JP3311254B2 - Inorganic artificial ceramic granular product having luminous fluorescent properties and method for producing the same - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an inorganic artificial ceramic having a luminous fluorescent property and a method for producing the same, and in particular, has excellent mechanical strength, abrasion resistance and water resistance while having excellent luminous properties and clear luminescent properties. Inorganic artificial ceramics having a luminous fluorescent property that also has properties or weather resistance,
It relates to a method for producing it advantageously.

[0002]

2. Description of the Related Art Conventionally, a phosphorescent phosphor, that is, not only emits light (fluorescence) only when light is irradiated from a light source but also emits afterglow (phosphorescence) even after the irradiation of light is stopped. Phosphors having properties are known, and such luminous phosphors use their luminous characteristics to improve visibility at night, and improve visibility in dark places such as inside buildings. It is used for applications. Specifically, for example, by using a phosphorescent phosphor as a gaze guide or a retroreflector, etc., to improve the visibility of a driver of a vehicle running at night, or in a house or on a ship. By using a phosphorescent phosphor for marking a passage or an emergency exit in a building, visibility in a dark place can be significantly improved.

[0003] As one of such phosphorescent phosphors, aluminate phosphors of alkaline earth metals are known. However, since they are mainly composed of alumina, they are refractory. It is an excellent phosphorescent phosphor having high afterglow and having an extremely long afterglow characteristic. However, such a phosphorescent phosphor is a kind of alumina cement obtained by calcining alumina with an alkaline earth metal such as magnesium, calcium, strontium, or barium, and thus has a strong hydration property. , As it is easily decomposed as it is and has poor durability such as poor light resistance,
In general, it is used in a form mixed with paints, etc.
Recently, it is also used in a form mixed with a resin such as a methyl methacrylate resin having high light transmittance. However, paints and resins are not sufficiently durable such as light resistance, weather resistance and abrasion resistance. Therefore, even if the phosphorescent phosphor is used by being blended into the paint or resin, etc. Therefore, it has been difficult to apply it to applications requiring durability, such as application to floor surfaces.

[0004] As described above, conventionally, when a phosphorescent phosphor is used, it is generally used by mixing it with a paint, a resin, or the like. Therefore, light resistance, weather resistance, and abrasion resistance are used. However, there is a problem that the durability is still insufficient.

[0005]

The present invention has been made in view of such circumstances, and has as its object to have excellent light storage properties and clear light emission characteristics,
In providing artificial ceramics having both excellent mechanical strength, abrasion resistance, water resistance or weather resistance,
Another object of the present invention is to provide a method for advantageously producing an artificial ceramic having such luminous fluorescent characteristics.

[0006]

The present inventors have conducted intensive studies to solve such technical problems, and as a result, have found that SiO ₂ , B ₂
A borosilicate glass containing O ₃ and an alkali metal oxide as main components is used as a base material, and a phosphorescent phosphor made of a predetermined alkaline earth metal aluminate is dispersed and contained in the base material at a predetermined ratio. The present inventors have found that ceramics have excellent light storage properties and luminous properties and also have excellent durability such as weather resistance and abrasion resistance, and have completed the present invention.

That is, the present invention relates to SiO ₂ , B
_In a borosilicate glass base material containing ₂ O ₃ and an alkali metal oxide as main components, a general formula: MO-nAl ₂ O ₃ (where,
M is one kind of metal selected from the group consisting of magnesium, calcium, strontium, and barium or 2
A phosphorescent phosphor comprising at least one metal aluminate salt represented by at least one complex metal) is uniformly dispersed and contained in a content of 3 to 50% by weight. An inorganic artificial ceramic having luminescent properties is the gist of the invention.

As described above, in the inorganic artificial ceramics having luminous fluorescent characteristics according to the present invention, borosilicate glass mainly composed of SiO ₂ , B ₂ O ₃ , and alkali metal oxide is used as a base material. And a general formula: MO-nAl ₂ O ₃ (where M is one metal selected from the group consisting of magnesium, calcium, strontium, and barium, or two or more composite metals) ), The phosphorescent phosphor composed of at least one metal aluminate represented by the formula (1) is dispersed and contained, so that the phosphorescent phosphor that is easily oxidized and decomposed as it is is advantageously produced by the borosilicate glass base material. Thus, the light emission luminance can be effectively reduced. Moreover, such a borosilicate glass base material has a high transmissive property without obstructing the transmission of visible light and ultraviolet light, so that the luminescent phosphor dispersed and contained therein emits light. The properties can be demonstrated effectively.

According to one preferred embodiment of the inorganic artificial ceramics having luminous fluorescent properties according to the present invention, the luminous phosphor contains an activator or a co-activator together with an activator. Is done.

