JP2019163208A - Raw material powder for wavelength conversion member - Google Patents

Abstract

To provide a raw material powder for a wavelength conversion member capable of obtaining a wavelength conversion member which is hardly deteriorated during sintering even in a case of a phosphor having low heat resistance, has excellent weather resistance and is hardly deteriorated due to change with time when used over a long period of time.SOLUTION: There is provided a raw material powder for a wavelength conversion member which contains a glass powder comprising, in cation percent, 0.1% or more of Pand 1% or more of Snand in anion percent, 0.1 to 70% of F+Cl, and a phosphor.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a material for a wavelength conversion member that is used to produce a wavelength conversion member that converts the wavelength of light emitted from a light emitting diode (LED) or a laser diode (LD) to another wavelength. Relates to powder.

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

  Conventionally, a wavelength conversion 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 luminance of the light source tends to be lowered. Specifically, there is a problem that the resin matrix deteriorates due to 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 discloses that a glass matrix is obtained 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 yield point of the glass. A wavelength conversion member in which a phosphor is dispersed has been proposed. Since the phosphor is dispersed in a glass matrix that is an inorganic material, the wavelength conversion member has an advantage that it is chemically stable and hardly deteriorated, and the member is not easily discolored by excitation light. However, some phosphors have low heat resistance, and if this is sintered together with a 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.

  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 (for example, see Patent Document 3).

JP 2000-208815 A JP 2003-258308 A JP 2012-158494 A

  Since the wavelength conversion member described in Patent Document 3 also has a sintering temperature as high as 500 ° C. or higher, the phosphor having low heat resistance deteriorates itself during sintering, or reacts with glass during sintering. The problem is likely to cause discoloration. Further, since the weather resistance of the glass matrix is low, the surface of the wavelength conversion member is altered during use, particularly in a high humidity environment, resulting in a problem that the light transmittance is lowered and the light emission efficiency is greatly lowered.

  In view of the above, the present invention provides a wavelength conversion member that is not easily deteriorated during sintering even with a phosphor having low heat resistance, is excellent in weather resistance, and is not easily deteriorated over time even when used over a long period of time. An object of the present invention is to provide a raw material powder for a wavelength conversion member that can be used.

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

Since the glass powder used for the raw material powder for wavelength conversion member of the present invention contains a predetermined amount of Sn ²⁺ in the glass composition, it has excellent weather resistance and chemical durability, and further constitutes glass. Since F ⁻ and Cl ⁻ are contained as anions in the predetermined range, the glass has a low yield point. Therefore, the raw material powder for wavelength conversion member of the present invention provides a wavelength conversion member that is less susceptible to deterioration of phosphors during sintering, is excellent in weather resistance, and is less likely to deteriorate over time even when used over a long period of time. Is possible.

In the raw material powder for wavelength conversion member of the present invention, the glass powder preferably contains cation% and contains P ⁵⁺ + Sn ²⁺ 70.5% or more. According to the said structure, it becomes possible to improve the devitrification resistance and mechanical strength of glass powder.

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

In the raw material powder for 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, it does not easily cause devitrification when glass is formed by not containing In ³⁺ .

In the raw material powder for 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, an environmentally preferable glass powder is obtained by not containing these components.

In the raw material powder for wavelength conversion member of the present invention, the glass powder preferably 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 wavelength conversion member of the present invention, the glass powder preferably contains 0 to 10% of Mg ²⁺ + Ca ²⁺ + Sr ²⁺ + Ba ²⁺ in cation%. Thereby, it becomes easy to obtain a glass powder excellent in weather resistance and chemical durability.

  In the raw material powder for wavelength conversion member of the present invention, the refractive index of the glass powder is preferably 1.6 or more. According to the said structure, the extraction efficiency of the light from a wavelength conversion member becomes easy to improve. In addition, by reducing the difference in refractive index between the glass powder and the phosphor, light scattering loss at the interface between the two can be reduced, and an improvement in emission intensity can be expected.

  In the raw material powder for wavelength conversion member of the present invention, the yield point of the glass powder is preferably 300 ° C. or lower. According to the said structure, a fluorescent substance becomes difficult to deteriorate at the time of sintering of the raw material powder for wavelength conversion members.

