JP5316232B2 - Method for producing phosphor-dispersed glass - Google Patents

Description

  The present invention relates to a method for producing a phosphor-dispersed glass.

  DESCRIPTION OF RELATED ART Conventionally, the light emitting diode light source provided with the glass which disperse | distributed the fluorescent substance which converts the light-emitting element which light-emits with a predetermined color and the light emitted from a LED light-emitting element into the light of a desired color is known.

  For example, it is possible to create a light emitting diode light source that emits white light by mixing blue and yellow using an LED light emitting element that emits blue light and a phosphor that converts the blue light to yellow.

  At this time, in order to obtain white light emission with a uniform color tone, phosphor light-emitting glass in which the phosphor is uniformly dispersed in a transparent resin (glass) is used, and light is emitted from the LED light emitting element in this glass body. It is important to uniformly mix blue and yellow emitted from the phosphor to uniformly emit white light, which is mixed color, outside the glass body.

  In addition, glass powder of a predetermined particle size and phosphor powder are mixed and sintered to synthesize blue light emitted from a blue light source and yellow converted by the phosphor to obtain white light, and blue with strong energy There has already been proposed a luminescent color conversion member that improves reliability by using a stable glass that does not change color with respect to light and has a small temperature rise (see, for example, Patent Document 1).

  The luminescent color conversion member and the conventional phosphor-dispersed glass described in Patent Document 1 are manufactured by, for example, the manufacturing method shown in FIG.

  First, glass powder 1 and phosphor powder 2 are mixed in a mixing step, and resin binder 3 is added thereto to produce mixed material 10A in which glass powder 1 and phosphor powder 2 are uniformly mixed. Next, the preform 15 is generated by pressure molding using a mold having a predetermined shape. Then, the phosphor-dispersed glass 20 which is a homogeneous scatterer is manufactured by firing at a predetermined temperature in a sintering process. Further, in this sintering step, the resin binder 3 added when the mixed material 10A is generated is removed.

Japanese Patent No. 4158012

  In the manufacturing method using the resin binder described above, the glass powder and the phosphor powder are uniformly mixed using the resin binder and can be molded into any desired shape. This is preferable as a method for producing body-dispersed glass. However, this manufacturing method includes a step of forming a preform by adding a resin binder and a step of firing and sintering until the resin binder is removed, and the production process is complicated and laborious.

  In addition, since the resin binder is removed in the sintering process, if there are concerns about adverse effects on the environment, post-treatment of the removed resin binder is required, and the phosphor-dispersed glass can be used without using the resin binder. It is desirable to manufacture.

  Therefore, the present invention can mix and sinter glass powder and phosphor powder without using a resin binder, and can uniformly emit light with mixed color light in which the light from the LED light emitting element and the light from the phosphor are superimposed. An object of the present invention is to provide a method for producing a phosphor-dispersed glass.

To accomplish the above object, a predetermined phosphor is dispersed, the phosphor primary light for emitting the light - emitting element is converted into another color of the secondary light, the primary light and the secondary light Is a method for producing a phosphor-dispersed glass that produces third light in which a glass particle having a maximum particle diameter of 160 μm or more and a median diameter d50 of 5 μm or more and a predetermined amount of phosphor a mixing step of mixing a powder, and heating the mixture under pressure is characterized in that a heating pressure forming step of molding into a predetermined shape.

If it is said structure, a phosphor can be disperse | distributed with a predetermined density to such an extent that a favorable scatterer can be formed, without using a resin binder, and primary light which a light emitting element ( LED light emitting element ) light-emits is emitted. A phosphor-dispersed glass that scatters well, mixes the primary light and secondary light emitted from the phosphor well, uniforms the color of light emission, does not cause color shift, and emits light of a desired color. A manufacturing method can be obtained.

  The present invention is also characterized in that, in the method for producing a phosphor-dispersed glass having the above-described configuration, the amount of the phosphor powder is 0.02 to 12% by volume ratio. According to this configuration, the amount of secondary light to be converted is not too low, and the phosphor-dispersed glass capable of emitting light with desired third light is manufactured by setting the amount so as not to inhibit light transmission. Can do.

