JP2018027877A - Phase splitting glass - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide glass which can reduce light enclosed in glass without forming a light extraction layer consisting of a sintered compact.SOLUTION: In phase splitting glass having at least a first phase and a second phase, the average number density of phase splitting particles per 1 μmis 0.5-100.SELECTED DRAWING: None

Description

  The present invention relates to a phase separation glass, and specifically relates to a phase separation glass having a light scattering function.

  In recent years, energy consumed in living spaces such as homes has increased due to the widespread use, increase in size, and multifunctionality of home appliances. In particular, the energy consumption of lighting equipment is increasing. For this reason, highly efficient illumination is actively studied.

  Illumination light sources are classified into “directional light sources” that illuminate a limited range and “diffuse light sources” that illuminate a wide range. LED lighting corresponds to a “directional light source” and is being adopted as an alternative to an incandescent bulb. On the other hand, an alternative light source for a fluorescent lamp corresponding to a “diffusion light source” is desired, and organic EL (electroluminescence) illumination is a promising candidate.

  The organic EL element includes a glass plate, a transparent conductive film as an anode, an organic EL layer including an organic compound that exhibits electroluminescence that emits light by current injection, and a cathode, and a cathode. Element. As the organic EL layer used in the organic EL element, a low molecular dye material, a conjugated polymer material or the like is used. When forming a light emitting layer, a hole injection layer, a hole transport layer, an electron transport layer, an electron injection A laminated structure with layers and the like is formed. An organic EL layer having such a laminated structure is disposed between the anode and the cathode, and by applying an electric field to the anode and the cathode, holes injected from the transparent electrode that is the anode and those injected from the cathode The electrons recombine in the light emitting layer, and the emission center is excited by the recombination energy to emit light.

  Organic EL elements have been studied for use in mobile phones and displays, and some have already been put into practical use. An organic EL display using an organic EL element has a light emission efficiency equivalent to that of a thin television such as a liquid crystal display or a plasma display.

  However, in order to apply the organic EL element to the light source for illumination, the luminance has not yet reached the practical level, and further improvement of the light emission efficiency is necessary.

JP 2012-25634 A

  One cause of the decrease in luminance is that light is confined inside the glass plate due to a difference in refractive index between the glass plate and air. For example, when a glass plate having a refractive index nd of 1.50 is used, since the refractive index nd of air is 1.00, the critical angle is calculated as 42 ° from Snell's law. Therefore, light having an incident angle greater than the critical angle causes total reflection, is confined inside the glass plate, and is not extracted into the air.

  In order to solve the above problem, it has been studied to form a light extraction layer between a transparent conductive film or the like and a glass plate. For example, in Patent Document 1, a light extraction layer in which glass frit is sintered is formed on the surface of a soda glass plate, and light scattering efficiency is increased by dispersing a scattering substance in the light extraction layer. Have been described.

  However, in order to form the light extraction layer on the surface of the glass plate, a printing step of applying a glass paste to the surface of the glass plate is required, and this step causes an increase in production cost. Further, when the scattering particles are dispersed in the glass frit, the transmittance of the light extraction layer is lowered due to the absorption of the scattering particles themselves.

  The present invention has been made in view of the above circumstances, and its technical problem is to devise a glass capable of reducing light trapped in the glass without forming a light extraction layer made of a sintered body. It is.

As a result of intensive studies, the present inventors have found that the above technical problem can be solved by using a phase separation glass and regulating the average number density of phase separation particles of the phase separation glass within a predetermined range. It is proposed as the present invention. That is, the phase-separated glass of the present invention is characterized in that, in a phase-separated glass having at least a first phase and a second phase, the average number density of phase-separated particles per 1 μm ² is 0.5 to 100. And Here, “average number density of phase-separated particles per 1 μm ² ” means, for example, that phase-separated glass is immersed in a 2% by volume hydrofluoric acid solution for 2 minutes, and then the phase-separated particles on the etched surface are subjected to field emission. This can be confirmed by observing with a scanning electron microscope and measuring the average number per 1 μm ² from the observation screen.

  The phase separation glass of the present invention has at least a first phase and a second phase. As a result, the light incident on the glass plate from the organic EL layer is scattered at the interface between the first phase and the second phase, so that it is easy to extract the light into the air. The light extraction efficiency can be improved without forming a layer.

The phase-separated glass of the present invention has an average number density of phase-separated particles per 1 μm ² of 0.5 to 100. If it does in this way, the light which injected into the glass plate will be efficiently taken out in the air.