  In the raw material powder for wavelength conversion member of the present invention, the water resistance of the glass powder based on JOGIS is preferably tertiary or higher. According to this configuration, it is possible to obtain a wavelength conversion member that is not easily deteriorated due to changes over time even when used for a long period of time.

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

  In the raw material powder for wavelength conversion member of the present invention, the phosphor is nitride phosphor, oxynitride phosphor, oxide phosphor, sulfide phosphor, oxysulfide phosphor, halide phosphor, aluminate It is preferable that it is 1 or more types selected from fluorescent substance and quantum dot fluorescent substance.

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

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

  The light-emitting device of the present invention includes the above-described wavelength conversion member, and a light source that irradiates 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 is not easily deteriorated during sintering even with a phosphor having low heat resistance, is excellent in weather resistance, and is not easily deteriorated over time even when used over a long period of time. It becomes possible to provide a raw material powder for a wavelength conversion member.

It is a typical 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 cation%, P ⁵⁺ 0.1% or more, and Sn ²⁺ 1% or more, anion%, F ⁻ + Cl ⁻ 0.1 to 70%. Below, the reason which limited content of each component in glass powder in this way is demonstrated. Unless otherwise specified, in the following description regarding the content of each component, “%” means “cation%” or “anion%”.

P ⁵⁺ is a constituent component of the glass skeleton. Further, it has an effect of increasing the light transmittance, and particularly has a high effect of suppressing a decrease in light transmittance near the ultraviolet region. In particular, in the case of a glass having a high refractive index, the effect of improving the light transmittance due to P ⁵⁺ is easily obtained. It also has the effect of suppressing devitrification and reducing 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. Particularly preferred. When there is too little content of ^{P5 +} , the said effect will become difficult to be acquired. On the other hand, when the content of P ⁵⁺ is too large, the content of Sn ²⁺ becomes relatively small, and the refractive index tends to be lowered, and the weather resistance is likely to be lowered. 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. Most preferably.

Sn ²⁺ is an essential component for achieving high refractive index optical characteristics and improving chemical durability and weather resistance. It also has the effect of lowering the yield point. The content of Sn ²⁺ 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. When the content of Sn ²⁺ is too small, the above effect is difficult to obtain. On the other hand, when there is too much content of Sn2 ⁺ , it will become difficult to vitrify or devitrification resistance will fall easily. Therefore, the content of Sn ²⁺ 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. When the content of P ⁵⁺ + ^{Sn 2+} is too small, devitrification resistance and mechanical strength tends to decrease. The upper limit is not particularly limited, and the content of P ⁵⁺ + Sn ²⁺ may be 100%. However, when other components are contained, it is preferably 99.9% or less, and 99% or less. More preferably, it is more preferably 95% or less, and particularly preferably 90% or less.

  The glass powder may further contain the following components as a cation component.

B ³⁺ , Zn ²⁺ , Si ⁴⁺ and Al ³⁺ are components of the glass skeleton, and have a particularly large effect of improving chemical durability. The content of B ³⁺ + Zn ²⁺ + Si ⁴⁺ + Al ³⁺ is preferably 0 to 50%, more preferably 0 to 30%, still more preferably 0.1 to 25%, and more preferably 0.5 to It is particularly preferably 20%, and most preferably 0.75-15%. When the content of ^{B 3+ + Zn 2+ + Si 4+} + Al 3+ is too large, the devitrification resistance tends to decrease. Moreover, Sn metal etc. precipitate with a raise of melting temperature, and light transmittance becomes easy to fall. Also, the yield point tends to rise. Furthermore, it becomes difficult to obtain highly refractive glass. From the viewpoint of improving the weather resistance, it is preferable to contain 0.1% or more of B ³⁺ + Zn ²⁺ + Si ⁴⁺ + Al ³⁺ .

  In addition, the preferable content range of each component is as follows.

B ³⁺ is a component constituting the glass skeleton. Moreover, there exists an effect which improves a weather resistance, and especially the effect which suppresses that components, such as ^{P5 +} in glass, elute selectively into water is large. The content of B ³⁺ is preferably 0 to 50%, more preferably 0.1 to 45%, and still more preferably 0.5 to 40%. When there is too much content of ^{B3 +} , a refractive index and devitrification resistance will fall easily. Moreover, there exists a tendency for light transmittance to fall.