According to another preferred embodiment of the inorganic artificial ceramics having luminous fluorescent properties according to the present invention, the borosilicate glass base material has a melting point of 1000 ° C. or less.

According to still another preferred embodiment of the inorganic artificial ceramics having luminous fluorescent characteristics according to the present invention, the total content of alkaline earth metal oxides in the borosilicate glass base material is 10% by weight. % Or less, and the total content of transition metal oxides is 1.0% by weight or less. And, by defining the total content of the alkaline earth metal oxide and the total content of the transition metal oxide as described above, the emission color of the obtained inorganic artificial ceramics having the phosphorescent fluorescent property according to the present invention can be obtained. A decrease in emission characteristics such as emission luminance can be effectively suppressed, and excellent emission characteristics can be advantageously exhibited.

Further, the present invention relates to a borosilicate glass base material containing SiO ₂ , B ₂ O ₃ , and an alkali metal oxide as main components, and a general formula: MO-nAl ₂ O ₃ (where M
Represents a metal selected from the group consisting of magnesium, calcium, strontium, and barium or two or more composite metals). The phosphor is calcined in an inert atmosphere or a weakly reducing atmosphere at a temperature of 750 ° C. to 900 ° C. so that the phosphorescent phosphor is uniformly dispersed and contained in the borosilicate glass base material. The present invention also provides a method for producing an inorganic artificial ceramic having luminous fluorescent characteristics, characterized in that a sintered body obtained is obtained.

As described above, in the method for producing an inorganic artificial ceramic having luminous fluorescent characteristics according to the present invention, a borosilicate glass base material is employed as a base material. Since the base material can be melt-fired at a low temperature, firing performed to obtain the inorganic artificial ceramic is performed by 75%.
It can be carried out under low temperature conditions, such as 0 ° C. to 900 ° C., so that oxidation and thermal decomposition of the phosphorescent phosphor during firing are effectively suppressed.
Moreover, since the baking treatment is performed in an inert atmosphere or a weakly reducing atmosphere, the oxidation of the phosphorescent phosphor is more effectively suppressed. Therefore, the method of the present invention is characterized in that inorganic artificial ceramics having excellent luminous properties and clear luminescent properties can be advantageously produced.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The inorganic artificial ceramics having luminous fluorescent properties according to the present invention are as follows.
Using a predetermined borosilicate glass as the base material,
A mixture of a phosphorescent phosphor composed of a predetermined alkaline earth metal aluminate, which is obtained by melting and calcining, of which a predetermined alkaline earth metal aluminate is formed the phosphorescent phosphor of the general formula: MO-nAl ₂ O ₃ (where, M represents magnesium, calcium, strontium, and the one metal or two or more composite metal selected from the group consisting of barium) A phosphorescent phosphor composed of at least one of the metal aluminates represented by the following formulas is employed. Specific examples of such phosphorescent phosphors include BaMg ₂ Al ₁₆ O ₂₇ and Sr ₄ Al
₁₄ O _{25 and the} like. Here, n in the above general formula indicates the molar ratio of alkaline earth metal oxide (MO) to alumina (Al ₂ O ₃ ). The phosphorescent phosphor used in the present invention is obtained by firing at a high temperature of about 1300 ° C., and is very stable at a high temperature. Like artificial ceramics, it is suitable as a raw material for those obtained by firing at high temperatures.

If necessary, the phosphorescent phosphor may be added with a predetermined activator or a coactivator together with such an activator, without any problem. In the phosphorescent phosphor to which the agent and the co-activator are added, the emission characteristics such as emission luminance and emission wavelength, the stability at high temperature, and the light resistance are improved. In addition,
As such activators, specifically, europium,
Europium-manganese and the like can be mentioned, and the amount of addition is generally 0.001 mol% to 1 mol% with respect to the alkaline earth metal element which is a constituent element of the phosphorescent fluorescent component.
It is about 0 mol%. The co-activator is selected from the group consisting of lanthanoid elements such as lanthanum, cerium, praseodymium, neodymium, samarium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, manganese, tin, and bismuth. At least one or more elements can be exemplified, and the amount of addition is generally about 0.001 mol% to 10 mol% with respect to the alkaline earth metal element which is a constituent element of the phosphorescent fluorescent component. It is said.

