JP6830751B2 - Wavelength conversion member and light emitting device - Google Patents

Description

The present invention is a raw material for a wavelength conversion member used for producing a wavelength conversion member that converts the wavelength of light emitted by a light emitting diode (LED: Light Emitting Diode), a laser diode (LD: Laser Diode), or the like into another wavelength. Regarding powder.

In recent years, white LEDs have been increasingly applied to lighting applications as next-generation light sources to replace incandescent lamps and fluorescent lamps. As an example of such a next-generation light source, for example, in Patent Document 1, a light source in which a wavelength conversion member that absorbs a part of the light from the LED and converts it into yellow light is arranged on an LED that emits blue light. Is disclosed. This light source emits white light, which is a composite light of blue light emitted from an LED and yellow light emitted from a wavelength conversion member.

Conventionally, as the wavelength conversion member, a member in which a phosphor is dispersed in a resin matrix has been used. However, when the wavelength conversion member is used, there is a problem that the resin matrix is deteriorated by the light from the LED and the brightness of the light source tends to be lowered. Specifically, there is a problem that the resin matrix is deteriorated by the heat generated by the LED or high-energy short-wavelength (blue to ultraviolet) light, causing discoloration or deformation.

In order to solve the above problem, Patent Document 2 describes a glass matrix by sintering a material containing a lead-free glass powder having a softening point of 500 ° C. or higher and a phosphor at a temperature near the bending point of glass. A wavelength conversion member in which a phosphor is dispersed therein has been proposed. Since the wavelength conversion member is dispersed in a glass matrix which is an inorganic material, the wavelength conversion member has an advantage that it is chemically stable and has little deterioration, and that discoloration of the member due to excitation light is unlikely to occur. However, some phosphors have low heat resistance, and when they are sintered together with lead-free glass powder having a softening point of 500 ° C. or higher, the phosphor is thermally deteriorated and the luminous efficiency is lowered. There is.

Therefore, in order to suppress thermal deterioration of the phosphor, a method of dispersing the phosphor in a glass matrix having a glass transition point of less than 500 ° C. has been proposed (see, for example, Patent Document 3).

Japanese Unexamined Patent Publication No. 2000-208815 Japanese Unexamined Patent Publication No. 2003-258308 Japanese Unexamined Patent Publication No. 2012-158494

Since the wavelength conversion member described in Patent Document 3 also has a high sintering temperature of 500 ° C. or higher, the phosphor having low heat resistance deteriorates during sintering, or reacts with glass during sintering to form glass. The problem of causing discoloration is likely to occur. Further, since the weather resistance of the glass matrix is low, there is also a problem that the surface of the wavelength conversion member is deteriorated during use, the light transmittance is lowered, and the luminous efficiency is significantly lowered, particularly in an environment with high humidity.

In view of the above, the present invention provides a wavelength conversion member which is less likely to deteriorate during sintering even with a phosphor having low heat resistance, is also excellent in weather resistance, and is less likely to deteriorate due to aging even when used for a long period of time. It is an object of the present invention to provide a raw material powder for a wavelength conversion member capable of producing the same.

The present invention includes a glass powder containing P ⁵⁺ 0.1% or more in% cation, and F ⁻ + Cl ⁻ 0.1 to 70% in% Sn 2 ⁺ 1% and% anion, and a phosphor. The present invention relates to a raw material powder for a wavelength conversion member.

Since the glass powder used in the raw material powder for the wavelength conversion member of the present invention contains a predetermined amount of Sn ²⁺ in the glass composition, it is excellent in weather resistance and chemical durability, and further constitutes glass. Since F ⁻ and Cl ⁻ are contained in the above-mentioned predetermined ranges as anions, the glass has a low yield point. Therefore, the raw material powder for a wavelength conversion member of the present invention can obtain a wavelength conversion member whose phosphor is less likely to deteriorate during sintering, has excellent weather resistance, and is less likely to deteriorate due to aging even when used for a long period of time. Is possible.

In the raw material powder for a wavelength conversion member of the present invention, it is preferable that the glass powder contains P ⁵⁺ + Sn ²⁺ 70.5% or more in% of cation. According to this configuration, it is possible to improve the devitrification resistance and mechanical strength of the glass powder.

In the raw material powder for a wavelength conversion member of the present invention, the glass powder preferably contains Sn ²⁺ 10 to 90% and P ⁵⁺ 10 to 70% in% of cation.

In the raw material powder for a wavelength conversion member of the present invention, it is preferable that the glass powder does not contain In ³⁺ . Since In ³⁺ has a strong tendency to devitrify, devitrification is unlikely to occur during glass molding because it does not contain In ³⁺ .

In the raw material powder for a wavelength conversion member of the present invention, it is preferable that the glass powder does not contain Pb ²⁺ and As ³⁺ . Since Pb ²⁺ and As ³⁺ are environmentally hazardous substances, by not containing these components, the glass powder is environmentally preferable.

In the raw material powder for a wavelength conversion member of the present invention, it is preferable that the glass powder contains 0 to 50% of B ³⁺ + Zn ²⁺ + Si ⁴⁺ + Al ³⁺ in% cation. With this configuration, it becomes easy to obtain a glass powder having excellent weather resistance and chemical durability.

In the raw material powder for a wavelength conversion member of the present invention, it is preferable that the glass powder contains 0 to 10% of Mg ²⁺ + Ca ²⁺ + Sr ²⁺ + Ba ²⁺ in% cation. This makes it easier to obtain glass powder with excellent weather resistance and chemical durability.