Zn ²⁺ is a component that acts as a flux. Moreover, there exists an effect which improves a weather resistance, suppresses the elution of the glass component in various washing | cleaning solutions, such as polishing washing water, and suppresses the quality change of the glass surface in a hot and humid state. 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 still more preferably 0.2 to 20%. When there is too much content of Zn ^<2+> , light transmittance will fall or it will become easy to devitrify.

Si ^{4+ is} also a component constituting the glass skeleton. Moreover, there exists an effect which improves a weather resistance, and especially the effect which suppresses that components, such as ^{P5 +} in glass, elute selectively into water is large. The content of Si ⁴⁺ is preferably 0 to 20%, and more preferably 0.1 to 15%. When there is too much content of ^{Si4 +} , a refractive index will fall or a yield point will become high easily. In addition, striae and bubbles due to undissolved are likely to remain in the glass.

Al ³⁺ is a component capable of constituting a glass skeleton together with Si ⁴⁺ and B ³⁺ . Moreover, there exists an effect which improves a weather resistance, and especially the effect which suppresses that components, such as ^{P5 +} in glass, elute selectively into water is large. The content of Al ³⁺ is preferably 0 to 20%, and more preferably 0.1 to 15%. When there is too much content of ^{Al3 +} , it will become easy to devitrify. Moreover, there exists a tendency for light transmittance to fall. Further, the melting temperature is increased, and striae and bubbles due to undissolution are likely to remain in the glass.

Mg ²⁺ , Ca ²⁺ , Sr ²⁺ and Ba ²⁺ (alkaline earth metal ions) are components that act as fluxes. Moreover, there exists an effect which improves a weather resistance, suppresses the elution of the glass component in various washing | cleaning solutions, such as polishing washing water, and suppresses the quality change of the glass surface in a hot and humid state. Moreover, it is a component which raises the hardness of glass. However, when there is too much content of these components, liquidus temperature rises (liquidus viscosity falls), and there exists a tendency for a devitrification thing to precipitate easily during a melting or shaping | molding process. As a result, mass production is difficult. These components have a feature that the refractive index does not fluctuate greatly. 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%. The content is 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 ⁺ is eluted from the glass powder, the emission of the phosphor may be significantly reduced. Therefore, the content of Li ⁺ 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 effect of lowering the softening point, like Li ⁺ . 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 decrease significantly, or the generation of striae tends to be promoted. Moreover, liquidus temperature rises and a devitrification thing precipitates easily in glass. In addition, Li ⁺ tends to reduce chemical durability and light transmittance. Furthermore, when Na ⁺ is eluted from the glass powder, the light 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%.

K ⁺ also has the effect of lowering the softening point, like Li ⁺ . Further, the refractive index can be improved by substituting with B ³⁺ , Si ⁴⁺ or Al ³⁺ . However, when there is too much the content, there exists a tendency for a refractive index to fall significantly or for a weather resistance to fall. Moreover, liquidus temperature rises and a devitrification thing precipitates easily in glass. Furthermore, when K ⁺ elutes from the glass powder, the emission of the phosphor may be significantly reduced. K ⁺ tends to reduce chemical durability and light transmittance. Therefore, the content of K ₂ O is preferably 0 to 10%, more preferably 0 to 5%, still more preferably 0 to 1%, and 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%. It is particularly preferred that When there is too much content of Li ^< + ^> + Na ^< + ^> + K ^{< +} >, it will become easy to devitrify and there exists a tendency for chemical durability to fall. Moreover, it becomes difficult to obtain desired optical characteristics.

In addition, you may contain Cs ^<+> as an alkali metal component. Cs ⁺ has the effect of lowering the softening point. However, when there is too much the content, there exists a tendency for a refractive index to fall significantly or for a weather resistance to fall. 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 even more preferably not contained.

La ³⁺ and Gd ³⁺ are components that improve the refractive index without substantially reducing the light transmittance. However, when there is too much the content, devitrification resistance will fall easily. Therefore, the content of these components is preferably 0 to 10%, more preferably 0.1 to 7.5%, and still more preferably 1 to 5%.