  The present invention is also characterized in that, in the method for producing a phosphor-dispersed glass having the above structure, the amount of the phosphor powder is 0.05 to 5% by volume. According to this configuration, it is possible to produce a phosphor-dispersed glass that can emit light with better third light.

  According to the present invention, in the method for producing a phosphor-dispersed glass having the above-described configuration, the phosphor is an oxide phosphor that is stable at a heating temperature at which the glass is heated and pressed. According to this configuration, even if the glass is sintered by heat and pressure molding, the phosphor remains in a stable state, so that it exhibits a predetermined fluorescence function and emits uniform secondary light with a uniform color tone. A phosphor-dispersed glass capable of emitting light can be produced.

The present invention is in the production method of the phosphor dispersion glass having the above structure, before Symbol Luminous element blue light emitting device, the phosphor is a yellow phosphor, it is characterized in that the third light is white Yes. According to this configuration, it is possible to manufacture a phosphor-dispersed glass that emits white light having a uniform color tone.

According to the present invention includes a mixing step of mixing a phosphor powder having a predetermined glass powder and a predetermined amount of the particle diameter, and heating the mixture, pressurizing and heating press-molding step of molding into a predetermined shape Since the phosphor-dispersed glass manufacturing method is used, the phosphor can be dispersed at a predetermined density to the extent that a good scatterer can be formed without using a resin binder, and the light-emitting element ( LED light-emitting element ) The primary light emitted is scattered well, the primary light and the secondary light emitted from the phosphor are mixed well to make the emission color uniform, and no color shift occurs, and light emission of a desired color is possible. A phosphor-dispersed glass can be produced.

It is a schematic explanatory drawing of the manufacturing method of the fluorescent substance dispersion | distribution glass concerning this invention. It is a schematic explanatory drawing of the manufacturing method of the conventional fluorescent substance dispersion | distribution glass. It is a schematic explanatory drawing of an example of the fluorescent substance dispersion glass obtained by the manufacturing method of the fluorescent substance dispersion glass which concerns on this invention. It is sectional drawing which shows the example of a shape of fluorescent substance dispersion | distribution glass, (a) is an example of plate shape, (b) is an example of convex lens shape, (c) is an example of convex plate shape.

  Embodiments of the present invention will be described below with reference to the drawings. Moreover, the same code | symbol is used about the same component and detailed description is abbreviate | omitted suitably.

  First, the manufacturing method of the fluorescent substance dispersion | distribution glass which concerns on this embodiment is demonstrated using FIG.

  In the method for producing the phosphor-dispersed glass according to the present embodiment, the mixing step S1 in which the glass powder 1 having a predetermined particle diameter and the predetermined amount of the phosphor powder 2 are mixed, and the mixed powder 10 created in the mixing step is heated. A heating and pressing molding step S2 for obtaining phosphor-dispersed glass by pressure molding.

  In the mixing step S1, glass powder 1 having a predetermined particle diameter and a predetermined amount of phosphor powder 2 are uniformly mixed without using a conventionally used resin binder. Thus, by uniformly mixing a predetermined amount of the phosphor powder 2 with the glass powder 1 having a predetermined particle diameter, the phosphor powder 2 can be formed to such an extent that a good scatterer can be formed without using a resin binder. It can be dispersed at a predetermined density.

  Any phosphor can be used as long as it is commercially available. For example, sulfide phosphor, oxysulfide phosphor, halide phosphor, oxide phosphor, nitride phosphor, oxynitride phosphor, aluminate phosphor, α sialon phosphor, β sialon phosphor The body can be used. However, since a stable phosphor is preferable in the heat and pressure molding process, it is preferable to use an oxide phosphor that is stable at the heating temperature at which the glass is heat and pressure molded.

