JP2021031354A - Luminescent glass - Google Patents

Abstract

To provide a luminescent glass that has high acid resistance and high water resistance, and has excellent processability so as to be processed in a desired shape.SOLUTION: A luminescent glass contains 5 mass% or more and 60 mass% or less of P2O5, and 30 mass% or more and 80 mass% or less of Nb2O5, and includes an Eu component as the luminescent center.SELECTED DRAWING: None

Description

The present invention relates to a luminescent glass in which the glass itself emits light.

A light source using a light emitting diode is attracting attention as an illumination light source to replace fluorescent lamps and incandescent lamps. As a material for light emitting diode illumination, light emitting glass excited by near-ultraviolet rays is considered to be useful. As such glass materials, _{luminescent glass (Patent Document 1) containing B 2} O ₃ and MO (M indicates a Group 2 element) and having Cu clusters and the like, and glass ceramics containing an Eu component (Patent Document 1). Patent Document 2) has been proposed.

However, light-emitting glass described in Patent Document 1 contains a large amount of B ₂ O _3, not only the easy phase separation, is not sufficient chemical durability. Further, since the material described in Patent Document 2 is glass ceramics, a glass piece is produced and then heat-treated to precipitate crystals. Therefore, there is a problem that the manufacturing process becomes complicated.

Japanese Unexamined Patent Publication No. 2014-133682 Japanese Unexamined Patent Publication No. 2007-197249

An object of the present invention is to provide a luminescent glass having high acid resistance and water resistance and excellent workability so that a desired shape can be easily obtained.

The present inventors have discovered that a glass obtained by adding an Eu component to _{a P 2} O _5- Nb ₂ O ₅ system glass having high acid resistance and high water resistance has fluorescence characteristics, and has reached the present invention. The present invention includes the following.
_{[1] A light emitting glass containing P 2} O _{5 of 5} % by mass or more and 60% by _{mass or less and Nb 2} O _{5 of} 30% by mass or more and 80% by mass or less, and emitting an Eu component as a light emitting center. Glass.
[2] The luminescent glass according to [1], which contains _{TiO 2} of 1% by mass or more and 30% by mass or less.
[3] _{The luminescent glass according to [1] or [2], which contains Li 2} O, Na ₂ O and K ₂ O in a total amount of more than 0% by mass and 30% by mass or less.
[4] The luminescent glass according to any one of [1] to [3], which emits light having a maximum wavelength between 570 nm and 700 nm by irradiation with light of 350 to 420 nm.

The luminescent glass of the present invention is a luminescent glass having high acid resistance and high water resistance and excellent workability. Therefore, it has the advantage that it can be used outdoors and it is easy to process it into a special shape.

FIG. 1 shows the measurement results (excitation wavelength 394 nm) of the fluorescence spectra of the glasses of Example 1 and Reference Example. FIG. 2 shows the measurement results (fluorescence wavelength 612 nm) of the excitation spectra of the glasses of Example 1 and Reference Example.

The light emitting glass of the present invention is a glass having fluorescence characteristics that can emit light by itself by irradiating light having a predetermined wavelength. First, the glass components constituting the light emitting glass will be described. In this specification, the content of the glass component is expressed in "mass%" based on the oxide.

[Glass component]
The luminescent glass of the present embodiment is a P ₂ O _5- Nb ₂ O ₅ system mother glass containing Eu. By using it as a mother glass of P ₂ O _5- N ₂ O ₅ system, it is possible to provide a light emitting glass that emits Eu light and has excellent acid resistance, water resistance, and processing characteristics.

(Mother glass)
Mother glass luminescent glass of the present embodiment includes a P ₂ O ₅ ingredient as a network former. P ₂ O ₅ is an essential component that also forms the skeleton of glass.
P ₂ O ₅ is contained as a glass skeleton in a proportion of 5% by mass or more and 60% by mass or less. When _{the content of P 2} O ₅ is 5% by mass or more, devitrification is difficult, and when it is 60% by mass or less, water resistance and acid resistance can be improved, and an increase in glass transition temperature is suppressed. And press molding is possible.
The lower limit of P ₂ O ₅ is preferably 8% by mass or more, more preferably 10% by mass or more, further preferably 12% by mass or more, and even more preferably 15% by mass or more.
The upper limit of P ₂ O ₅ is preferably 55% by mass or less, more preferably 50% by mass or less, further preferably 45% by mass or less, and even more preferably 40% by mass or less.