Ta ⁵⁺ , W ⁶⁺ and Nb ⁵⁺ have the effect of increasing the refractive index without substantially reducing the light transmittance. However, when there is too much the content, devitrification resistance will fall easily. Therefore, the content of these components is preferably 0 to 10%, more preferably 0.1 to 7.5%, and still more preferably 1 to 5%.

Ti ⁴⁺ is a component that has the effect of increasing the refractive index. Moreover, it is a component effective in 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 a large amount of Fe component is contained in the glass as an impurity (for example, 20 ppm or more), the light transmittance tends to be significantly reduced. Further, the devitrification resistance is likely to be lowered. Therefore, the content of Ti ⁴⁺ is preferably 0 to 10%, more preferably 0.1 to 7.5%, and still more preferably 1 to 5% or less.

Y ³⁺ , Yb ³⁺ and Ge ⁴⁺ have the effect of increasing the refractive index without substantially reducing the light transmittance. However, when there is too much the content, devitrification resistance will fall easily. Therefore, the content of these components is preferably 0 to 10%, more preferably 0.1 to 7.5%, and still more preferably 1 to 5%.

Te ⁴⁺ and Bi ³⁺ are components that ^tend to lower the light transmittance, and particularly under melting conditions with a low oxygen concentration, blackening occurs and the light transmittance is remarkably lowered. Accordingly, the Te ⁴⁺ and Bi ³⁺ contents are each 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 with 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 preferred. When there is too much content of Zr4 ⁺ , devitrification resistance will fall easily or a melting temperature will rise and light transmittance will fall easily.

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%, 0.2 More preferably, it is -5%, and it is most preferable that it is 0.3-2.5%. La ³⁺ + Gd ³⁺ + Ta ⁵⁺ + W ⁶⁺ + Nb ⁵⁺ + Ti ⁴⁺ + Y ³⁺ + Yb ³⁺ + Ge ^{4+ If} the content is too high, the devitrification resistance tends to decrease, or the melting temperature rises 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 these components is preferably 0.1% or less, and more preferably not contained.

Moreover, since rare earth components such as Ce ⁴⁺ , Pr ³⁺ , Nd ³⁺ , Eu ³⁺ , Tb ^3+, and Er ³⁺ may also reduce the light transmittance, the content of these components is less than 0.1%, respectively. It is preferable that it is not contained.

Since In ³⁺ has a strong devitrification tendency, it is preferably not contained.

Incidentally, for environmental reasons, it is preferred not to contain ^{Pb 2+} and ^{As 3+.}

The glass powder in the present invention contains F ⁻ or Cl ⁻ which is a halide ion 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 striae easily occurs. Moreover, 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% Is more preferable, F ⁻ + Cl ⁻ 2 to 30% is further preferable, and F ⁻ + Cl ⁻ 10 to 60% is particularly preferable. In addition, as a raw material for introducing F ⁻ and Cl ⁻ , fluorides of La, Gd, Ta, W, Nb, Y, Yb, Ge, Mg, Ca, Sr or Ba are available in addition to SnF ₂ and SnCl _2. And chloride.

As halide ions, in addition to the above components, Br ⁻ or the like may be contained. In general, oxygen ions (O ²⁻ ) are contained other than halide ions.

  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 light extraction efficiency from the wavelength conversion member tends to decrease. Further, the difference in refractive index between the glass powder and the phosphor increases, and the light scattering loss at the interface between the two increases, which may reduce the emission intensity. The upper limit is not particularly limited, but if the refractive index is too high, the glass tends to become unstable, and is preferably 1.95 or less, more preferably 1.9 or less.

The coloring degree 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. When the coloring degree 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 applied to the phosphor is reduced, and it is 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 less, more preferably 280 ° C. or less, further preferably 260 ° C. or less, and particularly preferably 250 ° C. or less. When the yield point of the glass powder satisfies the above range, sintering at a low temperature is possible, and deterioration of the phosphor can be suppressed.

  In the powder glass of the present invention, the difference between the softening temperature (TF) and the crystallization temperature (Tc) is preferably 30 ° C. or more, more preferably 40 ° C. or more, and further preferably 50 ° C. or more. 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 reduced, or the sintering is insufficient and it becomes difficult to obtain a dense sintered body.