On the other hand, the borosilicate glass used as the base material in the present invention constitutes a main component of the obtained inorganic artificial ceramics having luminous fluorescent properties,
It has an effect of protecting the phosphorescent phosphor,
Such borosilicate glass base materials include SiO ₂ , B ₂
Those containing O ₃ and an alkali metal oxide as main components are used. Here, SiO ₂ is added as a refractory component that imparts fire resistance to the borosilicate glass base material, and forms a basic skeleton of the borosilicate glass base material. On the other hand, B ₂ O ₃ and the alkali metal oxide are added as a low-flammable component having a function of lowering the melting point of the borosilicate glass base material. As the SiO ₂ , silica stone, silica sand, or the like can be used, and even if a small amount of alumina is added thereto, there is no problem.
Further, boric acid and borax can be used as the B ₂ O ₃ , and lithium carbonate, soda ash, chilli saltpeter, saltpeter and the like are used as alkali metal oxides such as Li ₂ O, Na ₂ O, and K ₂ O. , Potassium carbonate and feldspar group can be used. Further, the borosilicate glass base material contains C as a low-flammable component.
alkaline earth metal oxides such as aO, MgO, SrO and Z
lime, magnesium carbonate, magnesia, strontium carbonate and the like can be used as such an alkaline earth metal oxide.
For example, zinc white can be used. The raw material of the borosilicate glass base material is not limited to those exemplified above, and various raw materials can be used.
Of course. Then, after the various raw materials are pulverized and mixed, they are melted to obtain uniform glassy ceramics or frit-like ceramics.

The melting point of the borosilicate glass base material containing various components as described above is approximately 100.
The temperature is set to 0 ° C or lower, preferably 900 ° C or lower. It ’s
The phosphorescent phosphor used in the present invention is usually 1300 ° C.
Although it is fired at about high temperature, when manufacturing inorganic artificial ceramics, before reaching the firing temperature, the borosilicate glass base material is melted and a protective layer surrounding the phosphorescent phosphor is formed. Because it should.

The borosilicate glass base material may be made of heavy metal oxides such as lead oxide (PbO), Fe, Cr, Ni,
When a transition metal such as Co or Cu is contained, the effect of the activator or co-activator contained in the phosphorescent phosphor is adversely affected, and as a result, the fluorescent properties of the phosphor are reduced. It is important that even if it is contained as an impurity, it should be minimized, because it lowers the color and causes discoloration. More specifically, for example, in transition metals such as Fe, Cr, Ni, Co, and Cu, the total content is desirably 1.0% by weight or less.

Further, the borosilicate glass base material has a phosphorescent
High so as not to interfere with the emission characteristics of the fluorescent
Borosilicate glass mother
Preferably, the material is at least translucent. on the other hand,
TiO_Two, ZrO_Two, SnO _TwoMilky materials such as
The higher the weight, the higher the light transmission of the resulting borosilicate glass matrix.
5% by weight or less at most to reduce excessive
It is desirable to be controlled so that
When a large amount of added alumina enters,
Luminescent properties of the resulting inorganic artificial ceramics
Less than 10% by weight
Is preferred.

The borosilicate glass base material as described above is
After adjusting the particle size by using appropriate means such as pulverization, the mixture is mixed with a phosphorescent phosphor pulverized to an appropriate particle size such that the emission characteristics are also good, and the resulting mixture is left as it is.
Alternatively, after being granulated and formed, it is fired at a temperature around the melting point of the borosilicate glass base material, whereby an inorganic artificial ceramic having luminous fluorescent characteristics can be obtained.

The content of the phosphorescent phosphor in the obtained inorganic artificial ceramics having phosphorescent phosphorescent properties imparts high emission luminance, mechanical properties, durability and chemical resistance to the target inorganic artificial ceramics. In order to
It should be 50% by weight, preferably 5-35% by weight. When the content of the phosphorescent phosphor is less than 3% by weight, the desired emission luminance cannot be obtained,
When the content of the luminous phosphor is more than 50% by weight, the luminous luminance reaches saturation and the luminous luminance does not increase any more, which is uneconomical. Since the absolute amount of the borosilicate glass base material that forms the protective layer by enclosing the body is insufficient, water, light, or external environmental factors such as oxygen cause the phosphorescent phosphor to be easily oxidized, decomposed, and hydrolyzed, As a result, the light emission luminance and the durability are easily reduced.

The firing temperature is generally set at 750 to 550, since a protective layer made of a borosilicate glass base material should be formed on the phosphorescent phosphor before the phosphorescent phosphor is decomposed.
The temperature is desirably in the range of 900 ° C., and at a temperature in such a range, the light emission is appropriately managed so as to have appropriate emission luminance.

Further, the atmosphere at the time of firing can be appropriately selected so as not to impair the light emission characteristics of the obtained inorganic artificial ceramics. For example, a protective layer made of a borosilicate glass base material is successfully formed on the phosphor. In such a case, firing in a normal atmosphere in which oxygen is present, for example, in the air, may be performed without any problem.However, the density of the obtained inorganic artificial ceramics having luminous fluorescent properties is increased to reduce the emission luminance. In order to prevent this, it is desirable that the sintering be performed in an inert atmosphere such as nitrogen or argon or a weakly reducing atmosphere containing a small amount of hydrogen.