The luminescent glass of the present invention contains _{Nb 2} O ₅ in a proportion of 30% by mass or more and 80% by mass or less. If it is 30% by mass or more, water resistance and acid resistance can be improved, while if it is 80% by mass or less, problems such as coloring and devitrification are less likely to occur.

The lower limit of Nb ₂ O ₅ is preferably 35% by mass or more, more preferably 37% by mass, and even more preferably 40% by mass or more.
The upper limit of Nb ₂ O ₅ is preferably 75% by mass or more, more preferably 70% by mass, and even more preferably 65% by mass or more.

The luminescent glass of the present invention has TiO ₂ , Bi ₂ O ₃ , BaO, Ta ₂ O ₃ , WO ₃ , ZnO, Geo ₂ , La ₂ O ₃ , Y ₂ O ₃ , Gd ₂ O ₃ , and In as optional components. ₂ O _3, it may include one or the plurality of kinds of TeO _2.

As these components, _{the lower limit of the content of TiO 2} is preferably 1% by mass or more, and more preferably 3% by mass or more, from the viewpoint of improving stability, water resistance, and acid resistance.
Further, _{from the viewpoint of transmittance and stability, the upper limit of the content of TiO 2} is preferably 30% by mass or less, and more preferably 20% by mass or less.

Bi ₂ O ₃ , BaO, Ta ₂ O ₃ , WO ₃ and ZnO can be contained as optional components. Bi ₂ O ₃ , BaO, Ta ₂ O ₃ , WO ₃ and ZnO can be contained as long as the effects of the light emitting glass of the present invention are not impaired. Each component of Bi ₂ O ₃ , BaO, Ta ₂ O ₃ , WO ₃ and ZnO may be contained, for example, 0.1% by weight or more, 0.5% by weight or more, 1% by weight or more and 3% by weight or more. it can. The upper limit can be, for example, 20% by weight or less, 15% by weight or less, and 10% by weight.

Further, for the purpose of lowering the melting temperature of the glass and the liquidus temperature (LT) of the glass, the luminescent glass of the present embodiment is selected from the group consisting of _{Li 2} O, Na ₂ O and K _{2 O.} It is preferable that one or more kinds of alkali metal oxides are contained. However, if _{the total content of Li 2} O, Na ₂ O and K ₂ O exceeds 30% by mass, devitrification may occur easily. Therefore, _{the total content of Li 2} O, Na ₂ O and K ₂ O is preferably 30% by mass or less. Further, the lower limit is preferably contained in an amount of more than 0% by mass, more preferably 1% by mass or more.
As each component, _{the preferable content of Li 2} O is 0% by mass or more and 1% by mass or less. The preferable content of Na ₂ O is 0% by mass or more and 30% by mass or less, preferably 1% by mass or more and 20% by mass or less. The preferable content of K ₂ O is 0% by mass or more and 30% by mass or less, and more preferably 1% by mass or more and 20% by mass or less.
As the alkali metal oxide, it is preferable that Na ₂ O only, K ₂ O only, or Na ₂ O and K ₂ O are contained, and Na ₂ O and K ₂ O are further contained. preferable.

Further, for the purpose of lowering the liquidus temperature (LT) of the glass and improving the devitrification resistance, the optical glass of the present embodiment may contain an appropriate amount of CaO and SrO as optional components. However, if the contents of CaO and SrO are excessive, the desired water resistance and acid resistance may not be obtained. The contents of CaO and SrO can be, for example, 0% by mass or more and 6% by mass or less, 0% by mass or more and 5% by mass or less, and 0% by mass or more and 4% by mass or less, respectively. ..

Further, for the purpose of improving the devitrification resistance, the light emitting glass of the present embodiment may contain an appropriate amount of _{B 2} O _3. In particular, when the glass containing _{P 2} O ₅ , Nb ₂ O ₅ and TiO _{2 contains an appropriate amount of B 2} O ₃ , the devitrification resistance can be significantly improved. However, if the amount of B ₂ O ₃ component is too large, the water resistance and acid resistance may deteriorate. Therefore, _{the lower limit of the B 2} O ₃ component is preferably 0% by mass or more, more preferably more than 0% by mass, still more preferably 1% by mass or more, and the upper limit is preferably 12% by mass or less, more preferably. Is 10% by mass or less.

