flux, for example, are added. Ca _1-X by the method of Sr _X Al ₂ O ₄ : Eu, Nd,
X-based phosphor samples 11- (1) to (9) were synthesized and their afterglow characteristics were investigated. In this example, the present invention relates to other co-activation
In this case, lanthanum was used as the agent.

First, reagent grade strontium carbonate and calcium carbonate were prepared in different ratios, alumina was added to the sample, and europium 1.10 was added as an activator .
0 mol%, neodymium 1.0 mole% was added, as a yet another co-activator as a co-activator, lanthanum 1.0 mol%
The additions are shown in Table 21 as 11- (1) to (3).

[0080]

[Table 21]

In addition, reagent grade strontium carbonate and calcium carbonate were prepared at different ratios, alumina was added to the sample, and europium 1.0 as an activator.
The mole%, neodymium 1.0 mol% was added as a co-activator, as yet another co-activator, dysprosium 1.0
The mol% addition is defined as 11- (4) to (6), and Table 22
Shown in

[0082]

[Table 22]

Also, special grades of strontium carbonate and calcium carbonate were prepared at different ratios, alumina was added to the sample, and europium 1.0 as an activator.
The mole%, neodymium 1.0 mol% was added as a co-activator, as yet another co-activator, a material obtained by adding holmium 1.0 mol% 11- (7) to (9), Table 23 Shown in

[0084]

[Table 23]

From these measurement results, the metal element (M)
However, even when a plurality of metal elements (M) composed of calcium and strontium are used, europium is added as an activator, and a plurality of co-activators are added,
It was confirmed that it was superior to CaSrS: Bi, including the luminance after 0 minutes. Embodiment 8 FIG . The results of the examination of moisture resistance characteristics of the humidity resistance test 蓄 light phosphor are shown in Table 24.

In this investigation, a plurality of phosphor samples were
It was left for 500 hours in a thermo-hygrostat adjusted to 95 ° C. and 95% RH, and the change in luminance before and after that was measured. From the table, it can be seen that the phosphors of any compositions are stable with little effect on humidity.

[0087]

[Table 24]

Embodiment 9 FIG. The result of performing the light resistance test light resistance test results 蓄 light phosphor as compared to the results of the zinc sulfide based phosphor is shown in Table 25. This exam is
According to the JIS standard, the sample was placed in a transparent container conditioned to saturation humidity and placed under a 300 W mercury lamp at a position of 30 cm under a mercury lamp for 3 hours.
Light irradiation was performed for 6 hours and 12 hours, and a change in luminance after that was measured.

From the table, it can be seen that it is extremely stable as compared with the conventional zinc sulfide-based phosphor.

[0090]

[Table 25]

The phosphorescent phosphor according to the present invention has the following features:
It can be used by applying it to the surface of various products,
It can also be used by mixing it with plastic, rubber or glass. Furthermore, when used in applications such as various instruments, dials of night watches, safety signboards, etc. by replacing conventional sulfide phosphorescent phosphors, their long-lasting high-brightness persistence characteristics , Which is extremely excellent.

The phosphor of the present invention has extremely high luminance and long persistence characteristics, and is chemically stable because it is an oxide and has excellent light resistance. In addition to the applications, the following applications can be newly considered. Vehicle display: airplane, ship, car, bicycle, key or keyhole Sign display: road traffic sign, lane display, display on guardrail, guidance display for fishing buoy, mountain road, guidance display from gate to entrance, helmet Signs Outdoor sign: Signboard, building sign, car keyhole sign Indoor sign: Electric appliance switch Stationery: Writing implement, luminous ink, map, constellation table Toys: Jigsaw puzzle Special use: Sports Ball Backlight for liquid crystal (used in watches, etc.) Replacement of isotopes used in discharge tubes

[0093]

As described above, the present invention relates to a novel phosphorescent phosphor material which is completely different from the conventionally known sulfide phosphors, and relates to a commercially available sulfide phosphor. Compared to this, it has a long-lasting characteristic of high luminance for a much longer time, and is chemically stable because of being an oxide type, and has excellent light resistance.