  Second, the phase-separated glass of the present invention preferably has an average particle diameter of phase-separated particles of 30 to 500 nm. If it does in this way, the light which injected into the glass plate will be efficiently taken out in the air. Here, the “average particle diameter of the phase-separated particles” is obtained by, for example, immersing the surface of phase-separated glass with a 2% by volume hydrofluoric acid solution for 2 minutes, and then etching the etched surface using a field emission scanning electron microscope. After observing and measuring the particle diameter with the image analysis software assuming that the phase-separated particles in the observation screen are circular, such measurement is performed on 10 or more phase-separated particles in the same observation screen. Then, it can be evaluated by calculating the average value.

  Third, the phase-separated glass of the present invention preferably has a thickness of more than 0.6 to 2.0 mm. If it does in this way, the light which injected into the glass plate can be taken out still more efficiently by the synergistic effect with the average number density of said phase-separated particle, and an average particle diameter.

Fourthly, the phase separation glass of the present invention preferably has a refractive index nd of 1.51 or more. Here, “refractive index nd” refers to the value of the d-line measured by a refractive index measuring device. For example, a rectangular parallelepiped sample of 25 mm × 25 mm × about 3 mm was first prepared, and the temperature range from (annealing point + 30 ° C.) to (strain point−50 ° C.) was gradually cooled at a cooling rate of 0.1 ° C./min. Thereafter, measurement can be performed by using a refractive index measuring device KPR-2000 manufactured by Shimadzu Corporation while infiltrating an immersion liquid having a matching refractive index. In conventional organic EL devices such as organic EL lighting, the light incident from the organic EL layer is reflected at the interface between the glass plate and the transparent conductive film due to the large difference in refractive index between the glass plate and the transparent conductive film. However, there is also a problem that the light extraction efficiency is lowered. Specifically, the refractive index nd of the transparent conductive film is 1.9 to 2.0, a refractive index _{n d} of the organic EL layer is 1.8 to 1.9, whereas the refractive glass plate The index nd is usually about 1.50, and the difference in refractive index between the two is large. Therefore, if the refractive index nd of the glass plate is regulated as described above, the difference in refractive index between the glass plate and the transparent conductive film becomes small, so that the light incident from the organic EL layer is the interface between the glass plate and the transparent conductive film. It becomes difficult to reflect.

Fifth, the phase-separated glass of the present invention contains, as a glass composition, by mass%, SiO ₂ 30 to 75%, Al ₂ O _{3 0 to} 35%, B ₂ O ₃ 0.1 to 50%. Is preferred. If it does in this way, phase separation property and devitrification resistance can be improved.

Sixth, in the phase-separated glass of the present invention, the total amount of SiO ₂ , Al ₂ O ₃ and B ₂ O _{3 in} the glass composition is preferably 50 to 80% by mass. If it does in this way, devitrification resistance can further be improved.

Seventh, in the phase-separated glass of the present invention, the total amount of Li ₂ O, Na ₂ O and K ₂ O in the glass composition is preferably 5% by mass or less.

  Eighth, the phase-separated glass of the present invention preferably has a flat plate shape.

  Ninthly, it is preferable that the phase separation glass of the present invention has a forming and joining surface inside, that is, formed by an overflow down draw method.

  Tenth, the phase separation glass of the present invention is preferably used for organic EL lighting.

  Eleventh, the organic EL device of the present invention preferably comprises the above phase separation glass.

The phase separation glass of the present invention has a phase separation structure including at least a first phase and a second phase. And in the phase-separated glass of the present invention, the content of SiO ₂ in the first phase is preferably larger than the content of SiO ₂ in the second phase. If it does in this way, the refractive index of a 1st phase and a 2nd phase will become easy to differ, and the scattering function of a glass plate can be improved. The details of each phase can be confirmed by observing the surface of the sample after being immersed in a 2% by volume hydrofluoric acid solution for 2 minutes with a field emission scanning electron microscope.

In the phase separation glass of the present invention, the average number density of phase separation particles per 1 μm ² is 0.5 to 100 particles. If the average number density of phase-separated particles per 1 μm ² is too small, light incident on the glass plate is not sufficiently scattered inside the glass plate, and much light remains confined inside the glass plate. Therefore, the average number density of phase-separated particles per 1 μm ² is preferably 0.6 or more, 1.0 or more, 1.4 or more, 1.8 or more, and particularly 2.0 or more. On the other hand, if the average number density of phase-separated particles per 1 μm ² is too large, light scattering becomes too strong inside the glass plate, and backscattering becomes dominant, making it difficult to extract light into the air. Therefore, the average number density of phase-separated particles per 1 μm ² is preferably 60 or less, 40 or less, 30 or less, and particularly 20 or less.