The thermal expansion coefficient at 20 to 100 ° C. of the glass powder 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. is more preferable. If the thermal expansion coefficient is too low or too high, the thermal expansion coefficients of the base material for fixing the wavelength conversion member and the adhesive for bonding the wavelength conversion member and the base material will not match, Cracks are likely to occur during use.

  It is preferable that the water resistance of the glass powder in accordance with JOGIS is at least tertiary. When the water resistance is out of the above range, the light transmittance may be reduced due to white turbidity in the manufacturing process (for example, the cleaning process) of the wavelength conversion member.

The glass powder can be produced as follows. First, after preparing raw materials so as to have a desired composition, melting is performed in a melting furnace. As raw materials, oxides, carbonates, nitrates, phosphates, halogen compounds (fluorides, chlorides, bromides, iodides, astatides) and the like can be used. Here, after producing a cullet by primary melting, secondary melting is performed using the cullet, whereby the refractive index can be adjusted and the composition can be homogenized. By homogenizing the composition, a glass having a high light transmittance can be obtained. In the 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, it is easy to obtain a homogeneous glass by melting in an inert atmosphere such as nitrogen or argon. As the glass melting container, metals such as platinum and gold, refractories, quartz glass, glassy carbon and the like can be used. In particular, a gold container is preferable because an alloy reaction with Sn ²⁺ hardly occurs. As metal container, it is preferable to use a reinforcement is dispersed oxides such as ZrO _2.

  Next, the molten glass is formed into a film and a powder glass is obtained using a ball mill.

The particle size of the glass powder is not particularly limited, for example, the maximum particle diameter _{D 99} is 200μm or less (especially 150μm or less, more 105μm or less), and an average particle diameter _{D 50} of more than 0.1 [mu] m (in particular 1μm or more, further Is preferably 2 μm or more. If the maximum particle diameter D ₉₉ of the glass powder is too large, in the wavelength conversion member, the light emission efficiency becomes excitation light is less likely to scatter tends to decrease. When the average particle diameter D ₅₀ is too small, in the wavelength conversion member, the light emission efficiency tends to decrease with the excitation light is excessively scattered.

In the present invention, the average particle diameter D ₅₀ and the maximum particle diameter D ₉₉ indicate values measured by a 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 phosphors such as YAG phosphors), sulfide phosphors, oxysulfide phosphors, halide phosphors (halophosphates) Product phosphors) and aluminate phosphors. 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 difficult to deteriorate during firing. Nitride phosphors and oxynitride phosphors are characterized by converting near-ultraviolet to blue excitation light into a wide wavelength range from green to red and having a relatively high emission intensity. Therefore, nitride phosphors and oxynitride phosphors are particularly effective as phosphors used for wavelength conversion members for white LED elements.

  Examples of the phosphor include those having 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), yellow (wavelength 540 to 595 nm). ) Or red (wavelength of 600 to 700 nm).

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

SrAl ₂ O ₄ : Eu ²⁺ , SrBaSiO ₄ : Eu ²⁺ , Y ₃ (Al, Gd) ₅ O ₁₂ : as phosphors emitting green fluorescence when irradiated with ultraviolet to near-ultraviolet excitation light having a wavelength of 300 to 440 nm 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.

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

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

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⁺ .

As phosphors emitting red fluorescence when irradiated with ultraviolet to near-ultraviolet excitation light having a wavelength of 300 to 440 nm, CaGa ₂ S ₄ : Mn ²⁺ , MgSr ₃ Si ₂ O ₈ : Eu ²⁺ , Mn ²⁺ , Ca ₂ MgSi ₂ ^Examples include O ₇ : Eu ²⁺ , Mn ^{2+ and the} like.

As phosphors that emit red fluorescence when irradiated with blue excitation light having a wavelength of 440 to 480 nm, CaAlSiN ₃ : Eu ²⁺ , CaSiN ₃ : Eu ²⁺ , (Ca, Sr) ₂ Si ₅ N ₈ : Eu ²⁺ , α− SiAlON: Eu < ²⁺ > etc. are mentioned.