In the raw material powder for a wavelength conversion member of the present invention, the refractive index of the glass powder is preferably 1.6 or more. According to this configuration, the efficiency of extracting light from the wavelength conversion member is likely to be improved. Further, by reducing the difference in refractive index between the glass powder and the phosphor, the light scattering loss at the interface between the two is reduced, and the emission intensity can be expected to be improved.

In the raw material powder for a wavelength conversion member of the present invention, the yield point of the glass powder is preferably 300 ° C. or lower. According to this configuration, the phosphor is less likely to deteriorate during sintering of the raw material powder for the wavelength conversion member.

In the raw material powder for a wavelength conversion member of the present invention, it is preferable that the water resistance of the glass powder based on JOBIS is grade 3 or higher. According to this configuration, it is possible to obtain a wavelength conversion member that does not easily deteriorate due to aging even when used for a long period of time.

In the raw material powder for a wavelength conversion member of the present invention, the degree of coloration λ ₇₀ of the glass powder is preferably less than 500 nm. According to this configuration, since the wavelength conversion member has excellent light transmittance in the visible region or the near-ultraviolet region, it is possible to improve the light emission intensity.

In the raw material powder for a wavelength conversion member of the present invention, the phosphors are nitride phosphors, oxynitride phosphors, oxide phosphors, sulfide phosphors, acid sulfide phosphors, halide phosphors, and aluminates. It is preferably one or more selected from a fluorescent substance and a quantum dot phosphor.

The wavelength conversion member of the present invention is characterized by being made of a sintered body of the above-mentioned raw material powder for a wavelength conversion member.

The wavelength conversion member of the present invention is a phosphor in a glass matrix containing P ⁵⁺ 0.1% or more in% cation, and F ⁻ + Cl ⁻ 0.1 to 70% in Sn 2 ⁺ 1% or more and% anion. Is characterized by being dispersed.

The light emitting device of the present invention is characterized by including the above-mentioned wavelength conversion member and a light source for irradiating the wavelength conversion member with excitation light of a phosphor.

According to the present invention, it is possible to obtain a wavelength conversion member that does not easily deteriorate during sintering even with a phosphor having low heat resistance, has excellent weather resistance, and does not easily deteriorate due to aging even when used for a long period of time. It is possible to provide a raw material powder for a wavelength conversion member.

It is a schematic side view which shows one Embodiment of the light emitting device of this invention.

The raw material powder for a wavelength conversion member of the present invention is characterized by containing a glass powder and a phosphor. The glass powder contains P ⁵⁺ 0.1% or more in terms of cation% and Sn 2 ⁺ 1% or more and F ⁻ + Cl ⁻ 0.1 to 70% in anion%. The reason for limiting the content of each component in the glass powder in this way will be described below. Unless otherwise specified, "%" means "cation%" or "anion%" in the following description of the content of each component.

P ⁵⁺ is a component of the glass skeleton. In addition, it has the effect of increasing the light transmittance, and is particularly effective in suppressing the decrease in the light transmittance in the vicinity of the ultraviolet region. In particular, in the case of glass having a high refractive index, the effect of improving the light transmittance by P ⁵⁺ can be easily obtained. It also has the effect of suppressing devitrification and the effect of lowering the yield point. The content of P ⁵⁺ is 0.1% or more, preferably 1% or more, more preferably 5% or more, further preferably 10% or more, and preferably 20% or more. Especially preferable. If the content of P ⁵⁺ is too small, it becomes difficult to obtain the above effect. On the other hand, if the content of P ⁵⁺ is too large, the content of Sn ²⁺ is relatively small, and the refractive index tends to decrease and the weather resistance tends to decrease. Therefore, the content of P ⁵⁺ is preferably 70% or less, more preferably 65% or less, further preferably 60% or less, particularly preferably 55% or less, and 50% or less. Is most preferable.

Sn ²⁺ is an essential component for achieving high refractive index optical properties and improving chemical durability and weather resistance. It also has the effect of lowering the yield point. The Sn ²⁺ content is 1% or more, preferably 5% or more, more preferably 10% or more, further preferably 15% or more, and particularly preferably 20% or more. , 25% or more is most preferable. If the content of Sn ²⁺ is too small, it becomes difficult to obtain the above effect. On the other hand, if the Sn ²⁺ content is too high, it becomes difficult to vitrify and the devitrification resistance tends to decrease. Therefore, the Sn ²⁺ content is preferably 90% or less, more preferably 87.5% or less, further preferably 85% or less, and particularly preferably 82.5% or less. ..

The content of P ⁵⁺ + Sn ²⁺ is preferably 50% or more, more preferably 70.5% or more, further preferably 75% or more, particularly preferably 80% or more, 85. % Or more is most preferable. If the content of P ⁵⁺ + Sn ²⁺ is too small, the devitrification resistance and mechanical strength tend to decrease. The upper limit is not particularly limited, and the content of P ⁵⁺ + Sn ²⁺ may be 100%, but when it contains other components, it is preferably 99.9% or less, and 99% or less. It is more preferably 95% or less, and particularly preferably 90% or less.

The glass powder can further contain the following components as cation components.