  For example, as raw materials for Y, Gd, Ce, Sm, Al, La, and Ga, oxides or compounds that easily become oxides at high temperatures are used, and these are sufficiently mixed in a stoichiometric ratio to obtain raw materials. . Alternatively, a coprecipitated oxide obtained by calcining a solution obtained by coprecipitation of oxalic acid with a solution obtained by dissolving a rare earth element of Y, Gd, Ce, and Sm in an acid at a stoichiometric ratio, and aluminum oxide and gallium oxide. Mix to obtain a mixed raw material. An appropriate amount of fluoride such as ammonium fluoride is mixed with this as a flux and packed in a crucible and fired in air at a temperature range of 1350 to 1450 ° C. for 2 to 5 hours to obtain a fired product. Next, the fired product is ball milled in water, washed, separated and dried, and finally passed through a sieve to obtain a desired phosphor.

Furthermore, when obtaining a cerium-doped YAG phosphor that emits yellow light when excited by blue light, appropriate amounts of Y ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , and Al ₂ O ₃ are prepared as raw materials. Then, a raw material mixture in which these are sufficiently mixed is filled in an aluminum crucible, and an appropriate amount of fluoride such as ammonium fluoride is mixed therein as a flux, and 1350 to 1450 in a reducing atmosphere while flowing hydrogen-containing nitrogen gas. Firing is performed for 2 to 5 hours in a temperature range of ° C to obtain a fired product. The obtained baked product is pulverized, washed, separated, and dried to obtain a desired phosphor. Further, the composition of the obtained phosphor was examined to confirm that it was a desired phosphor, and the emission wavelength in the excitation light of 465 nm was examined. As a result, it was confirmed that the peak wavelength was approximately 570 nm. That is, it was possible to obtain a phosphor that emits yellow light when irradiated with blue light.

  Further, the content of this phosphor is preferably about 0.02 to 12%, more preferably about 0.05 to 5% in volume ratio. If the phosphor content is less than 0.02%, the amount of fluorescent light is too small, and if it exceeds 12%, the phosphor itself shields the light. Thus, if the content of the phosphor is about 0.02 to 12%, the amount of light to be converted is not too low, and the amount of light that does not hinder the light transmission can be obtained. Thus, a phosphor-dispersed glass capable of emitting the mixed color light can be produced.

  Further, if the content is more preferably about 0.05 to 5%, the amount of light to be converted is further improved, and the light transmission is further improved. A body-dispersed glass can be produced.

  The glass powder 1 preferably has a maximum particle size of 160 μm or more and a median diameter d50 of 5 μm or more. The median diameter d50 is the particle diameter (cumulative average diameter) at which the cumulative curve becomes 50% when the cumulative curve is obtained with the total volume of one group of particles as 100%, and the maximum particle diameter is This is the particle size at which the cumulative curve becomes 100%. These parameters are generally used as one of parameters for evaluating the particle size distribution. The median diameter d50 and the maximum particle diameter can be measured using a general laser diffraction / scattering particle size measuring apparatus. Specifically, HELOS (manufactured by JEOL), Microtrac HRA (manufactured by Nikkiso) And SALD series (manufactured by Shimadzu Corporation). Particularly preferred is the SALD series (manufactured by Shimadzu Corporation).

  As described above, the median diameter d50 means a diameter in which the large side and the small side are equivalent when the powder is divided into two from a certain particle diameter. During the heat and pressure molding, bubbles are more easily removed when the maximum particle size is 160 μm or more. If the maximum particle size is less than 160 μm, bubbles are difficult to escape. Moreover, when the median diameter d50 (average particle diameter) is less than 5 μm, when powder is put into a mold, dust rises and handling becomes difficult. In addition, the work environment may be harmed. Further, the upper limit of the maximum particle diameter may be in a range where good scattered light can be obtained, and can be appropriately determined according to the combination of the LED light emitting element and the phosphor.

  As described above, by setting the particle diameter of the glass powder 1 to a predetermined size, it is possible to disperse the phosphor with a predetermined density to such an extent that a good scatterer can be formed. Therefore, the primary light emitted from the LED light-emitting element can be satisfactorily scattered and the generation of bubbles that white emulsify the glass can be suppressed, and the primary light and the secondary light emitted from the phosphor can be mixed well. A phosphor-dispersed glass capable of emitting light with uniform color mixing light (third light) can be manufactured.