Further, the light emitting glass of the present embodiment _{may contain SiO 2} and ZrO ₂ as optional components. By containing a small amount of SiO ₂ and ZrO ₂ in the optical glass, coloring can be further reduced and devitrification resistance can be improved. However, if the content is too large, the devitrification resistance may deteriorate. Therefore, _{the content of SiO 2} is preferably 0% by mass or more and 4% by mass or less, more preferably 0% by mass or more and 2% by mass or less, and _{the content of ZrO 2} is preferably 0% by mass or more and 4% by mass or less. , 0% by mass or more and 2% by mass or less is more preferable. _{Further, components such as La 2} O ₃ , Y ₂ O ₃ , Gd ₂ O ₃ , MgO, and Cs ₂ O can be added to the optical glass of the present embodiment as long as the object of the present invention is not impaired. Is.

If necessary, the fining agent may contain Sn oxide, Ce oxide and Sb oxide. Among Sn oxides, Ce oxides, and Sb oxides, Sb oxides are preferably used, and the content is Sb ₂ O ₃ , and the lower limit is preferably 0.0001% by mass or more, more preferably 0.0001% by mass or more. , 0.0005% by mass or more, more preferably 0.001 or more, and the upper limit is preferably 0.1% by mass or less, more preferably 0.01% by mass or less, still more preferably 0.005% by mass or less. Is.

(Eu component)
The light emitting glass of the present invention contains an Eu component (Eu ₂ O ₃ ) as a light emitting center. _{By incorporating Eu 2} O ₃ in the mother glass, the light emitting glass can emit light by irradiating it with light having a predetermined wavelength.

In the light emitting glass of the present embodiment, _{the content of Eu 2} O ₃ is preferably 0.005% by mass or more, more preferably 0.05% by mass or more, based on the outer composition of the mother glass.
On the other hand, it is preferably 5% by mass or less, and more preferably 3% by mass or less with respect to the mother glass.

(Production method)
The luminescent glass of the present invention can be obtained by blending, melting, and molding a glass raw material. As the glass raw material, for example, phosphates containing glass components, carbonates, nitrates, sulfates, borates, metal oxides, orthophosphoric acid and the like may be used. As for the glass melting method and molding method, a known method may be used.

(Illumination light)
The light emitting glass of the present embodiment is a glass that emits light by irradiating light having a predetermined wavelength. Specifically, the light to be irradiated may have a wavelength that can excite the glass, and this is not particularly limited. The wavelength at which the luminescent glass of the present embodiment can be excited can be found by measuring the excitation spectrum. As can be seen from FIG. 2 showing the excitation spectrum of the glass of Example 1 described later, the light emitting glass of the present invention can excite the light emitting glass particularly with light of 350 nm to 420 nm. Further, as can be seen from FIG. 1 showing the fluorescence spectrum, light having a wavelength of at least 394 nm exhibits emission having a wavelength of 570 nm to 700 nm. Therefore, for example, even natural light (sunlight) having a wavelength of 394 nm or the like can excite the light emitting glass of the present embodiment as long as it contains light having a wavelength that excites the glass. In order to emit light efficiently, only light having a wavelength of 350 nm to 420 nm may be irradiated.

The irradiation time for irradiating the irradiation light is not particularly limited as long as the luminescent glass can be excited. Normally, light emission starts as soon as it is irradiated with light that can be excited.

(Light emission)
The light emitted from the light emitting glass of the present invention is red to pink as described above. As the wavelength of the light to be emitted, light having a wavelength of 570 nm to 700 nm is emitted. The wavelength of the emitted light is a wavelength having a maximum value between 570 nm and 700 nm.

(Light emission time)
The light emitting time of the glass of this embodiment is not particularly limited, and after emitting light for a predetermined time, the light emission ends. Therefore, it is presumed that when the excited state ends, the light emission ends.

(Water resistance / acid resistance)
The glass of the present embodiment has good water resistance and acid resistance as a light emitting glass. Since it has good water resistance and acid resistance, it can be used more effectively than other luminescent glasses when used outdoors. The glass of the present embodiment is preferably first-class in both water resistance and acid resistance in the standard of the Japan Optical Glass Industry Association standard JOGIS06-2009.

(Workability)
The glass of the present embodiment has an excellent workability. The glass of the present embodiment preferably has a degree of wear (standard of Japan Optical Glass Industry Association standard JOBIS10-1994), which is one of the indexes of workability, of 150 to 350. When the degree of wear is in this range, it is preferable because it has the minimum necessary rigidity and high workability.