B ³⁺ , Zn ²⁺ , Si ⁴⁺ and Al ³⁺ are constituents of the glass skeleton, and are particularly effective in improving chemical durability. The content of B ³⁺ + Zn ²⁺ + Si ⁴⁺ + Al ³⁺ is preferably 0 to 50%, more preferably 0 to 30%, further preferably 0.1 to 25%, and 0.5 to 25%. It is particularly preferably 20%, most preferably 0.75 to 15%. If the content of B ³⁺ + Zn ²⁺ + Si ⁴⁺ + Al ³⁺ is too large, the devitrification resistance tends to decrease. Further, as the melting temperature rises, Sn metal and the like are precipitated, and the light transmittance tends to decrease. In addition, the yield point tends to rise. Further, it becomes difficult to obtain high-refractive glass. From the viewpoint of improving weather resistance, it is preferable to contain B ³⁺ + Zn ²⁺ + Si ⁴⁺ + Al ³⁺ in an amount of 0.1% or more.

The preferable content range of each component is as follows.

B ³⁺ is a component constituting the glass skeleton. In addition, it has the effect of improving weather resistance, and in particular, it has a great effect of suppressing the selective elution of components such as ^{P5 + in} the glass into water. The content of B ³⁺ is preferably 0 to 50%, more preferably 0.1 to 45%, and even more preferably 0.5 to 40%. If the content of B ³⁺ is too large, the refractive index and devitrification resistance tend to decrease. In addition, the light transmittance tends to decrease.

Zn ²⁺ is a component that acts as a flux. In addition, it has the effects of improving weather resistance, suppressing elution of glass components into various cleaning solutions such as polishing cleaning water, and suppressing deterioration of the glass surface in a high temperature and high humidity state. In addition, Zn ²⁺ also has the effect of stabilizing vitrification. In view of the above, the content of Zn ²⁺ is preferably 0 to 40%, more preferably 0.1 to 30%, and even more preferably 0.2 to 20%. If the content of Zn ²⁺ is too large, the light transmittance is lowered and the light is easily devitrified.

Si ^{4+ is} also a component constituting the glass skeleton. In addition, it has the effect of improving weather resistance, and in particular, it has a great effect of suppressing the selective elution of components such as ^{P5 + in} the glass into water. The content of Si ⁴⁺ is preferably 0 to 20%, more preferably 0.1 to 15%. If the content of Si ⁴⁺ is too large, the refractive index tends to decrease and the yield point tends to increase. In addition, veins and bubbles due to undissolution tend to remain in the glass.

Al ³⁺ is a component capable of forming a glass skeleton together with Si ⁴⁺ and B ³⁺ . In addition, it has the effect of improving weather resistance, and in particular, it has a great effect of suppressing the selective elution of components such as ^{P5 + in} the glass into water. The content of Al ³⁺ is preferably 0 to 20%, more preferably 0.1 to 15%. If the content of Al ³⁺ is too large, devitrification is likely to occur. In addition, the light transmittance tends to decrease. Further, the melting temperature becomes high, and the veins and bubbles due to undissolution tend to remain in the glass.

Mg ²⁺ , Ca ²⁺ , Sr ²⁺ and Ba ²⁺ (alkaline earth metal ions) are components that act as fluxes. In addition, it has the effects of improving weather resistance, suppressing elution of glass components into various cleaning solutions such as polishing cleaning water, and suppressing deterioration of the glass surface in a high temperature and high humidity state. It is also a component that increases the hardness of glass. However, if the content of these components is too large, the liquidus temperature rises (the liquidus viscosity decreases), and devitrified substances tend to precipitate during the melting or molding process. As a result, it becomes difficult to mass-produce. It should be noted that these components are characterized in that the refractive index does not fluctuate significantly. In view of the above, the content of Mg ²⁺ + Ca ²⁺ + Sr ²⁺ + Ba ²⁺ is preferably 0 to 10%, more preferably 0 to 7.5%, and further preferably 0.1 to 5%. It is preferably 0.2 to 1.5%, and particularly preferably 0.2 to 1.5%.

Li ⁺ is a component having the greatest effect of lowering the softening point among alkali metal oxides. Further, the refractive index can be improved by substituting with B ³⁺ , Si ⁴⁺ or Al ³⁺ . However, since Li ⁺ has a strong phase separation property, if its content is too large, the liquidus temperature rises and devitrified substances are likely to precipitate, which may reduce workability. In addition, Li ⁺ tends to reduce chemical durability and light transmittance. Furthermore, when Li ⁺ elutes from the glass powder, the emission of the phosphor may be significantly reduced. Therefore, the Li ⁺ content is preferably 0 to 10%, more preferably 0 to 5%, still more preferably 0 to 1%, and particularly preferably 0 to 0.1%.

Na ⁺ has the same effect of lowering the softening point as Li ⁺ . Further, the refractive index can be improved by substituting with B ³⁺ , Si ⁴⁺ or Al ³⁺ . However, if the content is too high, the refractive index tends to be significantly reduced or the generation of veins tends to be promoted. In addition, the liquidus temperature rises, and devitrified substances are likely to precipitate in the glass. In addition, Li ⁺ tends to reduce chemical durability and light transmittance. Furthermore, when Na ⁺ elutes from the glass powder, the emission of the phosphor may be significantly reduced. Therefore, the Na ⁺ content is preferably 0 to 10%, more preferably 0 to 5%, still more preferably 0 to 1%, and particularly preferably 0 to 0.1%.