When obtaining the inorganic artificial ceramics having luminous fluorescent properties according to the present invention, a mixture of a luminous phosphor and a borosilicate glass base material is granulated to a given particle size. It is desirable to adopt a method of firing, or a method of melting the obtained mixture, discharging and cutting it through an orifice or the like, granulating to a given particle size, and then molding. Since the surface of the obtained inorganic artificial ceramics having luminous fluorescent properties is coated with a borosilicate glass base material, the phosphor contained therein is isolated from the outside, whereby hydrolysis, This is because oxidative decomposition is hardly caused, the durability can be greatly improved, and the decrease in the luminance of fluorescence or phosphorescence is reduced.

On the other hand, after mixing the phosphorescent phosphor and the borosilicate glass base material, melting, firing, and cooling the cooled mass or large chip is crushed and sieved to obtain an inorganic artificial ceramic having a given particle size. In the method, since the phosphorescent phosphor is exposed at the fracture surface at the time of pulverization, hydrolysis and oxidative decomposition are more likely to occur as the phosphorescent phosphor content increases. In particular, as the particle size becomes smaller, the specific surface area increases, so that this tendency becomes remarkable. The (crystal) particle size of the phosphorescent phosphor is about 5 to 20 μm,
If the particle size is smaller than that, the phosphorescent brightness is extremely reduced.

Therefore, it is desirable that fine powder particles having an excessively small particle size be removed by sieving or the like, since the emission luminance is reduced. More specifically, the obtained granules of inorganic artificial ceramics having luminous fluorescent properties are:
The emission luminance is reduced to about 1/5 for fine particles less than 5 mm, and the emission luminance is reduced to 1/5 for fine particles less than 0.5 mm.
From the drop to about 15, such ceramics are fine powder particles of less than 0.5 mm, preferably 1.5 m
It is desirable that fine particles of less than m be removed.

The inorganic artificial ceramics having luminous fluorescent properties thus obtained can be advantageously used for various applications in the same manner as conventional ceramics. For example, used as artificial aggregates such as road aggregates, construction aggregates, or ship aggregates,
After pulverization, the sieved product is beaded in a high-temperature vortex such as a gas jet, and used as paint beads or retroreflector beads. It can be used.
In addition, the inorganic artificial ceramics according to the present invention can be used as glazes such as general ceramic glazes and glazes for sign tiles, and enamels for art enamels and sign enamels. Specifically, a layer of the inorganic artificial ceramics is formed on the ceramic or metal surface by applying a crushed product of the inorganic artificial ceramics or a raw material giving the inorganic artificial ceramics to the ceramic surface or the metal surface, and then firing. That's it.
Furthermore, the inorganic artificial ceramics according to the present invention can be used as a thermal spray material for gas type thermal spraying, and can be directly applied to the surface of road-related, building-related, or ship-related equipment.

[0028]

EXAMPLES In order to clarify the present invention more specifically, some examples of the present invention will be shown below.
It goes without saying that the present invention is not subject to any restrictions by the description of such embodiments. In addition, in addition to the following examples, the present invention, in addition to the above-described specific description, various changes, corrections, and modifications based on the knowledge of those skilled in the art without departing from the spirit of the present invention. It should be understood that improvements can be made.

Example 1 First, a raw material having the composition shown in Table 1 below was prepared, melted, and then solidified by cooling and solidifying, and then pulverized to obtain a borosilicate glass base material: A to A F was produced.
The hue of each borosilicate glass base material thus obtained is shown in Table 1 below. The composition shown in Table 1 is a composition after melting. Further, the borosilicate glass base material contains a transition metal such as iron, cobalt, and nickel, or a heavy metal oxide such as PbO, which lowers the emission luminance of the phosphorescent phosphor or changes the emission color. It was made to contain only 1% by weight or less.

[0030]

[Table 1]

On the other hand, strontium aluminate (SrAl ₂ O ₄ ) having a long-term afterglow characteristic is used as the phosphorescent phosphor.
On the other hand, a phosphor prepared by mixing europium (Eu) as an activator and having an appropriate particle size so as not to impair the emission characteristics was prepared. More specifically, first, a reagent-grade strontium carbonate: 0.94 mol and alumina: 1 mol are prepared. On the other hand, europium oxide: 0.005 mol as an activator and dysprosium as a co-activator: A mixture obtained by adding 0.025 mol and further adding 0.05 mol of boric acid as a flux was sufficiently mixed using a ball mill. Then, the obtained mixture is baked for 1 hour under a temperature condition of 1300 ° C. for 1 hour in a weakly reducing air current electric furnace made of a mixed gas of nitrogen and hydrogen, and then cooled to room temperature for 1 hour to obtain a baked product. Obtained. Next, the obtained fired product is pulverized and classified,
What passed through a 100-mesh sieve was used as the phosphorescent phosphor used in this example. Note that the phosphorescent phosphor obtained here exhibits extremely excellent light-emitting properties, and is a phosphorescent phosphorescent phosphor that has been conventionally used, using zinc sulfide as a base material and copper as an activator. The phosphorescent luminance was 20 to 30 times that of the phosphor.