  Further, it is preferable that the glass powder 1 has no crystal precipitation at the time of heating in the heat and pressure molding step S2, or does not precipitate in a large amount even if it is slightly precipitated. Therefore, a glass whose crystal precipitation temperature is higher than the heating temperature is preferable, and when the heating temperature is 150 ° C. to 200 ° C. higher than the glass yield point, the crystal precipitation temperature is 200 ° C. or higher than the glass yield point. Is preferred. For example, P2O5-BaO-based glass, P2O5-ZnO-based glass, P2O5-Nb2O5-based, P2O5-B2O3-based glass, SiO2-based glass, B2O3-ZnO-La2O3-based glass, SiO2-B2O3-ZnO-based glass, or the like may be used. it can.

  Next, an example of the phosphor-dispersed glass manufactured by the phosphor-dispersed glass manufacturing method according to the present embodiment will be described with reference to FIG. The phosphor-dispersed glass 20 is a plate-like glass formed by adding a predetermined phosphor 2A to a transparent glass body 1A.

  Further, as will be described later, in the heating and pressing molding process of the present embodiment, if the amount of bubbles 4 is small, it may remain inside the glass.

  In the phosphor-dispersed glass 20, the primary light R1 emitted from the LED light emitting element 5 is converted into the secondary light R2 by the phosphor 2A added therein, and the primary light R1 and the secondary light R2 are mixed. It has a function of emitting light with three light R3.

  In addition, if the bubbles 4 remaining inside have an appropriate size and an appropriate density, the function of promoting light scattering is exhibited. May be. For example, the bubble 4 having a function to scatter the primary light R1 and the secondary light R2 is left, and the primary light R1 and the secondary light R2 are uniformly mixed to have a uniform color tone over a wide range. It becomes possible to emit mixed color light.

  However, if there are too many bubbles 4, there is a risk that the transmitted light is reduced and the glass is white emulsified. Therefore, it is important to limit the size and density of the bubbles 4 to a predetermined desired range. Moreover, it is preferable that the number obtained by multiplying the bubble diameter and the surface density is within a predetermined range. The size and density of the bubbles can be measured using, for example, a field emission scanning electron microscope (SU8000: manufactured by Hitachi High-Technologies Corporation).

  Next, examples in which the phosphor-dispersed glass 20 was actually manufactured will be described. As described above, the manufacturing method of the phosphor-dispersed glass employed here is the mixing step S1 in which the glass powder 1 having a predetermined particle diameter and the predetermined amount of the phosphor powder 2 are mixed, and the mixed material prepared in the mixing step. And heating and pressing molding step S2 for obtaining phosphor-dispersed glass by heating and pressing 10.

  First, general glass raw materials such as phosphate raw materials, oxide raw materials, carbonates, nitrates and the like are thoroughly mixed and prepared in powder, and prepared raw materials having the glass composition shown in Table 1 are prepared. Samples A, B, and C were used.

(Table 1)

  The prepared raw materials having the compositions shown in Table 1 were melted and vitrified in a melting furnace heated to 1100 to 1300 ° C., and then poured into water to obtain a rough snow-like cullet. This cullet was classified by passing 1680 μm through a standard sieve to prepare a glass powder sample having a maximum particle diameter of 600 μm and a median diameter of 460 μm. This was also designated as Powder I.

Further, for sample A, a glass powder sample having a maximum particle diameter of 350 μm and a median diameter of 240 μm is prepared, and this is used as powder II. Further, the maximum particle diameter is 250 μm and the median diameter is 150 μm.
A glass powder sample was prepared, and this was designated as powder III. Further, for samples A and B, a glass powder sample having a maximum particle diameter of 170 μm and a median diameter of 30 μm was prepared, and this was designated as powder IV.

Next, phosphor powder (using cerium-added YAG phosphor) was added to these powders I to IV at a predetermined ratio (0.8% to 3.2%) and mixed to obtain a mixed powder.