Like Li ⁺ , K ⁺ also has the effect of lowering the softening point. Further, the refractive index can be improved by substituting with B ³⁺ , Si ⁴⁺ or Al ³⁺ . However, if the content is too large, the refractive index tends to be significantly lowered and the weather resistance tends to be lowered. In addition, the liquidus temperature rises, and devitrified substances are likely to precipitate in the glass. Furthermore, when K ⁺ elutes from the glass powder, the emission of the phosphor may be significantly reduced. It should be noted that K ⁺ tends to reduce the chemical durability and the light transmittance. Accordingly, the content of _{K 2} O is preferably 0 to 10%, more preferably 0-5%, more preferably 0 to 1%, particularly preferably 0 to 0.1%.

The content of Li ⁺ + Na ⁺ + K ⁺ is preferably 0 to 10%, more preferably 0 to 5%, further preferably 0 to 1%, and 0 to 0.1%. Is particularly preferable. If the content of Li ⁺ + Na ⁺ + K ⁺ is too large, devitrification tends to occur and the chemical durability tends to decrease. In addition, it becomes difficult to obtain desired optical characteristics.

Cs ⁺ may be contained as an alkali metal component. Cs ⁺ has the effect of lowering the softening point. However, if the content is too large, the refractive index tends to be significantly lowered and the weather resistance tends to be lowered. In addition, the liquidus temperature rises and devitrified substances are likely to precipitate. Therefore, the content of Cs ⁺ is preferably 0 to 1%, more preferably 0 to 0.5%, and more preferably not contained.

La ³⁺ and Gd ³⁺ are components that improve the refractive index with almost no decrease in light transmittance. However, if the content is too large, the devitrification resistance tends to decrease. Therefore, the content of these components is preferably 0 to 10%, more preferably 0.1 to 7.5%, and even more preferably 1 to 5%, respectively.

Ta ⁵⁺ , W ⁶⁺ and Nb ⁵⁺ have the effect of increasing the refractive index with almost no decrease in light transmittance. However, if the content is too large, the devitrification resistance tends to decrease. Therefore, the content of these components is preferably 0 to 10%, more preferably 0.1 to 7.5%, and even more preferably 1 to 5%, respectively.

Ti ⁴⁺ is a component that has the effect of increasing the refractive index. Further, it is an effective component for improving devitrification resistance as compared with Nb ⁵⁺ and W ⁶⁺ . However, if the content is too large, the light transmittance tends to decrease. In particular, when the glass contains a large amount of Fe component as an impurity (for example, 20 ppm or more), the light transmittance tends to decrease remarkably. In addition, the devitrification resistance tends to decrease. Therefore, the content of Ti ⁴⁺ is preferably 0 to 10%, more preferably 0.1 to 7.5%, and even more preferably 1 to 5% or less.

Y ³⁺ , Yb ³⁺ and Ge ⁴⁺ have the effect of increasing the refractive index with almost no decrease in light transmittance. However, if the content is too large, the devitrification resistance tends to decrease. Therefore, the content of these components is preferably 0 to 10%, more preferably 0.1 to 7.5%, and even more preferably 1 to 5%, respectively.

Te ⁴⁺ and Bi ³⁺ are components that easily reduce the light transmittance, and are blackened and the light transmittance is significantly reduced, especially under melting conditions where the oxygen concentration is low. Therefore, the contents of Te ⁴⁺ and Bi ³⁺ are preferably 0 to 1%, and more preferably not contained.

Zr ⁴⁺ is a component for improving chemical durability and weather resistance and obtaining optical characteristics having a high refractive index. The content of Zr ⁴⁺ is preferably 0 to 5%, more preferably 0 to 4%, further preferably 0.1% to 3%, and 0.2 to 2%. Is particularly preferable. If the content of Zr ⁴⁺ is too large, the devitrification resistance tends to decrease, or the melting temperature rises and the light transmittance tends to decrease.

The content of La ³⁺ + Gd ³⁺ + Ta ⁵⁺ + W ⁶⁺ + Nb ⁵⁺ + Ti ⁴⁺ + Y ³⁺ + Yb ³⁺ + Ge ⁴⁺ is preferably 0 to 10%, more preferably 0.1 to 7.5%, and 0.2. It is more preferably ~ 5%, and most preferably 0.3 ~ 2.5%. If the content of La ³⁺ + Gd ³⁺ + Ta ⁵⁺ + W ⁶⁺ + Nb ⁵⁺ + Ti ⁴⁺ + Y ³⁺ + Yb ³⁺ + Ge ⁴⁺ is too large, the devitrification resistance tends to decrease or the melting temperature tends to increase and the light transmittance tends to decrease. Become. In order to obtain a glass having a high refractive index and excellent weather resistance, it is preferable to contain La ³⁺ + Gd ³⁺ + Ta ⁵⁺ + W ⁶⁺ + Nb ⁵⁺ + Ti ⁴⁺ + Y ³⁺ + Yb ³⁺ + Ge ⁴⁺ in an amount of 0.1% or more.

Fe ³⁺ , Ni ²⁺ and Co ²⁺ are components that reduce the light transmittance. Therefore, the content of each of these components is preferably 0.1% or less, and more preferably not contained.

In addition, rare earth components such as Ce ⁴⁺ , Pr ³⁺ , Nd ³⁺ , Eu ³⁺ , Tb ³⁺ and Er ³⁺ may also reduce the light transmittance, so the content of each of these components is less than 0.1%. It is preferable, and it is more preferable not to contain it.

Since In ³⁺ has a strong tendency to devitrify, it is preferable not to contain it.

For environmental reasons, it is preferable that Pb ²⁺ and As ³⁺ are not contained.