(Use)
Light of such a wavelength is useful for applications such as lasers and displays.

Examples The present invention will be further described below with reference to Examples. The present invention is not limited to the examples.

The glass of this example uses raw materials such as optical glass-grade high-purity phosphates, oxides, hydroxides, carbonates, nitrates, chlorides, sulfates, and orthophosphoric acid, and is carried out in Table 3. The raw materials were weighed and mixed so as to obtain a glass having the composition of Example 1 to prepare a blending raw material. Next, each compounded raw material was placed in a platinum crucible, heated to 1000 to 1450 ° C., melted, stirred and homogenized, allowed to stand for clarification, and then poured into a mold. After the glass solidified, it was then transferred to an electric furnace heated near the slow cooling point of the glass and slowly cooled to room temperature. In this way, the block made of the glass of Example 1 shown in Table 3 was produced. A test piece necessary for measurement was cut out from the obtained glass block. Further, as a reference example, a glass having a composition not containing Eu of the glass of Example 1 (reference example) and Comparative Examples 1 and 2 were produced in the same manner.

The method for measuring each physical property of glass is as follows.
Powder method acid resistance: The acid resistance of the glass of Reference Examples and Comparative Examples 1 and 2 is determined in accordance with the Japan Optical Glass Industry Association Standard JOBIS-06 2009 "Measuring Method of Chemical Durability of Optical Glass (Powder Method)". It was measured. Specifically, the acid resistance test will be described in a quartz glass round-bottom flask containing powdered glass (particle size 425-600 μm) having a weight corresponding to the specific gravity in a platinum basket and containing a 0.01 mol / L nitrate aqueous solution. Was immersed in, treated in a boiling water bath for 60 minutes, the weight loss rate Da (%) before and after the treatment was measured, and the obtained values were classified based on Table 1. The grade of each glass is shown in Table 3.
Water resistance by powder method: The water resistance of the glass of Reference Examples and Comparative Examples 1 and 2 is determined in accordance with the Japan Optical Glass Industry Association Standard JOGIS-06 2009 "Measuring Method of Chemical Durability of Optical Glass (Powder Method)". It was measured. Table 3 shows the grades of water resistance of the powder method. Specifically, the water resistance test is described by placing powdered glass (particle size 425-600 μm) having a weight corresponding to the specific gravity in a platinum basket, immersing it in a quartz glass round-bottom flask containing pure water, and boiling it. The treatment was carried out in a water bath for 60 minutes, the weight loss rate Dw (%) before and after the treatment was measured, and the obtained values were classified based on Table 2. The grade of each glass is shown in Table 3.

Evaluation of processing characteristics (wear degree): The wear degree of the glass of the reference example was measured according to the Japan Optical Glass Industry Association standard JOGIS-10 1994 "Measurement method of the wear degree of optical glass". Table 3 shows the degree of wear of each glass.

Measurement of light wavelength: Spectral fluorescence photometry was performed on the glass of Example 1 and Reference Example using light of 394 nm as excitation light. The results are shown in FIG. 1 (in the figure, the glass of Example 1 is referred to as "Example").

Since the glass of Example 1 is obtained by adding only 0.1% by weight of the Eu component to the reference glass by external division, the glass characteristics described in the table other than the fluorescence characteristics of Example 1 are substantially reference. It can be considered equivalent to glass.

Comparative Example 1 is common to Patent Document 1 in that it is a glass having _{B 2} O ₃ as a network homer, although the composition itself is different. Compared with the glass of Example 1 (reference example), the result is poor acid resistance.
Comparative Example 2 is a P ₂ O ₅ glass, but does not contain _{Nb 2} O _5. Since _{it does not contain Nb 2} O ₅ , the acid resistance is inferior.

Claims (4)

_{A luminescent glass containing P 2} O _{5 of 5} % by mass or more and 60% by _{mass or less and Nb 2} O _{5 of} 30% by mass or more and 80% by mass or less, and containing an Eu component as a light emitting center. The luminescent glass according to claim 1, which contains _{TiO 2} of 1% by mass or more and 30% by mass or less. The luminescent glass according to claim 1 or 2, which contains Li ₂ O, Na ₂ O, and K ₂ O in a total amount of more than 0% by mass and 30% by mass or less. The luminescent glass according to any one of claims 1 to 3, which emits light having a maximum wavelength between 570 nm and 700 nm by irradiation with light of 350 to 420 nm.