  This mixed powder is put into a mold having a predetermined shape, heated at a temperature within the range of the yield point of each glass + 100 ° C to 200 ° C, and then pressurized to form a uniform scattering of 23 mm square and a thickness of 1.0 to 2.0 mm. A body (phosphor-dispersed glass) was produced.

  Tables 2 and 3 show the test results for evaluating the scattering characteristics of the phosphor-dispersed glass obtained in the above-described Examples. In this evaluation test, the blue light of the LED light-emitting element is irradiated from behind the obtained phosphor-dispersed glass, and the color tone of the transmitted light is visually evaluated.

(Table 2)

(Table 3)

As shown in Tables 2 and 3, a glass powder (glass powder I) having a maximum particle diameter of 600 μm and a median diameter of 460 μm, a glass powder having a maximum particle diameter of 350 μm and a median diameter of 240 μm (glass powder II), and a maximum particle A glass powder (glass powder III) having a diameter of 250 μm and a median diameter of 150 μm, and a glass powder (glass powder IV) having a maximum particle diameter of 170 μm and a median diameter of 30 μm, each having a volume% of 0.8 to 3.2% phosphor ( Each of the mixed powders to which the cerium-added YAG phosphor was added was put into a mold, heated at a temperature in the range of the yield point of each glass + 100 ° C. to 200 ° C., and pressure molded. In this example, the mold containing the mixed powder was placed in a high-temperature space having the target heating temperature as the environmental temperature and pressurized. The mixed powder put into the mold may be heated from room temperature, or the mixed powder may be put into a preheated mold. Pressurization of the mixed powder is possible from the time when a minute amount of water adhering to the mixed powder evaporates and exceeds about 150 ° C. In this example, the phosphor-dispersed glass was produced by a single pressurization, but it may be applied in a plurality of times or may be gradually applied. When the obtained phosphor-dispersed glass was irradiated with blue light from the LED light emitting device from behind and the transmitted light was observed, a uniform white color tone was obtained.

  Glass A has a glass yield point of 497 ° C. and a heating temperature of 650 ° C., so that the heating temperature is 153 ° C. higher than the glass yield point. Therefore, by using a glass having a glass crystal precipitation temperature of 200 ° C. or higher than the glass yield point, crystal precipitation does not occur during heating, and the light transmittance does not decrease.

  Further, since the glass B has a glass yield point of 556 ° C. and a heating temperature of 700 ° C., the heating temperature is 144 ° C. higher than the glass yield point. Therefore, by using a glass having a glass crystal precipitation temperature of 200 ° C. or higher than the glass yield point, crystal precipitation does not occur during heating, and the light transmittance does not decrease.

  In addition, since the glass C has a yield point of 613 ° C. and a heating temperature of 800 ° C., the heating temperature is 187 ° C. higher than the yield point of the glass. Therefore, by using a glass having a glass crystal precipitation temperature of 200 ° C. or higher than the glass yield point, crystal precipitation does not occur during heating, and the light transmittance does not decrease.

  The yield point was measured using a thermomechanical analyzer (TMA / SS6000: manufactured by Seiko Instruments Inc.) under a temperature rising condition of 10 ° C. per minute.

  Bubbles may remain during the heat and pressure molding process. Generally, it is preferable to perform this heating and pressing until the bubbles disappear. However, in particular, when glass particles having a small particle diameter are used, the generated bubbles increase, and some bubbles may remain. However, if the remaining bubbles are small, it has the function of scattering the primary light emitted from the LED light emitting element and the function of scattering the secondary light emitted from the phosphor, and these primary light and secondary light overlap. It was found that the mixed color light was emitted well.

  Further, it was found that white emulsification of glass that hinders light transmission can be suppressed by limiting the size and number of bubbles to remain within a predetermined range with a predetermined diameter.