The glass powder in the present invention contains a halide ion F ⁻ or Cl ⁻ as an anion. F ⁻ and Cl ⁻ have the effect of lowering the yield point and the effect of increasing the light transmittance. However, if the content is too large, the volatility at the time of melting becomes high and the veins are likely to occur. In addition, it becomes easy to devitrify. Glass powder in the present invention, with ^anionic%, F ^- + Cl ^- containing ^0.1~70%, F ^- + Cl ^- to preferably contains ^{1~67.5%, F - + Cl -} 5~65% It is more preferable to contain F ⁻ + Cl ⁻ 2 to 30%, and it is particularly preferable to contain F ⁻ + Cl ⁻ 10 to 60%. In addition to SnF ₂ and SnCl ₂ , fluorides of La, Gd, Ta, W, Nb, Y, Yb, Ge, Mg, Ca, Sr or Ba can be used as raw materials for introducing F ⁻ and Cl ^−. And chlorides.

As the halide ion, Br ⁻ or the like may be contained in addition to the above components. Other than the halide ion, it usually contains an oxygen ion (O ^2- ).

The refractive index (nd) of the glass powder is preferably 1.6 or more, more preferably 1.65 or more, still more preferably 1.7 or more, and particularly preferably 1.72 or more. If the refractive index of the glass powder is too small, the efficiency of extracting light from the wavelength conversion member tends to decrease. In addition, the difference in refractive index between the glass powder and the phosphor becomes large, the light scattering loss at the interface between the two becomes large, and the emission intensity may decrease. The upper limit is not particularly limited, but if the refractive index is too high, the glass tends to become unstable, so the upper limit is preferably 1.95 or less, more preferably 1.9 or less.

The degree of coloration λ ₇₀ of the glass powder is preferably less than 500 nm, more preferably 470 nm or less, and further preferably 460 nm or less. If the degree of coloring λ ₇₀ is too large, the light transmittance in the near-ultraviolet region to the visible region tends to be inferior. As a result, the amount of excitation light irradiated to the phosphor is reduced, and it becomes difficult to obtain emitted light having a desired color from the wavelength conversion member.

The yield point of the glass powder is preferably 300 ° C. or lower, more preferably 280 ° C. or lower, further preferably 260 ° C. or lower, and particularly preferably 250 ° C. or lower. When the yield point of the glass powder satisfies the above range, sintering at a low temperature becomes possible, and deterioration of the phosphor can be suppressed.

In the powdered glass of the present invention, the difference between the softening temperature (TF) and the crystallization temperature (Tc) is preferably 30 ° C. or higher, more preferably 40 ° C. or higher, and further preferably 50 ° C. or higher. preferable. If the difference between the softening temperature (TF) and the crystallization temperature (Tc) is too small, crystals are likely to precipitate during sintering. As a result, the light transmittance is lowered and the sintering is insufficient, making it difficult to obtain a dense sintered body.

The coefficient of thermal expansion of the glass powder at 20 to 100 ° C. is preferably 80 × ^10-7 to 200 × ^10-7 / ° C., more preferably 100 × ^{10-7 to} 190 × ^10-7 / ° C. , 120 × 10 ^{-7 to} 180 × 10 ^-7 / ° C., more preferably. If the coefficient of thermal expansion is too low or too high, the coefficient of thermal expansion of the base material for fixing the wavelength conversion member and the adhesive material for adhering the wavelength conversion member and the base material will not match, and the temperature will be high. Cracks are likely to occur when used in.

The water resistance of the glass powder according to JOBIS is preferably grade 3 or higher. If the water resistance is out of the above range, the wavelength conversion member may become cloudy in a manufacturing process (for example, a cleaning process) and the light transmittance may decrease.

The glass powder can be produced as follows. First, the raw materials are prepared so as to have a desired composition, and then melted in a melting furnace. As the raw material, oxides, carbonates, nitrates, phosphates, halogen compounds (fluorides, chlorides, bromides, iodides, astatates) and the like can be used. Here, after the cullet is produced by the primary melting, the refractive index can be adjusted and the composition can be homogenized by performing the secondary melting using the cullet. By homogenizing the composition, glass having high light transmittance can be obtained. At the time of secondary melting, the refractive index can be precisely controlled by using a cullet having a high refractive index and a cullet having a low refractive index. The melting atmosphere is preferably an inert atmosphere or a reducing atmosphere. For example, by melting in an inert atmosphere such as nitrogen or argon, a homogeneous glass can be easily obtained. As the glass melting container, metals such as platinum and gold, refractories, quartz glass, glassy carbon and the like can be used. A gold container is particularly preferable because an alloy reaction with Sn ²⁺ is unlikely to occur. As the metal container, it is preferable to use a reinforcing material in which an oxide such as ZrO ₂ is dispersed.

Next, the molten glass is formed into a film, and a ball mill is used to obtain powdered glass.

The particle size of the glass powder is not particularly limited, but for example, the maximum particle size D ₉₉ is 200 μm or less (particularly 150 μm or less, further 105 μm or less), and the average particle size D ₅₀ is 0.1 μm or more (particularly 1 μm or more, further. Is preferably 2 μm or more). If the maximum particle size D ₉₉ of the glass powder is too large, the excitation light is less likely to be scattered in the wavelength conversion member, and the luminous efficiency is likely to decrease. Further, if the average particle diameter D ₅₀ is too small, the excitation light is excessively scattered in the wavelength conversion member, and the luminous efficiency tends to decrease.