  In the phase-separated glass of the present invention, the average particle size of the phase-separated particles is preferably 30 to 500 nm. If the average particle size of the phase-separated particles is too small, the light incident on the glass plate is not sufficiently scattered inside the glass plate, and much light remains confined inside the glass plate. Therefore, the average particle diameter of the phase-separated particles is preferably 50 nm or more, 80 nm or more, 100 nm or more, particularly 120 nm or more. On the other hand, if the average particle size of the phase-separated particles is too large, light scattering becomes too strong inside the glass plate, so that backscattering becomes dominant and it becomes difficult to extract light into the air. Therefore, the average particle diameter of the phase-separated particles is preferably 400 nm or less, 300 nm or less, and particularly 200 nm or less.

  In the phase-separated glass of the present invention, the thickness is preferably more than 0.6 to 2.0 mm. If the thickness is too small, the light incident on the glass plate is not sufficiently scattered inside the glass plate, and much light remains confined inside the glass plate. Moreover, it becomes easy to break a glass plate. Therefore, the thickness is preferably 0.7 mm or more, particularly 1.0 mm or more. On the other hand, if the thickness is too large, the scattering of light becomes too strong inside the glass plate, the back scattering becomes dominant, and it becomes difficult to extract the light into the air. Accordingly, the thickness is preferably 1.6 mm or less, 1.4 mm or less, and particularly 1.2 mm or less.

  In the phase-separated glass of the present invention, the refractive index nd is preferably 1.51 or more, 1.52 or more, 1.53 or more, 1.54 or more, particularly 1.55 or more. If the refractive index nd is too low, light is easily reflected at the interface between the glass plate and the transparent conductive film, and it is difficult to extract the light into the air. On the other hand, if the refractive index nd is too high, introduction of a component that enhances devitrification resistance is restricted, so that it is difficult to increase the liquid phase viscosity. In addition, light is easily reflected at the interface between the glass plate and air, making it difficult to take out light into the air. Therefore, the refractive index nd is preferably 2.30 or less, 2.00 or less, 1.80 or less, 1.70 or less, particularly 1.65 or less.

The phase-separated glass of the present invention preferably contains, as a glass composition, 30 to 75% of SiO _{2, 0 to} 35% of Al ₂ O ₃ and 0.1 to 50% of B ₂ O ₃ as a glass composition. Hereinafter, the reason why each component is limited as described above will be described. In addition, in description of the containing range of each component,% display means the mass%.

When the content of SiO ₂ increases, the meltability and moldability tend to decrease, and the refractive index tends to decrease. Therefore, the preferable upper limit range of SiO ₂ is 75% or less, 70% or less, 65% or less, 60% or less, 55% or less, 50% or less, and particularly 48% or less. On the other hand, when the content of SiO ₂ decreases, it becomes difficult to form a glass network structure, and vitrification becomes difficult. Further, the viscosity of the glass is excessively lowered, and it becomes difficult to ensure a high liquid phase viscosity. Therefore, a suitable lower limit range of SiO ₂ is 30% or more, 32% or more, 34% or more, or 36% or more.

Al ₂ O ₃ is a component that enhances devitrification resistance. However, if the content of Al ₂ O ₃ is too large, the phase separation is liable to decrease, and the component balance of the glass composition is impaired. Conversely, devitrification resistance tends to decrease. Moreover, acid resistance tends to decrease. Therefore, the preferable upper limit range of Al ₂ O ₃ is 35% or less, 30% or less, 25% or less, 20% or less, 15% or less, 12% or less, 10% or less, particularly 9% or less. The range is 0% or more, 0.1% or more, 3% or more, 4% or more, especially 5% or more.

B ₂ O ₃ is a component that enhances phase separation, but if the content of B ₂ O ₃ is too large, the component balance of the glass composition is impaired, and devitrification resistance is likely to decrease. The acid resistance tends to decrease. Therefore, the preferable upper limit range of B ₂ O ₃ is 50% or less, 40% or less, 30% or less, 25% or less, 20% or less, 17% or less, particularly 15% or less. 1% or more, 0.5% or more, 1% or more, 4% or more, 7% or more, 9% or more, 10% or more, 11% or more, particularly 12% or more.