Next, with respect to 70% by weight of each of the borosilicate glass base materials obtained above, 30% by weight of the phosphorescent phosphor was used.
Are mixed at a temperature of 820 ° C.
After baking for 0 minutes, the mixture was allowed to cool in a baking furnace to obtain inorganic artificial ceramics having various phosphorescent fluorescent properties (hereinafter simply referred to as inorganic artificial ceramics). The hues, physical properties, and phosphorescent luminance characteristics before and after the weathering process were examined. The results are shown in Table 2 below.

[0033]

[Table 2]

In Table 2, the physical properties represented by water absorption (%), apparent specific gravity (g / cm ₃ ), bulk specific gravity (g / cm ₃ ), and apparent porosity (%) are as defined in JIS. -A111
0 was measured. As for the phosphorescent brightness,
After irradiating a light source for 4 minutes from a measuring light source installed in a vertical direction with respect to the horizontal plane of the sample (inorganic artificial ceramics), the phosphorescence luminance immediately after the end of the irradiation and the phosphorescence luminance 2 minutes after the end of the irradiation are measured. (See FIG. 1). In addition,
Irradiation conditions include: light source used: halogen lamp, illuminance:
1000 lux, irradiation time: 4 minutes were adopted. Also,
The weathering treatment was performed in accordance with “Accelerated exposure test method WV type” described in JIS-A1415, and the treatment time was 500 hours.

As is clear from the results shown in Table 2, the characteristics of each inorganic artificial ceramic fluctuate greatly depending on the material characteristics of the base material used. In particular, those in which B ₂ O ₃ is about 20 to 30% by weight and the total amount of alkali metal oxides is about 10 to 20% by weight are preferable because the melting point is around 800 ° C. .

The divalent alkaline earth metal oxide is
Although preferred as a low-flammable raw material, In No. 3, the borosilicate glass base material used therein: C in C
Since the content of aO is too large at 12.12% by weight,
The phosphorescent brightness of the obtained inorganic artificial ceramics was reduced to about half, and the emission color changed from green yellow to orange. Therefore, the total content of the alkaline earth metal oxide in the borosilicate glass base material is preferably set to 10.0% by weight or less.

Further, as in a borosilicate glass base material: D,
The borosilicate glass base material containing a large amount of opalescent materials such as titania (TiO ₂ ), zirconia (ZrO ₂ ), tin oxide (SnO ₂ ) becomes white and opaque, and as a result, the inorganic artificial ceramics of Example 4 of the present invention As described above, the light emission performance (phosphorescence luminance) is extremely reduced. Therefore, it is desirable that the content of opacifying materials such as titania, zirconia, and tin oxide in the borosilicate glass base material be 10% by weight or less, preferably 5% by weight or less.

Further, as the refractory raw material, silicic acid (SiO ₂ ) or alumina (Al ₂ O ₃ ) can be mainly used. However, when the content of alumina is too large, the fire resistance is too high. As a result, sufficient sintering cannot be obtained and whitening and opacity progress. Therefore, No. 1 obtained by using such a borosilicate glass base material. 5 or No. In the inorganic artificial ceramic of No. 6, the luminous characteristics are reduced, the mechanical properties and the durability are also reduced, and the phosphorescent brightness after the weathering process is lower than before the weathering process. is there.

In the borosilicate glass base material: F, which has an extremely high alumina content of 22.88% by weight, sodium oxide (Na ₂ O) and phosphoric acid (P ₂ Even if the content of O5) is extremely large, sufficient sintering cannot be obtained, and opaque whitening occurs. In the inorganic artificial ceramic of No. 6, the light emission characteristics (phosphorescence luminance) are extremely reduced, and the light emission characteristics after the weathering test are significantly reduced.