In the present invention, the average particle diameter D ₅₀ and the maximum particle diameter D ₉₉ refer to the values measured by the laser diffraction method.

The phosphor is not particularly limited as long as it is generally available on the market. For example, nitride phosphors, oxynitride phosphors, oxide phosphors (including garnet-based phosphors such as YAG phosphors), sulfide phosphors, acid sulfide phosphors, halide phosphors (halophosphate formation). Fluorescent materials, etc.) and aluminate phosphors, etc. can be mentioned. These phosphors are usually on powder. Of these phosphors, nitride phosphors, oxynitride phosphors, and oxide phosphors are preferable because they have high heat resistance and are relatively resistant to deterioration during firing. The nitride phosphor and the oxynitride phosphor have a feature that the excitation light of near-ultraviolet to blue is converted into a wide wavelength region of green to red, and the emission intensity is relatively high. Therefore, the nitride phosphor and the oxynitride phosphor are particularly effective as phosphors used in wavelength conversion members for white LED elements.

The phosphor has an excitation band at a wavelength of 300 to 500 nm and an emission peak at a wavelength of 380 to 780 nm, particularly blue (wavelength 440 to 480 nm), green (wavelength 500 to 540 nm), and yellow (wavelength 540 to 595 nm). ) Or red (wavelength 600 to 700 nm).

Examples of phosphors that emit blue light when irradiated with ultraviolet to near-ultraviolet excitation light with a wavelength of 300 to 440 nm include (Sr, Ba) MgAl ₁₀ O ₁₇ : Eu ²⁺ , (Sr, Ba) ₃ MgSi ₂ O ₈ : Eu. ^{2+ and the} like can be mentioned.

Examples of phosphors that emit green fluorescence when irradiated with excitation light with a wavelength of 300 to 440 nm from ultraviolet to near ultraviolet are SrAl ₂ O ₄ : Eu ²⁺ , SrBaSiO ₄ : Eu ²⁺ , Y ₃ (Al, Gd) ₅ O ₁₂ : Ce ³⁺ , SrSiO _n : Eu ²⁺ , BaMgAl ₁₀ O ₁₇ : Eu ²⁺ , Mn ²⁺ , Ba ₂ MgSi ₂ O ₇ : Eu ²⁺ , Ba ₂ SiO ₄ : Eu ²⁺ , Ba ₂ Li ₂ Si ₂ O ₇ : Eu ²⁺ , BaAl ₂ O ₄ : Eu ^{2+ and the} like.

Examples of phosphors that emit green fluorescence when irradiated with blue excitation light having a wavelength of 440 to 480 nm include SrAl ₂ O ₄ : Eu ²⁺ , SrBaSiO ₄ : Eu ²⁺ , Y ₃ (Al, Gd) ₅ O ₁₂ : Ce ³⁺ , Examples thereof include SrSiOn: Eu ²⁺ and β-SiAlON: Eu ²⁺ .

Examples of the phosphor that emits yellow fluorescence when irradiated with ultraviolet-near-ultraviolet excitation light having a wavelength of 300 to 440 nm include La ₃ Si ₆ N ₁₁ : Ce ^{3+ and the} like.

Examples of the phosphor that emits yellow fluorescence when irradiated with blue excitation light having a wavelength of 440 to 480 nm include Y ₃ (Al, Gd) ₅ O ₁₂ : Ce ³⁺ and Sr ₂ SiO ₄ : Eu ²⁺ .

CaGa ₂ S ₄ : Mn ²⁺ , MgSr ₃ Si ₂ O ₈ : Eu ²⁺ , Mn ²⁺ , Ca ₂ MgSi ₂ are examples of phosphors that emit red fluorescence when irradiated with ultraviolet-near-ultraviolet excitation light with a wavelength of 300 to 440 nm. O ₇ : Eu ²⁺ , Mn ^{2+ and the} like can be mentioned.

Examples of phosphors that emit red fluorescence when irradiated with blue excitation light having a wavelength of 440 to 480 nm include CaAlSiN ₃ : Eu ²⁺ , CaSiN ₃ : Eu ²⁺ , (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , α-. SiAlON: Eu ^{2+ and the} like.

In addition to the above phosphor, a quantum dot phosphor can also be used. Specific examples of the quantum dot phosphor include CdSe, CdTe, ZnSe, CdS, PbSe, PbS, CIS, ZCIS, ZCIGS, CdSe / ZnS, ZnS / CdSe / ZnS, CdSe / ZnSe / ZnS, and the like. Quantum dot phosphors are usually handled in a state of being dispersed in an organic solvent.

A plurality of phosphors may be mixed and used according to the wavelength range of excitation light or emission. For example, when white light is obtained by irradiating excitation light in the ultraviolet region, phosphors that emit blue, green, yellow, and red fluorescence may be mixed and used.

If the content of the phosphor in the wavelength conversion member is too large, it tends to be difficult to sinter and the porosity tends to increase. As a result, in the obtained wavelength conversion member, problems such as difficulty in efficiently irradiating the phosphor with excitation light and a tendency to reduce the mechanical strength occur. On the other hand, if the content of the phosphor is too small, it becomes difficult to obtain a desired emission intensity. From this point of view, the content of the phosphor in the wavelength conversion member is mass%, preferably 0.01 to 50%, more preferably 0.05 to 40%, still more preferably 0.1 to 30%. Adjusted in range.