The total amount of SiO ₂ , Al ₂ O ₃ and B ₂ O ₃ is preferably 50 to 80%, 52 to 74%, 54 to 70%, particularly 54 to 68% from the viewpoints of refractive index and devitrification resistance. It is.

  In addition to the above components, for example, the following components can be introduced.

Li ₂ O, Na ₂ O and K ₂ O are components that lower the high temperature viscosity while increasing the phase separation, but if the total amount of Li ₂ O, Na ₂ O and K ₂ O is too large, The viscosity tends to decrease and the strain point tends to decrease. Furthermore, the alkali component is easily eluted in the acid etching step. Therefore, the preferable upper limit range of the total amount of Li ₂ O, Na ₂ O and K ₂ O is 30% or less, 20% or less, 10% or less, 5% or less, less than 1%, 0.5% or less, particularly 0 Less than 1%. A suitable upper limit range of Li ₂ O is 20% or less, 10% or less, 5% or less, less than 1%, 0.5% or less, particularly less than 0.1%. A preferable upper limit range of Na ₂ O is 30% or less, 20% or less, 10% or less, 5% or less, less than 1%, 0.5% or less, particularly less than 0.1%. A preferable upper limit range of K ₂ O is 20% or less, 10% or less, 5% or less, less than 1%, 0.5% or less, particularly less than 0.1%.

  MgO is a component that raises the refractive index, Young's modulus, and strain point and lowers the high-temperature viscosity. However, when MgO is contained in a large amount, the liquidus temperature rises and devitrification resistance decreases. Or the density may become too high. Therefore, the preferable upper limit range of MgO is 30% or less, 20% or less, 10% or less, 5% or less, and particularly less than 1%. In addition, the suitable lower limit range of MgO is 0% or more, 0.1% or more, 0.2% or more, and particularly 0.5% or more.

  CaO is a component that lowers the high-temperature viscosity. However, when the content of CaO increases, the density tends to increase, and the balance of components of the glass composition is impaired, and devitrification resistance tends to decrease. Therefore, the preferable upper limit range of CaO is 30% or less, 20% or less, 10% or less, 8% or less, 5% or less, 3% or less, 2% or less, particularly 1% or less. % Or more, 0.1% or more, particularly 0.5% or more.

  If the SrO content is increased, the refractive index and the density are likely to be increased, and the balance of components of the glass composition is impaired, so that the devitrification resistance is likely to be lowered. Therefore, the preferred upper limit range of SrO is 30% or less, 25% or less, 20% or less, 15% or less, particularly 12% or less, and the preferred lower limit range is 0% or more, 1% or more, 3% or more, 5% or less. % Or more, 7% or more, particularly 8% or more.

  BaO is a component that increases the refractive index of alkaline earth metal oxides without extremely reducing the viscosity of the glass. If the content of BaO increases, the refractive index tends to increase, and if the content of BaO is too large, the density tends to increase, and the balance of the components of the glass composition is impaired, resulting in a decrease in devitrification resistance. It becomes easy. Therefore, the preferable upper limit range of BaO is 40% or less, 30% or less, 26% or less, 24% or less, 22% or less, particularly 20% or less, and the preferable lower limit range is 0% or more, 1% or more, 5 % Or more, 7% or more, 10% or more, 12% or more, 14% or more, particularly 15% or more.

  When the ZnO content increases, the refractive index tends to increase, but the density tends to increase, and the balance of the components of the glass composition is impaired, and the devitrification resistance tends to decrease. Therefore, the preferable upper limit range of ZnO is 20% or less, 10% or less, 7% or less, 5% or less, particularly 4% or less, and the preferable lower limit range is 0% or more, 0.1% or more, 0.5% or less. % Or more, 1% or more, 1.5% or more, particularly 2% or more.

The total amount of MgO, CaO, SrO, BaO and ZnO is preferably 15 to 45%, 20 to 40%, particularly 25 to 35% from the viewpoint of achieving both a refractive index and resistance to devitrification. Further, the mass ratio (total amount of SiO ₂ , Al ₂ O ₃ and B ₂ O ₃ ) / (total amount of MgO, CaO, SrO, BaO and ZnO) is from the viewpoint of achieving both refractive index and devitrification resistance, Preferably they are 1.0-4.0, 1.4-3.0, especially 2.0-3.0.

TiO ₂ is a component that increases the refractive index. However, when the content of TiO ₂ increases, the component balance of the glass composition is impaired, and the devitrification resistance is likely to decrease. Therefore, a preferable upper limit range of TiO ₂ is 20% or less, 15% or less, 10% or less, particularly 8% or less, and a preferable lower limit range is 0% or more, 0.001% or more, 0.01% or more, It is 0.1% or more, 1% or more, 1.5% or more, particularly 2% or more.