Further, oxides of transition metals such as Fe, Cr, Ni, Co, and Cu impair light emission characteristics, such as lowering the light emission luminance of the phosphor and causing color change of light emission. However, it is desirable to keep the content low, and in this embodiment, the content is 0.01% by weight to 0.0% by weight.
Although a borosilicate glass base material containing 4% by weight of Fe ₂ O ₃ was used, the total content of these transition metal oxides was 1.
When the content exceeds 0% by weight, the emission luminance starts to decrease sharply.
When it reaches 5% by weight, the emission luminance is 50% of that of high purity.
It is desirable that the total content of the transition metal oxide be 1.0% by weight or less because the content falls below.

Example 2 In the same manner as in Example 1, 30% by weight of the luminous phosphor obtained by adding europium as an activator to strontium aluminate and the boron produced in Example 1 were added. Silicate glass base material: 70% by weight of A was mixed in a powder state, and then fired under firing temperature conditions shown in Table 3 below to obtain various inorganic artificial ceramics. Then, these characteristics were examined in the same manner as in Example 1, and the results are shown in Table 3 below.

[0042]

[Table 3]

As is clear from the results shown in Table 3, when the inorganic artificial ceramics are manufactured using the borosilicate glass base material: A, the firing temperature is 800.
Under the condition of ° C., the phosphorescent brightness was lower than that under other firing temperature conditions. This may be because the firing temperature is rather low, so that a sufficient protective layer cannot be formed on the surface of the phosphorescent phosphor dispersed and contained.

The inorganic artificial ceramics obtained by firing at a temperature of 820 ° C. or more is sufficiently sintered, and can improve mechanical properties, abrasion resistance, and durability. The phosphorescent brightness was also large. Further, the phosphorescent phosphor contained in the obtained inorganic artificial ceramics also had good oxidation resistance and the like.

However, in the case of the inorganic artificial ceramics (Example 6 of the present invention) obtained by firing under the temperature condition of 850 ° C., although the denseness is certainly improved, the firing temperature condition is slightly too high, It is recognized that the luminous luminance is slightly lowered due to the oxidative decomposition of the phosphorescent phosphor in the process. Therefore, as the firing temperature conditions for obtaining the inorganic artificial ceramics, it is desirable to control the atmosphere during firing so that the emission luminance does not decrease due to the oxidative decomposition of the phosphor.

Example 3 In the same manner as in Example 1, the luminous phosphor composed of strontium aluminate and europium as an activator was added to the borosilicate glass base material A produced in Example 1 above. The contents were mixed as shown in Table 4 below, and the obtained mixture was baked at 820 ° C. for 30 minutes to obtain a desired inorganic artificial ceramic. The properties of the obtained inorganic artificial ceramics were examined in the same manner as in Example 1, and the results are shown in Table 4 below.

[0047]

[Table 4]

As is evident from the results shown in Table 4, as the phosphor content increases, the phosphorescence luminance of the ceramics increases, but when the phosphor content exceeds 50% by weight. On the contrary, it is recognized that the phosphorescent luminance is reduced. The reason is that, as the content of the phosphor increases, the relative amount of the borosilicate glass base material to the phosphor decreases, and it becomes difficult to coat the phosphor with the borosilicate glass base material. It is considered that the phosphor is oxidatively decomposed in the firing process.

Example 4 First, in the same manner as in Example 1, 30% by weight of the phosphorescent phosphor composed of strontium aluminate and europium as an activator, and the borosilicate glass base material manufactured in Example 1 were used. Material: A mixture obtained by mixing 70% by weight of A was shaped, granulated, and then fired to produce a granulated product of No. 6 inorganic artificial ceramics. On the other hand, after melting the mixture of the phosphorescent phosphor and the borosilicate glass base material,
The mixture was cooled, and the obtained mass was pulverized to prepare pulverized inorganic artificial ceramics of each particle size. Then, the phosphorescence luminance of the obtained granulated product or pulverized product was measured, and the results are shown in Table 5 below. The particle size ranges are also shown in Table 5 below.

[0050]

[Table 5]

As shown in Table 5, the pulverized product tended to have slightly lower phosphorescent brightness than the granulated product. In addition, the pulverized product showed a tendency that the phosphorescent luminance decreased as the particle size became finer. More specifically, 1.5
crushed products under 0.5 mm or 0.5 mm, especially 0.
In the case of a pulverized product under 5 mm, the phosphorescent luminance is significantly reduced. Specifically, in the case of fine powder under 1.5 mm, the phosphorescent luminance is reduced to about 1/5 and 0.5 m
It has been clarified that the fine powder of m-under is reduced to about 1/15.

Embodiment 5 This embodiment shows an example in which a stop line at a road intersection is actually formed using the inorganic artificial ceramics according to the present invention according to the neat method.

