WO2016117406A1 - Phase-separated glass - Google Patents

Abstract

The present invention addresses the technical problem of providing a glass with which excellent productivity is achieved, and which is capable of improving light extraction efficiency of an organic EL element, even if a light extraction layer comprising a sintered body is not formed. This phase-separated glass is characterized by: being provided with a phase-separated structure including at least a first phase and a second phase; having a refractive index (n_d) of at least 1.51; and having a liquid-phase viscosity of at least 10^3.5 dPa∙s.

Description

Phase separation glass

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

In recent years, the 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.

The light source for illumination is divided into a “directional light source” that illuminates a limited area and a “diffuse light source” that illuminates a wide area. 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 exhibiting electroluminescence that emits light by current injection, and a cathode, and a cathode. It is an 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 are being 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 luminous efficiency is necessary.

JP 2012-25634 A

One cause of the decrease in luminance is that light is confined in the glass plate due to the difference in refractive index between the glass plate and air. For example, when a glass plate having a refractive index n _{d of} 1.50 is used, since the refractive index n _{d of} air is 1.0, the critical angle is calculated to be 42 ° from Snell's law. Therefore, light having an incident angle greater than the critical angle causes total reflection, is confined in the glass plate, and is not extracted into the air.

In order to solve the above problems, 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 a glass frit having a high refractive index is sintered is formed on the surface of a soda glass plate, and a scattering substance is dispersed in the light extraction layer, thereby reducing the light extraction efficiency. It is also described to increase.

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 the technical problem thereof is that the light extraction efficiency of the organic EL element can be increased without producing a light extraction layer made of a sintered body, and the production can be achieved. The idea is to create an excellent glass.

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 refractive index and devitrification resistance of the phase separation glass within a predetermined range. It is proposed as the present invention. That is, phase-separated glass of the present invention, i.e., phase-separated glass of the present invention has a phase separation structure comprising at least a first phase and a second phase, the refractive index n _d be 1.51 or more In addition, the liquid phase viscosity is 10 ^3.5 dPa · s or more. Here, “refractive index n _d ” 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 is first prepared, and is slowly cooled at a cooling rate of 0.1 ° C./min in the temperature range from (annealing point Ta + 30 ° C.) to (strain point Ps−50 ° C.). after, while penetration of immersion the refractive index n _d are aligned, it can be measured by the refractive index measuring instrument KPR-2000 manufactured by Shimadzu Corporation. “Liquid phase viscosity” refers to the viscosity of the glass at the liquidus temperature. “Liquid phase temperature” is a glass powder that passes through 30 mesh (a sieve opening of 500 μm) and remains in a 50 mesh (a sieve opening of 300 μm) in a platinum boat and is kept in a temperature gradient furnace for 24 hours. The value which measured the temperature which precipitates. Note that the phase separation structure including at least the first phase and the second phase can be visually confirmed by light scattering on the surface.

The phase separation glass of the present invention has a phase separation structure including at least a first phase and a second phase. In this way, when applied to an organic EL device, 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 the light can be easily taken out to the outside. As a result, the light extraction efficiency can be increased without forming a light extraction layer made of a sintered body.

Phase-separated glass of the present invention, the refractive index _{n d} is 1.51 or more. 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 _{n d} of the transparent conductive film is 1.9 to 2.0, and the refractive index _{n d} of the organic EL layer was 1.8-1.9. In contrast, the refractive index _{n d} of the glass plate was typically about 1.50. Therefore, if the refractive index _nd is regulated as described above, the difference in refractive index between the glass plate and the transparent conductive film is reduced, so that light incident from the organic EL layer is reflected at the interface between the glass plate and the transparent conductive film. Light extraction efficiency can be increased.

The phase separation glass of the present invention has a liquidus viscosity of 10 ^3.5 dPa · s or more. Since the conventional high refractive index phase-separated glass has a low liquidus viscosity, it has been difficult to produce a large number of glass plates. Therefore, if the liquidus viscosity is regulated as described above, the glass becomes difficult to devitrify at the time of molding, and in particular, it becomes easy to mass-produce a plate-shaped phase-separated glass. As a result, the manufacturing cost of the phase separation glass can be reduced.

Secondly, phase-separated glass of the present invention preferably has a refractive index n _d is less than 1.63.

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

Fourth, the phase-separated glass of the present invention preferably has a content of SiO ₂ + Al ₂ O ₃ + B ₂ O _{3 in} the glass composition of 55 to 80% by mass. If it does in this way, devitrification resistance can further be improved. Here, “SiO ₂ + Al ₂ O ₃ + B ₂ O ₃ ” refers to the total amount of SiO ₂ , Al ₂ O ₃ and B ₂ O ₃ .

Fifth, the phase-separated glass of the present invention preferably has a content of MgO + CaO + SrO + BaO + ZnO in the glass composition of 15 to 35% by mass. Here, “MgO + CaO + SrO + BaO + ZnO” refers to the total amount of MgO, CaO, SrO, BaO and ZnO.

Sixth, the phase-separated glass of the present invention preferably has a P ₂ O ₅ content of 0.001 to 20% by mass in the glass composition. In this way, it becomes easy to improve the phase separation.

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

Eighth, it is preferable that the phase separation glass of the present invention has a flat plate shape.

Ninth, the phase separation glass of the present invention is preferably formed by an overflow downdraw method.

Tenth, the phase separation glass of the present invention is preferably used for illumination.

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

Twelfth, it is preferable that the organic EL device of the present invention includes the above phase separation glass.