ZrO ₂ is a component that increases the refractive index. However, when the content of ZrO ₂ increases, the component balance of the glass composition is impaired, and the devitrification resistance is likely to decrease. Therefore, the preferable upper limit range of ZrO ₂ is 20% or less, 10% or less, 6% or less, 4% or less, 3% or less, particularly 2% or less, and the preferable lower limit range is 0% or more and 0.001%. Above, 0.01% or more, 0.1% or more, 0.5% or more, particularly 1% or more.

P ₂ O ₅ is a component that improves phase separation. However, when the content of P ₂ O ₅ is increased, the component balance of the glass composition is impaired, and devitrification resistance is likely to be reduced. Therefore, a suitable upper limit range of P ₂ O ₅ is 20% or less, 15% or less, 10% or less, 7% or less, 4% or less, 3% or less, particularly 2.5% or less. It is 0% or more, 0.001% or more, 0.01% or more, 0.1% or more, 0.5% or more, 1% or more, 1.2% or more, particularly 1.4% or more.

_{La 2 O 3, Nb 2 O} 5 and _Gd 2 _{O 3} is a component to increase the refractive index, when the content thereof increases, tends to become denser, and the devitrification resistance and acid resistance is lowered It becomes easy. Furthermore, the raw material cost rises, and the manufacturing cost of the glass plate is likely to rise. Accordingly, suitable upper limit ranges of La ₂ O ₃ , Nb ₂ O ₅ and Gd ₂ O ₃ are 10% or less, 5% or less, 3% or less, 1% or less, 0.5% or less, particularly 0.1%, respectively. % Or less.

Rare metal oxide is a component that increases the refractive index, but as the content of these components increases, the density and thermal expansion coefficient tend to increase, and devitrification resistance decreases, ensuring high liquid phase viscosity. It becomes difficult to do. Furthermore, the raw material cost rises, and the manufacturing cost of the glass plate is likely to rise. Therefore, a preferable upper limit range of the rare metal oxide is 10% or less, 5% or less, 3% or less, 1% or less, 0.5% or less, particularly 0.1% or less. The “rare metal oxide” as used in the present invention is a rare earth oxide such as La ₂ O ₃ , Nd ₂ O ₃ , Gd ₂ O ₃ , CeO ₂ , Y ₂ O ₃ , Nb ₂ O ₅ , Ta ₂ O _5. Point to.

As a refining agent, one or two or more selected from the group of As ₂ O ₃ , Sb ₂ O ₃ , SnO ₂ , Fe ₂ O ₃ , F, Cl, SO ₃ , and CeO ₂ are converted into the following oxides. ~ 1% can be introduced. In particular, SnO ₂ , Fe ₂ O ₃ and CeO ₂ are preferable as the fining agent. On the other hand, it is preferable to refrain from using As ₂ O ₃ and Sb ₂ O ₃ as much as possible from an environmental point of view. Each content is less than 0.3%, less than 0.1%, particularly less than 0.01%. Is preferred. Here, “the following oxide conversion” means that an oxide having a valence different from the indicated oxide is handled after being converted to the indicated oxide.

The content of SnO ₂ is preferably 0 to 1%, 0.001 to 1%, particularly 0.01 to 0.5%.

The content of Fe ₂ O ₃ is preferably 0.05% or less, 0.04% or less, 0.03% or less, particularly 0.001 to 0.02%.

The content of CeO ₂ is preferably 0 to 6%. When the content of CeO ₂ is increased, the devitrification resistance is likely to be lowered. Therefore, the preferable upper limit range of CeO ₂ is 5% or less, 3% or less, 2% or less, 1% or less, particularly 0.1% or less. On the other hand, when CeO ₂ is introduced, a suitable lower limit range of CeO ₂ is 0.001% or more, particularly 0.01% or more.

  PbO is a component that lowers the high-temperature viscosity, but it is preferable to refrain from using it as much as possible from an environmental point of view. The PbO content is preferably 0.5% or less, particularly preferably less than 0.1%.

  In addition to the above components, other components may be introduced in a total amount of preferably 10% (desirably 5%, more desirably 2%).

  The phase-separated glass of the present invention preferably has the following characteristics.