First, as a phosphorescent phosphor, strontium aluminate (SrAl ₂ O ₄ ) having a long-term afterglow characteristic is used.
On the other hand, a phosphor prepared by mixing europium (Eu) as an activator and having an appropriate particle size so as not to impair the emission characteristics was prepared. Then, a mixture of 70% by weight of the borosilicate glass base material A produced in Example 1 and 30% by weight of the phosphorescent phosphor was used.
After firing at 850 ° C. for 30 minutes, the mixture was allowed to cool in a furnace to produce a target inorganic artificial ceramic.

Next, the inorganic artificial ceramics obtained above was pulverized and sieved to obtain a particle size of 3.3 to 3.0.
It was prepared A ₁ grain of 2.0 mm. With A ₁ grain of the resulting ceramic, to form a stop line according neat method. Note that a methyl methacrylate (MMA) resin was used as the binder resin, and the amount used was 1.5 kg per 1 m ² . The amount of the inorganic artificial ceramic used was set to 6 kg per 1 m ² .

Then, the fluorescence emission property and the phosphorescence emission property of the stop line formed above were evaluated respectively.
In addition, the fluorescent light emission irradiates the headlight of the car from a place 10 m away from the stop line at night, and the light emission is determined by the naked eye, and the phosphorescent light emission is 10 m away from the stop line at night. After illuminating the car's headlights from the place for 4 minutes, it turns off, and 2 minutes after that,
It was judged with the naked eye.

As a result, the stop line formed by using the inorganic artificial ceramics according to the present invention exhibited good fluorescence and excellent phosphorescence while exhibiting excellent phosphorescent properties. It is understood that the stop line formed by using the ceramics can exhibit good light emission characteristics both at the time of irradiation and at the time of extinguishing, and the visibility of the stop line is significantly improved. .

The ceramics used are:
As in the present embodiment, not only the inorganic artificial ceramics according to the present invention, but also those mixed at various mixing ratios with conventionally known fluorescent inorganic artificial ceramics and various natural ceramics, artificial ceramics and the like are used. It goes without saying that it can be done.

Example 6 In this example, the light emission characteristics of a glass plate-shaped inorganic artificial ceramic are examined. The phosphor used was the phosphorescent phosphor shown in Example 1 and strontium aluminate to which europium was added as an activator, and the borosilicate glass base material was as shown in Table 1 above.
The borosilicate glass base material shown in FIG.

Generally, strontium aluminate, which is a component of the phosphorescent phosphor, has high fire resistance.
When the content of the phosphorescent phosphor is about 25% by weight or more, the obtained inorganic artificial ceramic has a structure like a sintered body. Therefore, in order to obtain the inorganic artificial ceramics as a transparent glass-like body as in this embodiment, the content of the phosphorescent phosphor is desirably 20% by weight or less.

Therefore, in this embodiment, first, 15% by weight of the phosphorescent phosphor and 85% by weight of the borosilicate glass base material are mixed, and the temperature is raised to 850 ° C. in the crucible and melted. After that, it was left for 30 minutes. Then, the obtained melt was flowed out onto a metal plate and flattened by a roller to obtain a 3 mm-thick translucent glass plate-like inorganic artificial ceramic having luminous fluorescent characteristics.

The inorganic artificial ceramics (sample) obtained above is irradiated with light from a halogen lamp,
The phosphorescence brightness was measured. In addition, about phosphorescent brightness,
After irradiating light for 4 minutes from a light source for measurement (halogen lamp, illuminance: 1000 lux) installed in the vertical direction with respect to the horizontal plane of the sample, the phosphorescence brightness immediately after the irradiation and the phosphorescence 2 minutes after the irradiation is completed The luminance was measured by a light receiver 1 arranged at a predetermined position in the direction of 45 ° above the sample and a light receiver 2 arranged at a predetermined position opposite to the light source for measurement with the sample interposed therebetween (see FIG. 2). The results are shown in Table 6 below.

[0062] However, mcd / m ² : millicandela / m ²

As is evident from the results shown in Table 6, a higher phosphorescent luminance was measured in the light receiver 2 although it was inferior to the light receiver 1. The reason for this is that the glass plate-shaped inorganic artificial ceramics obtained in this example is translucent and has excellent translucency.
It is conceivable that the light from the measurement light source could advantageously reach not only the light receiving surface but also the back surface. Therefore, it is understood that the glass plate-shaped inorganic artificial ceramics obtained in this example can be advantageously used also as a lantern type glass plate having a light source therein.

[0064]

As is apparent from the above description, according to the inorganic artificial ceramics having luminous fluorescent properties according to the present invention, the emission luminance by fluorescence and phosphorescence is high, and the mechanical strength, abrasion resistance, Alternatively, since the weather resistance and the like are extremely good and have excellent durability performance, the deterioration of the fluorescent characteristics can be effectively suppressed, and it can be used widely and advantageously for various uses.