In addition, in the wavelength conversion member whose purpose is to reflect the fluorescence generated in the wavelength conversion member to the excitation light incident side and mainly extract only the fluorescence to the outside, the emission intensity is maximized, not limited to the above. As described above, the content of the phosphor can be increased (for example, 50% to 80% by mass, and further 55 to 75%).

The wavelength conversion member of the present invention is obtained by sintering the above-mentioned raw material powder for a wavelength conversion member. Specifically, the wavelength conversion member of the present invention is a glass containing P ⁵⁺ 0.1% or more in% cation, Sn 2 ⁺ 1% or more, and F ⁻ + Cl ⁻ 0.1 to 70% in% anion. It is characterized in that the phosphor is dispersed in the matrix. Here, since the characteristics of the glass matrix are the same as those of the glass powder described above and the characteristics of the phosphor are also as described above, the description thereof will be omitted.

The wavelength conversion member of the present invention may be formed by directly charging a phosphor during melting of glass having the above composition, uniformly dispersing it, and then molding it. Here, the temperature at which the phosphor is charged is preferably higher than the liquidus temperature of the glass and lower than the temperature at which the phosphor is deactivated. Further, the mixture of the glass powder and the phosphor may be sintered and the phosphor layer may be formed by applying the mixture of the glass powder and the phosphor on the base material and heating the mixture. Examples of the base material include a transparent substrate such as a glass plate, a ceramic substrate such as alumina, and a metal substrate such as Al, Pt, and Au. The phosphor may be dispersed on the surface of the base material, a glass plate having the above composition may be placed on the glass plate, and then heated to soften the glass plate to seal the phosphor. Alternatively, the phosphor is dispersed on the surface of a glass plate having the above composition, another glass plate having the above composition is placed on the surface, and then each glass plate is softened by heating to seal the phosphor. You may. After sandwiching the phosphor in a state of being dispersed between two glass plates having the above composition, the glass plate may be softened by heating to seal the phosphor.

The firing temperature of the raw material powder for the wavelength conversion member is preferably in the range of the softening point of the glass powder within ± 100 ° C., within ± 80 ° C., and further within ± 50 ° C. If the firing temperature is too low, the glass powder does not flow sufficiently and it is difficult to obtain a dense sintered body. On the other hand, if the firing temperature is too high, the emission intensity is lowered due to the elution of the phosphor in the glass powder, the diffusion of the components contained in the phosphor into the glass powder, and the coloring of the glass powder. There is a risk.

The atmosphere at the time of firing is preferably an atmospheric atmosphere or an inert atmosphere such as a vacuum, nitrogen atmosphere, or argon atmosphere. In particular, in an inert atmosphere, devitrification of the glass powder during firing can be suppressed. In addition, it is possible to suppress deterioration of the light emission characteristics of a fluorescent substance (quantum dot fluorescent substance, etc.) having relatively low heat resistance. As a result, it is possible to improve the emission intensity of the wavelength conversion member.

The shape of the wavelength conversion member of the present invention is not particularly limited, and for example, not only a member having a specific shape itself such as a plate shape, a columnar shape, a spherical shape, a hemispherical shape, a hemispherical shape, etc., but also a glass substrate, a ceramic substrate, etc. It may be in the form of a film formed on the surface of the base material of.

The light emitting device of the present invention is characterized by including the above-mentioned wavelength conversion member and a light source that irradiates the wavelength conversion member with excitation light of a phosphor. FIG. 1 is a schematic side view showing an embodiment of the light emitting device of the present invention. As shown in FIG. 1, the light emitting device 1 includes a wavelength conversion member 2 and a light source 3. Light source 3 irradiates the excitation light L _in the phosphor with respect to the wavelength conversion member 2. Excitation light L _in incident to the wavelength conversion member 2 is converted into light of another wavelength, the light source 3 emits as L _out from the opposite side. At this time, the combined light of the light after the wavelength conversion and the excitation light transmitted without the wavelength conversion may be emitted, or only the light after the wavelength conversion may be emitted.

Hereinafter, the present invention will be described in detail based on examples, but the present invention is not limited to these examples.

(1) Preparation of Glass Powder Tables 1 and 2 show the glass powder according to Examples (a to j) and Comparative Example (k) of the present invention, respectively.

First, the raw materials were prepared so as to have each glass composition shown in the table, and melted at 700 to 1000 ° C. for 1 hour using a gold crucible. The obtained molten glass was film-molded and pulverized with a ball mill to obtain a glass powder having an average particle size of 10 μm. At the same time, a part of the molten glass was cast into a carbon mold to form a size of 50 mm × 50 mm × 15 mm, and a sample for measurement was prepared.

The refractive index (nd), coefficient of thermal expansion, yield point, softening temperature, crystallization temperature, degree of coloring, acid resistance and water resistance of the obtained sample were measured. The results are shown in Tables 1 and 2.

The refractive index is shown as a measured value of the helium lamp with respect to the d line (587.6 nm).

The coefficient of thermal expansion and the yield point were measured using a thermal expansion measuring device (dirato meter). The coefficient of thermal expansion was measured in the temperature range of 20 to 100 ° C.

The softening temperature (TF) and the crystallization temperature (Tc) were measured by a differential thermal analyzer.

The degree of coloration was measured as follows. For an optically polished sample having a thickness of 10 mm ± 0.1 mm, the light transmittance in the wavelength range of 200 to 800 nm was measured at intervals of 0.5 nm using a spectrophotometer to prepare a light transmittance curve. In the light transmittance curve, the shortest wavelength showing a light transmittance of 70% was defined as the degree of coloring λ ₇₀ .