  The strain point is preferably 450 ° C. or higher, 500 ° C. or higher, 550 ° C. or higher, particularly 600 ° C. or higher. The higher the temperature of the transparent conductive film, the higher the transparency and the lower the electrical resistance. However, since the conventional glass plate has insufficient heat resistance, it has been difficult to form a transparent conductive film at a high temperature. Therefore, if the strain point is in the above range, the heat resistance is improved, so that both transparency of the transparent conductive film and low electrical resistance can be achieved. Further, in the organic device manufacturing process, the glass plate is heated by heat treatment. It becomes difficult to shrink.

The temperature at a high temperature viscosity of 10 ^2.5 dPa · s is preferably 1450 ° C. or lower, 1400 ° C. or lower, 1380 ° C. or lower, particularly 1360 ° C. or lower. If it does in this way, since a meltability will improve, productivity of a glass plate will improve.

The liquid phase viscosity is preferably 10 ^3.0 dPa · s or more, 10 ^3.2 dPa · s or more, 10 ^3.4 dPa · s or more, 10 ^3.6 dPa · s or more, 10 ^3.8 dPa · s or more. In particular, it is 10 ^4.0 dPa · s or more. The liquidus temperature is preferably 1200 ° C. or lower, 1150 ° C. or lower, 1100 ° C. or lower, particularly 1060 ° C. or lower. If the liquidus viscosity is too low or the liquidus temperature is too high, the glass tends to devitrify during molding, and for example, it becomes difficult to form a glass plate by an overflow downdraw method, a float method, or the like. Here, the “liquid phase viscosity” is obtained after passing through 30 mesh (a sieve opening of 500 μm) and putting glass powder remaining in a 50 mesh (a sieve opening of 300 μm) in a platinum boat and holding it in a temperature gradient furnace for 24 hours. The value which measured the temperature which crystal | crystallization precipitates is pointed out. “Liquid phase temperature” refers to a value obtained by measuring the viscosity of glass in the liquid phase viscosity by a platinum ball pulling method.

The phase separation temperature is preferably 700 ° C. or higher, 800 ° C. or higher, 850 ° C. or higher, 900 ° C. or higher, 950 ° C. or higher, 1000 ° C. or higher, particularly 1100 ° C. or higher. Moreover, phase separation viscosity is preferably ¹⁰ 9.0 dPa · s or ^{less, 10} 8.0 dPa · s or ^{less, 10} 7.0 dPa · s or less, in particular ¹⁰ 3.5 ^~10 6.0 dPa · s is there. If it does in this way, it will become easy to phase-separate glass and it will become easy to shape | mold the glass plate which has a phase-separation structure by the overflow downdraw method, the float glass method, etc. Here, “phase separation temperature” indicates that clear cloudiness is observed when a glass piece is placed in a platinum boat and remelted at 1400 ° C., then the platinum boat is transferred to a temperature gradient furnace and held in the temperature gradient furnace for 30 minutes. Temperature. “Phase separation viscosity” refers to a value obtained by measuring the viscosity of glass at the phase separation temperature by the platinum pulling method. In the phase-separated glass of the present invention, the average number density of the phase-separated particles is preferably controlled by a separate heat treatment step, but the average number density of the phase-separated particles is controlled in the molding step and / or the slow cooling step. In addition to these steps, for example, the average number density of the phase-separated particles may be controlled by a melting step. The phase separation structure can be controlled by the glass composition, molding conditions, slow cooling conditions, heat treatment conditions, and the like.

  The phase-separated glass of the present invention preferably has a flat plate shape, that is, a glass plate. If it does in this way, it will become easy to apply to an organic EL device. When it has a flat plate shape, it is preferable to have an unpolished surface on at least one surface (in particular, the entire effective surface of at least one surface is an unpolished surface). The theoretical strength of glass is very high, but breakage often occurs even at a stress much lower than the theoretical strength. This is because a small defect called Griffith flow occurs on the surface of the glass plate in a post-molding process such as a polishing process. Therefore, if the surface of the glass plate is unpolished, the original mechanical strength is hardly lost, and thus the glass plate is difficult to break. Further, since the polishing step can be simplified or omitted, the manufacturing cost of the glass plate can be reduced.

  When it has a flat plate shape, the surface roughness Ra of at least one surface (particularly the unpolished surface) is preferably 0.01 to 1 μm. When surface roughness Ra is large, when forming a transparent conductive film etc. on the surface, the quality of a transparent conductive film falls and it becomes difficult to obtain uniform light emission. Suitable upper limit ranges of the surface roughness Ra are 1 μm or less, 0.8 μm or less, 0.5 μm or less, 0.3 μm or less, 0.1 μm or less, 0.07 μm or less, 0.05 μm or less, 0.03 μm or less, particularly 10 nm. It is as follows.