  Thus, even if bubbles remain during the heat and pressure molding process, if the bubbles have a predetermined size and density, the primary light emitted from the LED light emitting element and the secondary light emitted from the phosphor inside the glass. Can be mixed well. For this reason, when bubbles remain appropriately, a light emitting diode light source capable of emitting light of a desired color can be obtained without causing color shift and uniform color tone of mixed color light.

  Moreover, the type | mold used in a heat-pressure molding process can use the type | mold which consists of a normal metal mold | die conventionally used, ceramics, and another refractory. Thus, the phosphor-dispersed glass 20 having a desired shape can be manufactured using a mold having a predetermined shape. For example, by using a mold having a predetermined shape, a flat plate-like or disc-like phosphor-dispersed glass 20A shown in FIG. 4A, a convex lens-like phosphor-dispersed glass 20B shown in FIG. A convex-plate-shaped phosphor-dispersed glass 20C or the like in which the plate-shaped one shown in 4 (c) is convex can be manufactured.

  The phosphor-dispersed glass 20 (20A to 20C) thus manufactured converts the primary light emitted from the LED light-emitting element into secondary light, and the primary light and the secondary light are mixed in a uniform color. Emits third color light. For example, when the LED light-emitting element is a blue light-emitting element and the phosphor is a yellow phosphor, a phosphor-dispersed glass that emits white light with a uniform color tone without color shift can be obtained.

  As described above, according to the method for producing a phosphor-dispersed glass according to the present invention, a mixing step of mixing a glass powder having a predetermined particle diameter and a predetermined amount of phosphor powder, heating the mixture, and pressurizing the mixture. In this way, the phosphor-dispersed glass is produced with a heating and pressing molding process for molding into a predetermined shape, so that phosphor powder is formed at a predetermined density to the extent that a good scatterer can be formed without using a resin binder. The primary light emitted from the LED light emitting element is scattered well, and the primary light and the secondary light emitted from the phosphor are mixed well to make the emission color tone uniform, resulting in a color shift. In addition, a phosphor-dispersed glass that can emit light having a desired color can be manufactured.

  In addition, in the heat and pressure molding process, by leaving bubbles of a predetermined size and a predetermined density, white emulsification of the glass that hinders the transmission of light is suppressed, and primary light and phosphors emitted from the LED light emitting element are emitted. It becomes possible to produce a phosphor-dispersed glass that can scatter secondary light and can obtain mixed color light with a uniform color tone.

  The method for producing a phosphor-dispersed glass according to the present invention is suitably applied to a light-emitting diode light source that emits primary light emitted from an LED light-emitting element and secondary light emitted from a phosphor to emit light with a desired color of third light. It becomes the manufacturing method of possible fluorescent substance dispersion | distribution glass.

DESCRIPTION OF SYMBOLS 1 Glass powder 2 Phosphor powder 4 Bubble 5 LED light emitting element 10 Mixed powder 15 Preliminary molded body 20 Phosphor dispersion glass S1 Mixing process S2 Heating and pressing molding process

Claims (5)

Predetermined phosphor is dispersed, the fluorescence which said phosphor primary light for emitting the light - emitting element is converted into another color of the secondary light to produce a third light mixing the primary light and the secondary light A method for producing body-dispersed glass, comprising:
A mixing step of mixing a predetermined amount of glass powder having a maximum particle size of 160 μm or more and a median diameter d50 of 5 μm or more and a predetermined amount of phosphor powder, and heating and pressurizing the mixture into a predetermined shape A method for producing a phosphor-dispersed glass, comprising: a heat and pressure molding step of molding. The method for producing a phosphor-dispersed glass according to claim 1, wherein the amount of the phosphor powder is 0.02 to 12% by volume. The method for producing a phosphor-dispersed glass according to claim 2, wherein the amount of the phosphor powder is 0.05 to 5% by volume. The method for producing a phosphor-dispersed glass according to any one of claims 1 to 3, wherein the phosphor is an oxide phosphor that is stable at a heating temperature at which the glass is heated and pressed. Before Symbol Luminous element blue light emitting device, the phosphor is a yellow phosphor, the phosphor dispersed glass according to claim 1, wherein 4 of said third light is white Manufacturing method.

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