[Brief description of the drawings]

FIG. 1 SrAl ₂ O ₄ : XR crystal structure of Eu phosphor
6 is a graph showing the results of analysis by D.

FIG. 2 SrAl ₂ O ₄ : A graph showing the excitation spectrum of the Eu phosphor and the emission spectrum 30 minutes after the stimulation was stopped.

FIG. 3 SrAl ₂ O ₄ : The afterglow characteristic of the Eu phosphor is Z
5 is a graph showing the results of comparison with the afterglow characteristics of n: S phosphor.

FIG. 4 SrAl ₂ O ₄ : Is a graph showing the thermoluminescence characteristics of the Eu phosphor.

FIG. 5 SrAl ₂ O ₄ 5 is a graph showing the results of comparing the afterglow characteristics of the: Eu, Dy phosphor with the afterglow characteristics of the Zn: S phosphor.

FIG. 6: SrAl ₂ O ₄ : Is a graph showing the thermoluminescence characteristics of Eu, Dy phosphors.

FIG. 7: SrAl ₂ O ₄ : Is a graph showing the thermoluminescence characteristics of Eu, Nd phosphors.

FIG. 8: CaAl ₂ O ₄ : The crystal structure of the Eu-based phosphor is X
It is the graph which showed the result analyzed by RD.

FIG. 9: CaAl ₂ O ₄ : A graph showing the thermoluminescence characteristics of phosphors using neodymium or samarium as a co-activator among Eu-based phosphors.

FIG. 10: CaAl ₂ O ₄ : Is a graph showing the heat emission characteristics of the phosphor used dysprosium or tool helium as among co activators Eu phosphor.

FIG. 11: CaAl ₂ O ₄ : A graph showing an emission spectrum 5 minutes after the stop of the stimulation of the Eu-based phosphor.

FIG. 12: CaAl ₂ O ₄ : Eu, Sm phosphor and Ca
Al ₂ O ₄ 5 is a graph showing the result of comparing the afterglow characteristics of the: Eu, Nd phosphor with the afterglow characteristics of the Zn: S phosphor.

FIG. 13: BaAl ₂ O ₄ : A graph showing the excitation spectrum of the Eu, Nd phosphor and the emission spectrum 30 minutes after the stimulation was stopped.

FIG. 14: BaAl ₂ O ₄ : A graph showing the excitation spectrum of the Eu and Sm phosphors and the emission spectrum 30 minutes after the stimulation was stopped.

FIG. 15 Sr _0.5 Ca _0.5 Al ₂ O ₄ : Is a graph showing the emission spectrum of the Eu, Dy phosphor.

FIG. 16: Sr _x Ca _1-x Al ₂ O ₄ 5 is a graph comparing the afterglow characteristics of the: Eu, Dy phosphor with the afterglow characteristics of the Zn: S phosphor and the CaSrS: Bi phosphor.

FIG. 17: Sr _x Ba _1-x Al ₂ O ₄ 5 is a graph comparing the afterglow characteristics of the: Eu, Dy phosphor with the afterglow characteristics of the Zn: S phosphor.

FIG. 18 shows Sr _x Mg _1-x Al ₂ O ₄ 5 is a graph comparing the afterglow characteristics of the: Eu, Dy phosphor with the afterglow characteristics of the Zn: S phosphor.

 ────────────────────────────────────────────────── ─── Continuing on the front page (72) Inventor Yasumitsu Aoki 1-1-15, Kamiogi, Suginami-ku, Tokyo Maruzo Building Inside Nemoto Special Chemical Co., Ltd. (72) Inventor Takashi Matsuzawa 1-15-1, Kamiogi, Suginami-ku, Tokyo Maruzo Building Nemoto Special Chemical Co., Ltd.

Claims (1)

[Claims] 1. MAl ₂ O ₄ A compound represented by
Is a method in which a compound comprising at least one metal element selected from the group consisting of calcium, strontium and barium is used as a mother crystal, europium is used as an activator, and 0.001% or more by mol% based on the metal element represented by M.
10% or less, and manganese, tin,
At least one element of the group consisting of bismuth
A phosphorescent phosphor which is added in an amount of 0.001% or more and 10% or less in terms of mol% based on a metal element represented by.