  The phase separation glass of the present invention is preferably formed by a downdraw method, particularly an overflow downdraw method. In this way, it is possible to produce a glass plate that is unpolished and has good surface quality. The reason is that, in the case of the overflow down draw method, the surface to be the surface is not in contact with the bowl-shaped refractory and is molded in a free surface state. In addition to the overflow downdraw method, a slot downdraw method can be employed. If it does in this way, it will become easy to produce a thin glass plate.

  In addition to the above molding method, for example, a redraw method, a float method, a roll-out method, or the like can be employed. In particular, in the float process, a large glass plate can be efficiently formed.

  When the phase separation glass of the present invention has a flat plate shape, at least one surface may be a roughened surface. If the roughened surface is arranged on the side in contact with air such as organic EL lighting, in addition to the scattering effect of the glass plate, the non-reflective structure of the roughened surface allows light emitted from the organic EL layer to be within the organic EL layer. As a result, the light extraction efficiency can be increased. The surface roughness Ra of the roughened surface is preferably 10 mm or more, 20 mm or more, 30 mm or more, particularly 50 mm or more. The roughened surface can be formed by etching with hydrofluoric acid, sandblasting, or the like. Moreover, you may form a roughening surface (uneven surface) in the surface of a glass plate by heat processing, such as repress. In this way, an accurate non-reflective structure can be formed on the glass surface. What is necessary is just to adjust the space | interval and depth, considering the refractive index nd about the shape of an uneven surface.

Further, the roughened surface can be formed by an atmospheric pressure plasma process. If it does in this way, while maintaining the smooth surface state of one surface of a glass plate, a roughening process can be uniformly performed with respect to the other surface. Moreover, it is preferable to use a gas containing F (for example, SF ₆ , CF ₄ ) as a source of the atmospheric pressure plasma process. In this way, since plasma containing hydrofluoric acid gas is generated, the roughened surface can be formed efficiently.

  Furthermore, a roughened surface (uneven surface) can be formed on at least one surface during the molding of the glass plate. This eliminates the need for a separate roughening process and improves the efficiency of the roughening process.

  In addition, you may affix the resin film which has a predetermined uneven | corrugated shape on the surface of a glass plate, without forming a roughening surface in a glass plate. The uneven surface roughness Ra is preferably 10 mm or more, 20 mm or more, 30 mm or more, particularly 50 mm or more.

  The phase-separated glass of the present invention is preferably heat-treated after cutting. The heat treatment temperature is preferably 700 to 1000 ° C, particularly 800 to 900 ° C. The heat treatment time is preferably 5 to 500 minutes, 15 to 250 minutes, particularly 30 to 60 minutes. If it does in this way, it will become easy to control the average number density and average particle diameter of a phase-separated particle to an appropriate range.

  Hereinafter, based on an Example, this invention is demonstrated in detail. The following examples are merely illustrative. The present invention is not limited to the following examples.

  Table 1 shows Sample No. 1-8 are shown.

  First, after preparing a glass raw material so that it might become the glass composition of Table 1, the obtained glass batch was supplied to the glass melting furnace, and it melted at 1400 degreeC for 7 hours. Next, the obtained molten glass was poured onto a carbon plate, formed into a flat plate shape, and then gradually cooled by lowering the temperature range from the strain point to room temperature over 10 hours. Finally, the obtained glass plate was processed as necessary to evaluate various properties.

  Density refers to a value measured by Archimedes method.

  The thermal expansion coefficient is an average value measured with a dilatometer in a temperature range of 30 to 380 ° C.

  The strain point Ps is a value measured by the method described in ASTM C336-71. In addition, heat resistance becomes high, so that a strain point is high.

  The annealing point Ta and the softening point Ts are values measured by the method described in ASTM C338-93.

The temperatures at high temperature viscosities of 10 ^4.0 dPa · s, 10 ^3.0 dPa · s, 10 ^2.5 dPa · s, and 10 ^2.0 dPa · s are values measured by the platinum ball pulling method. In addition, it is excellent in a meltability, so that high temperature viscosity is low.

  The liquidus temperature passes through 30 mesh (500 μm sieve opening), and the glass powder remaining in 50 mesh (300 μm sieve opening) is placed in a platinum boat and held in a temperature gradient furnace for 24 hours, followed by crystal precipitation. Measured temperature. The liquid phase viscosity is a value obtained by measuring the viscosity of glass at the liquid phase temperature by a platinum ball pulling method.