  In addition to the above phosphor, a quantum dot phosphor can 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. The quantum dot phosphor is usually handled in a state dispersed in an organic solvent.

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

  When there is too much content of the fluorescent substance in a wavelength conversion member, it will become difficult to sinter and there exists a tendency for a porosity to become large. As a result, in the obtained wavelength conversion member, problems such as it becomes difficult for the excitation light to be efficiently irradiated onto the phosphor, and the mechanical strength tends to decrease. On the other hand, if the phosphor content is too small, it becomes difficult to obtain a desired emission intensity. From such a viewpoint, the content of the phosphor in the wavelength conversion member is mass%, preferably 0.01 to 50%, more preferably 0.05 to 40%, and still more preferably 0.1 to 30%. Adjusted in range.

  Note that the wavelength conversion member for the purpose of reflecting the fluorescence generated in the wavelength conversion member to the excitation light incident side and mainly taking out only the fluorescence to the outside is not limited to the above, and the emission intensity is maximized. In this way, the content of the phosphor can be increased (for example, in mass%, 50% to 80%, and further 55 to 75%).

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

  In addition, the wavelength conversion member of the present invention may be formed by directly charging the phosphor during the melting of the glass having the above composition and uniformly dispersing 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. Alternatively, the phosphor layer may be formed by applying a mixture of the glass powder and the phosphor on the substrate and heating the mixture to sinter the mixture of the glass powder and the phosphor. Examples of the substrate 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. In addition, after disperse | distributing fluorescent substance on the base-material surface and mounting the glass plate which has the said composition on it further, you may soften a glass plate by heating and seal fluorescent substance. Alternatively, the phosphor is dispersed on the surface of the glass plate having the above composition, and after placing another glass plate having the above composition thereon, the glass plate is softened by heating to seal the phosphor. May be. After sandwiching the phosphor in a dispersed state 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 wavelength conversion member is preferably within the softening point of glass powder within ± 100 ° C, within ± 80 ° C, and more preferably 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 phosphor is eluted into the glass powder, the components contained in the phosphor are diffused into the glass powder, and the glass powder is colored. There is a fear.

  The atmosphere during firing is preferably an air atmosphere or an inert atmosphere such as 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 the deterioration of the light emission characteristics of a phosphor having a relatively low heat resistance (such as a quantum dot phosphor). As a result, the emission intensity of the wavelength conversion member can be improved.

  The shape of the wavelength conversion member of the present invention is not particularly limited. For example, a plate shape, a column shape, a spherical shape, a hemispherical shape, a hemispherical dome shape, etc. It may be a film formed on the surface of the substrate.

The light emitting device of the present invention includes the wavelength conversion member described above 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 a 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 wavelength conversion and the excitation light transmitted without wavelength conversion may be emitted, or only the light after wavelength conversion may be emitted.

  EXAMPLES Hereinafter, although this invention is demonstrated in detail based on an Example, this invention is not limited to these Examples.

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

  First, raw materials were prepared so as to have the glass compositions shown in the table, and melted at 700 to 1000 ° C. for 1 hour using a gold crucible. The obtained molten glass was formed into a film and pulverized with a ball mill to obtain 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 be molded into a size of 50 mm × 50 mm × 15 mm to prepare a measurement sample.

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

  The refractive index is indicated by the measured value for the d-line (587.6 nm) of the helium lamp.

  The thermal expansion coefficient and yield point were measured using a thermal expansion measuring device (dilatometer). In addition, the thermal expansion coefficient was measured in the temperature range of 20-100 degreeC.

  The softening temperature (TF) and the crystallization temperature (Tc) were measured with a differential calorimeter.

The degree of coloring was measured as follows. For the 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 a coloring degree λ ₇₀ .

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

(2) Preparation of wavelength conversion member Tables 3-5 show the wavelength conversion member which concerns on an Example (No. 1-10, 12-21, 23-32) and a comparative example (No. 11, 22, 33). Yes.