Moreover, in the inorganic artificial ceramics having the luminous fluorescent property according to the present invention, the total content of the alkaline earth metal oxides and the total content of the transition metal oxides are not more than predetermined amounts. By doing so, more excellent light emitting characteristics can be advantageously exhibited.

Further, according to the method for producing an inorganic artificial ceramic having a luminous fluorescent characteristic according to the present invention, the decomposition of the luminous phosphor during firing can be effectively reduced, and the luminous characteristic and the durability as described above can be reduced. This makes it possible to advantageously produce inorganic artificial ceramics having excellent luminous fluorescent properties.

[Brief description of the drawings]

FIG. 1 is a schematic explanatory view of an apparatus for measuring the phosphorescence luminance of an inorganic artificial ceramic according to the present invention.

FIG. 2 is a schematic explanatory view of another apparatus for measuring the phosphorescent luminance of the inorganic artificial ceramics according to the present invention.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification code FI C09K 11/64 CPM C04B 35/00 H (72) Inventor Toyohiko Tsukada 11-4 Shiogusa-cho, Seto-shi, Aichi Pref. In-company (72) Inventor Takeshi Naruse 11-11 Shiogusa-cho, Seto-shi, Aichi Pref. Examiner, Yuichi Fukakusa, inside and outside Ceramics Co., Ltd. (56) References JP-A-8-165140 (JP, A) JP-A-63 -252939 (JP, A) JP-A-9-142882 (JP, A) JP-A-49-96783 (JP, A) (58) Fields investigated (Int. Cl. ⁷ , DB name) C03C 4/12 C03C 3/064 C03C 3/089 C09K 11/00

Claims (7)

(57) [Claims] 1. A relative SiO _2, B ₂ O _3, and borosilicate glass matrix mainly comprising alkali metal oxides, the general formula: MO-nAl ₂ O ₃ (where, M is magnesium, calcium, Represents one metal selected from the group consisting of strontium and barium or two or more composite metals), and comprises 3 to 50% by weight of a phosphorescent phosphor particle comprising at least one metal aluminate salt represented by the following formula: Melting or firing at a content of
By, <br/> is accumulating light phosphor particles該硼silicate glass base material uniformly dispersed, it is constituted by granules comprising been made to contain
The phosphorescent phosphor particles are wrapped in the borosilicate glass matrix.
An inorganic artificial ceramic granular product having luminous fluorescent properties, characterized in that it is isolated from the outside in a packed form . 2. The inorganic artificial ceramic particles having luminous fluorescent properties according to claim 1, wherein the luminous phosphor contains an activator or a co-activator together with the activator .
Goods . 3. The inorganic artificial ceramic granules having luminous fluorescent characteristics according to claim 1, wherein the borosilicate glass base material has a melting point of 1000 ° C. or less .
Goods . 4. The total content of alkaline earth metal oxides in the borosilicate glass base material is 10% by weight or less, and the total content of transition metal oxides is 1.0% by weight or less. 1
An inorganic artificial ceramic granular product having luminous fluorescent characteristics according to any one of claims 3 to 3. 5. The phosphorescent phosphor in the borosilicate glass base material.
Granular material in which light particles are uniformly dispersed and contained
Is a mixture of the borosilicate glass base material and the phosphorescent phosphor particles.
By firing the granulated product
An inorganic artificial ceramic according to any one of claims 1 to 4.
Box granular products. 6. The phosphorescent phosphor in the borosilicate glass base material.
Granular material in which light particles are uniformly dispersed and contained
Is a mixture of the borosilicate glass base material and the phosphorescent phosphor particles.
Lump or large chunks formed by melting or firing
Crushed and sieved to remove fine particles less than 0.5 mm
The method according to any one of claims 1 to 4, which is obtained by
The granular product of the inorganic artificial ceramic according to 1. 7. A borosilicate glass base material containing SiO ₂ , B ₂ O ₃ and an alkali metal oxide as main components,
At least one alumina represented by the general formula: MO-nAl ₂ O ₃ (where M represents one kind of metal selected from the group consisting of magnesium, calcium, strontium, and barium or two or more kinds of composite metals) What blended the particles of phosphorescent phosphor composed of acid metal salt,
Firing at a temperature of 750 ° C to 900 ° C in an inert atmosphere or a weak reducing atmosphere
By the above, the phosphorescent phosphor particles in the borosilicate glass base material
Enclosed and isolated from the outside , the phosphorescent phosphor has a phosphorescent phosphorescent property characterized in that the phosphorescent phosphor is uniformly dispersed and contained in the borosilicate glass base material as a granular material of a sintered body. A method for producing an inorganic artificial ceramic granular product .