Acid resistance and water resistance were measured by the powder method specified in JOGIS.

(2) Preparation of Wavelength Conversion Member Tables 3 to 5 show the wavelength conversion member according to Examples (No. 1 to 10, 12 to 21, 23 to 32) and Comparative Example (No. 11, 22, 33). There is.

Each glass powder sample described in Table 1 and 2, the CaAlSiN ₃ or alpha-SiAlON to obtain mixed powder was mixed at a predetermined weight ratio shown in Table 3 and 4 as a phosphor. The mixed powder was pressure-molded with a mold to prepare a columnar premolded body having a diameter of 1 cm. Further, each of the glass powders shown in Tables 1 and 2 was pressure-molded with a mold to prepare a columnar green compact having a diameter of 1 cm, and a solvent in which the quantum dot phosphor PbS was dispersed as a phosphor was used at this pressure. The powder was dropped and impregnated to obtain a columnar premolded product. The mixing ratio of the glass powder and PbS was as shown in Table 5. Each of the obtained premolded bodies is fired at a temperature of softening temperature of glass powder + 30 ° C., and then the obtained sintered body is processed to form a disk-shaped wavelength conversion member having a diameter of 8 mm and a thickness of 0.2 mm. Got The emission spectrum of each of the obtained wavelength conversion members was measured, and the luminous efficiency was calculated. The results are shown in Tables 3-5.

Luminous efficiency was determined as follows. First, a wavelength conversion member was placed on a light source having an excitation wavelength of 460 nm, and the energy distribution spectrum of light emitted from the upper surface of the sample was measured in the integrating sphere. Next, the total luminous flux was calculated by multiplying the obtained spectrum by the standard luminosity function, and the total luminous flux was divided by the power of the light source to calculate the luminous efficiency.

As is clear from Tables 3 to 5, when CaAlSiN ₃ was used as the phosphor, No. 1 of Examples. The samples 1 to 10 had a luminous efficiency of 6.4 lm / W or more, whereas No. 1 was a comparative example. The luminous efficiency of 11 samples was as low as 5.0 lm / W.

When α-SiAlON was used as the phosphor, No. The samples of Nos. 12 to 21 had a luminous efficiency of 7.9 lm / W or more, whereas No. 12 to 21 was a comparative example. The luminous efficiency of 22 samples was as low as 6.5 m / W.

When the quantum dot phosphor PbS was used as the phosphor, No. The samples of 23 to 32 had a luminous efficiency of 4.9 lm / W or more, whereas No. 23 was a comparative example. The quantum dot phosphor of 33 samples deteriorated and did not emit light.

In addition, No. Since the wavelength conversion members 1 to 10, 12 to 21, and 23 to 32 are made by using a glass powder sample having excellent acid resistance and water resistance, the surface is less likely to deteriorate even after long-term use. , It is considered unlikely that the luminous efficiency will be significantly reduced.

The raw material powder for a wavelength conversion member of the present invention is suitable for producing a wavelength conversion member used for general lighting such as a single color or white LED, special lighting (for example, a projector light source, an in-vehicle headlamp light source), and the like.

1 Light emitting device 2 Wavelength conversion member 3 Light source

Claims (12)

^{Cationic%, P 5+ 35.4 ~ 49.1%} , and ^Sn 2+ 48.7 ~ 56.2%, containing ^P 5+ ^{+ Sn} 2+ 85% or more, ^anionic%, F - 0.4 ~ 49. A wavelength conversion member comprising a sintered body of a raw material powder for a wavelength conversion member containing a glass powder containing 6 % and a quantum dot phosphor. The wavelength conversion member according to claim 1, wherein the glass powder does not contain In ³⁺ . The wavelength conversion member according to claim 1 or 2 , wherein the glass powder does not contain Pb ²⁺ and As ³⁺ . The wavelength conversion member according to any one of claims 1 to 3 , wherein the glass powder contains 0 to 50% of B ³⁺ + Zn ²⁺ + Si ⁴⁺ + Al ³⁺ in% cation. The wavelength conversion member according to any one of claims 1 to 4 , wherein the glass powder contains 0 to 10% of Mg ²⁺ + Ca ²⁺ + Sr ²⁺ + Ba ²⁺ in% cation. The wavelength conversion member according to any one of claims 1 to 5 , wherein the glass powder has a refractive index of 1.6 or more. The wavelength conversion member according to any one of claims 1 to 6 , wherein the yield point of the glass powder is 300 ° C. or less. The wavelength conversion member according to any one of claims 1 to 7 , wherein the glass powder has a water resistance of grade 3 or higher based on JOBIS. The wavelength conversion member according to any one of claims 1 to 8 , wherein the degree of coloration λ _{70 of the} glass powder is less than 500 nm. ^{Cationic%, P 5+ 35.4 ~ 49.1%} , and ^Sn 2+ 48.7 ~ 56.2, and contains P ⁵⁺ + ^Sn 2+ 85% or more, ^anionic%, F - 0.4 ~ 49.6 A wavelength conversion member characterized in that quantum dot phosphors are dispersed in a glass matrix containing%. The wavelength conversion member according to any one of claims 1 to 9 , wherein the difference between the softening temperature and the crystallization temperature of the glass powder is 30 ° C. or more. A light emitting device comprising the wavelength conversion member according to any one of claims 1 to 11 and a light source for irradiating the wavelength conversion member with excitation light of the phosphor.