Each glass powder sample described in Tables 1 and 2 was mixed with CaAlSiN ₃ or α-SiAlON as a phosphor at a predetermined mass ratio shown in Tables 3 and 4 to obtain a mixed powder. The mixed powder was pressure-molded with a mold to prepare a cylindrical preform with a diameter of 1 cm. Further, each glass powder shown in Tables 1 and 2 is pressure-molded with a mold to produce a cylindrical green compact having a diameter of 1 cm, and a solvent in which quantum dot phosphor PbS is dispersed as a phosphor is added to this pressure. A cylindrical preform was obtained by dripping and impregnating the powder. The mixing ratio of the glass powder and PbS was as shown in Table 5. Each of the obtained preforms is fired at a temperature of the softening temperature of glass powder + 30 ° C., and then the obtained sintered body is processed to obtain a disk-shaped wavelength conversion member having a diameter of 8 mm and a thickness of 0.2 mm. Got. About each obtained wavelength conversion member, the emission spectrum was measured and luminous efficiency was computed. The results are shown in Tables 3-5.

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

As is apparent from Tables 3 to 5, when CaAlSiN ₃ is used as the phosphor, No. 1 as an example. Samples 1 to 10 had a luminous efficiency of 6.4 lm / W or higher, whereas No. Eleven samples had a low luminous efficiency of 5.0 lm / W.

  When α-SiAlON is used as the phosphor, No. 1 as an example. The samples Nos. 12 to 21 had a luminous efficiency of 7.9 lm / W or more, whereas No. The 22 samples had a low luminous efficiency of 6.5 m / W.

  When quantum dot phosphor PbS is used as the phosphor, No. 1 as an example. The samples Nos. 23 to 32 had a luminous efficiency of 4.9 lm / W or more, whereas the No. Sample 33 did not emit light due to deterioration of the quantum dot phosphor.

  No. Since the wavelength conversion members 1 to 10, 12 to 21, 23 to 32 are prepared using a glass powder sample having excellent acid resistance and water resistance, the surface hardly changes even when used over a long period of time. It is considered that the light emission efficiency itself is hardly lowered.

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

DESCRIPTION OF SYMBOLS 1 Light emitting device 2 Wavelength conversion member 3 Light source

Claims (13)

A glass powder containing, in terms of cation%, P ⁵⁺ 10 to 70% or more, and Sn ²⁺ 15 to 85% or more, P ⁵⁺ + Sn ²⁺ 70.5% or more, anion%, F ⁻ 0.1 to 70%, A wavelength conversion member comprising a sintered body of a raw material powder for a wavelength conversion member including a 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, wherein the glass powder does not contain Pb ²⁺ and As ³⁺ . 4. The wavelength conversion member according to claim 1, wherein the glass powder contains 0% to 50% of B ³⁺ + Zn ²⁺ + Si ⁴⁺ + Al ³⁺ in cation%. 5. 5. The wavelength conversion member according to claim 1, wherein the glass powder contains 0% to 10% of Mg ²⁺ + Ca ²⁺ + Sr ²⁺ + Ba ²⁺ in terms of cation%.   The wavelength conversion member according to any one of claims 1 to 5, wherein the refractive index of the glass powder is 1.6 or more.   The wavelength conversion member according to any one of claims 1 to 6, wherein a yield point of the glass powder is 300 ° C or lower.   The wavelength conversion member according to claim 1, wherein the glass powder has a water resistance based on JOGIS of 3 or more. The wavelength conversion member according to claim 1, wherein the glass powder has a coloring degree λ ₇₀ of less than 500 nm.   The phosphor is selected from a nitride phosphor, an oxynitride phosphor, an oxide phosphor, a sulfide phosphor, an oxysulfide phosphor, a halide phosphor, an aluminate phosphor, and a quantum dot phosphor. The wavelength conversion member according to claim 1, wherein the wavelength conversion member is one or more types. ^Cationic%, P 5+ 10 to 70%, and ^{Sn 2+ 15~85%, P 5+ +} Sn 2+ 70.5% or more, ^anionic%, F - phosphor in the glass matrix containing 0.1 to 70% A wavelength conversion member characterized by being dispersed.   The wavelength conversion member according to any one of claims 1 to 11, wherein a difference between a softening temperature and a crystallization temperature of the glass powder is 30 ° C or more.   A light emitting device comprising: the wavelength conversion member according to claim 1; and a light source that irradiates the wavelength conversion member with excitation light of the phosphor.