  The phase separation temperature was measured at a temperature at which clear white turbidity was observed when a glass piece was put in a platinum boat and remelted at 1400 ° C., and then the platinum boat was transferred to a temperature gradient furnace and held in the temperature gradient furnace for 30 minutes. Is. The phase separation viscosity is a value obtained by measuring the viscosity of the glass at the phase separation temperature by a platinum ball pulling method.

  The refractive index nd is the value of the d line measured by a refractive index measuring instrument KPR-2000 manufactured by Shimadzu Corporation. Specifically, first, a rectangular parallelepiped sample of 25 mm × 25 mm × about 3 mm is prepared, and the temperature range from (annealing point Ta + 30 ° C.) to (strain point Ps−50 ° C.) is set at a cooling rate of 0.1 ° C./min. It is a value measured by allowing an immersion liquid having a matching refractive index nd to penetrate after annealing.

About the phase separation glass (sample No. 1-8) as described in the column of Example 1, it heat-processed at the heat processing temperature and heat processing time of Table 2. Next, after the phase-separated glass was immersed in a 2% by volume hydrofluoric acid solution for 2 minutes, the etched surface was observed with a field emission scanning electron microscope. From the observation screen, the phase-separated particles per 1 μm ^{2 were} observed. Average number density was measured. In addition, after measuring the particle diameter when the phase-separated particles in the observation screen are circular by using the separated graphic editing function of image analysis software (WinROOF, Mitani Corp.), the same measurement is performed. After performing with respect to 10 or more phase-separated particles in an observation screen, the average value of the phase-separated particles was evaluated by calculating the average value.

The light emission intensity ratio of the glass plate after heat treatment described in Table 2 (plate thickness: 0.7 mm) was evaluated. First, ITO (thickness 100 nm) was vapor-deposited as a transparent electrode layer using the mask on the surface of the glass plate. Subsequently, a polymer PEDOT-PSS (thickness 40 nm) as a hole injection layer, α-NPD (thickness 50 nm) as a hole transport layer, and Ir (ppy) ₃ as an organic light emitting layer 6% by mass were doped on ITO. CBP (thickness 30 nm), BAlq (thickness 10 nm) as a hole blocking layer, Alq (thickness 30 nm) as an electron transport layer, LiF (thickness 0.8 nm) as an electron injection layer, and Al (thickness 150 nm) as a counter electrode were formed. Then, the inside was sealed and the organic EL element was produced. An integrating sphere was placed on the light emitting surface of the obtained organic EL element, and the light emission intensity (count value) at a wavelength of 520 nm was measured. As a comparative example, the emission intensity was measured in the same manner when an organic EL device was produced by incorporating “OA-10G” (plate thickness 0.7 mm) manufactured by Nippon Electric Glass Co., Ltd. Finally, the emission intensity ratio for OA-10G was evaluated for each sample.

  As can be seen from Table 2, sample no. Each of the heat-treated samples 1 to 8 exhibited a higher emission intensity ratio than OA-10G because the average number density of the phase-separated particles was appropriately regulated.

Claims (11)

In a phase separation glass having at least a first phase and a second phase,
An average number density of phase-separated particles per 1 μm ² is 0.5 to 100.   The phase separation glass according to claim 1, wherein the average particle size of the phase separation particles is 30 to 500 nm.   The phase separation glass according to claim 1 or 2, wherein the thickness is more than 0.6 to 2.0 mm.   Refractive index nd is 1.51 or more, The phase separation glass in any one of Claims 1-3 characterized by the above-mentioned. As a glass composition, in _{mass%, SiO 2 30~75%, Al} 2 O 3 0~35%, any one of the preceding claims, characterized in that it contains 2 O 3 0.1~50% _B The phase separation glass described in 1. 6. The phase-separated glass according to claim 1, wherein the total amount of SiO ₂ , Al ₂ O ₃ and B ₂ O _{3 in} the glass composition is 50 to 80% by mass. The phase separation glass according to claim 1, wherein the total amount of Li ₂ O, Na ₂ O and K ₂ O in the glass composition is 5% by mass or less.   The phase-separated glass according to claim 1, which has a flat plate shape.   The phase separation glass according to any one of claims 1 to 8, wherein the glass has a formed joining surface.   The phase separation glass according to claim 1, wherein the phase separation glass is used for organic EL lighting.   An organic EL device comprising the phase-separated glass according to claim 1.