Phase-separated glass of the present invention has a phase separation structure comprising at least a first phase and a second phase, the content of SiO ₂ in the first phase, containing SiO ₂ in the second phase More than the amount is preferred. 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 glass can be improved. In addition, if the surface of the sample after being immersed in a 2% by volume hydrofluoric acid solution for 2 minutes is observed with a field emission scanning electron microscope, the details of each phase, particularly the content of SiO ₂ in each phase can be confirmed. is there.

In the phase-separated glass of the present invention, the average particle size of phase-separated particles of at least one phase (first phase and / or second phase) is preferably 0.01 to 5 μm, particularly preferably 0.02 to 1 μm. If the average particle size of the phase-separated particles is small, the light emitted from the organic EL layer is difficult to scatter at the interface between the first phase and the second phase. On the other hand, if the average particle size of the phase-separated particles is large, the scattering intensity becomes too strong and the total light transmittance may be lowered.

In phase-separated glass of the present invention, the refractive index _{n d} is 1.51 or more, preferably 1.52 or more, 1.53 or more, 1.54 or more, particularly 1.55 or more. When the refractive index n _d is less than 1.51, it becomes difficult to efficiently extract light by reflection at the interface, such as a glass plate and a transparent conductive film. On the other hand, if the refractive index n _d is too high, since the introduction of the components to improve the devitrification resistance is limited, it is difficult to increase the liquidus viscosity. Further, the reflectance at the interface between the glass plate and the air becomes high, and it becomes difficult to extract light to the outside. Therefore, the refractive index _{n d} is preferably 2.30 or less, 2.00 or less, 1.80 or less, 1.70 or less, 1.65 or less, less than 1.63, 1.62 or less, 1.61 or less, 1.60 or less, 1.59 or less, particularly 1.58 or less.

In the phase separation glass of the present invention, the liquidus viscosity is 10 ^3.5 dPa · s or more, preferably 10 ^3.5 dPa · s or more, 10 ^3.8 dPa · s or more, 10 ^4.0 dPa · s. Above, 10 ^4.2 dPa · s or more, 10 ^4.4 dPa · s or more, 10 ^4.6 dPa · s or more, particularly 10 ^4.8 dPa · s or more. When the liquidus viscosity is low, the devitrification resistance is lowered, and it becomes difficult to form a glass plate by an overflow down draw method, a float method or the like.

Phase-separated glass of the present invention has a glass composition, in _{mass%, SiO 2 30 ~ 75%} , Al 2 O 3 0 ~ 35%, preferably contains 2 O 3 0.1 ~ 50% B . 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, the preferable lower limit range of SiO ₂ is 30% or more, 35% or more, 40% or more, 42% or more, 44% or more, particularly 46% 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 0.1% or more, 3% or more, 4% or more, particularly 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 content of SiO ₂ + Al ₂ O ₃ + B ₂ O ₃ is preferably 55 to 80%, 58 to 75%, 60 to 70%, particularly 64 to 68% from the viewpoint of refractive index and devitrification resistance. .

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 content of Li ₂ O + Na ₂ O + K ₂ O is too large, the liquid phase viscosity decreases. It becomes easy and a strain point falls easily. Furthermore, the alkali component is easily eluted in the acid etching step. Therefore, a suitable upper limit range of Li ₂ O + Na ₂ O + K 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%.

Li ₂ O is a component that enhances phase separation. However, if the content of Li ₂ O is too large, the liquid phase 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 Li 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%.

Na ₂ O is a component that lowers the high temperature viscosity. However, if the content of Na ₂ O is too large, the liquid phase viscosity tends to decrease and the strain point tends to decrease. Furthermore, the alkali component is easily eluted in the acid etching step. Therefore, 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%.

K ₂ O is a component that enhances phase separation. However, if the content of K ₂ O is too large, the liquid phase 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 K 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%.

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, when introducing MgO, a suitable lower limit range is 0% or more, 0.1% or more, 0.2% or more, especially 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 the glass composition component is impaired, and the 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.

When the content of SrO is increased, the refractive index and the density are likely to be increased, and the balance of components of the glass composition is impaired, and 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 10% 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 content of ZnO increases, the refractive index tends to increase, but the density tends to increase, and the balance of 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 content of MgO + CaO + SrO + BaO + ZnO is preferably 15 to 35%, 20 to 34%, 22 to 33%, 24 to 32%, particularly 26 to 31% from the viewpoint of achieving both refractive index and devitrification resistance. The mass ratio (SiO ₂ + Al ₂ O ₃ + B ₂ O ₃ ) / (MgO + CaO + SrO + BaO + ZnO) is preferably 1.8 to 4.0, 2.0 to 3.3 from the viewpoint of achieving both refractive index and devitrification resistance. 2, 2.1 to 3.0, 2.2 to 2.9, particularly 2.3 to 2.8. Here, “(SiO ₂ + Al ₂ O ₃ + B ₂ O ₃ ) / (MgO + CaO + SrO + BaO + ZnO)” is a value obtained by dividing the content of SiO ₂ + Al ₂ O ₃ + B ₂ O _{3 by} the content of MgO + CaO + SrO + BaO + ZnO.

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, the preferable upper limit range of TiO ₂ is 20% or less, 15% or less, 10% or less, 5% or less, particularly 3% or less, and the preferable lower limit range is 0% or more, 0.001% or more, 0. 01% or more, 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 is a component that increases the refractive index. However, when the content of La ₂ O ₃ increases, the density tends to increase, and devitrification resistance and acid resistance easily decrease. Furthermore, the raw material cost rises, and the manufacturing cost of the glass plate is likely to rise. Therefore, a suitable upper limit range of La ₂ O ₃ is 10% or less, 5% or less, 3% or less, 1% or less, 0.5% or less, particularly 0.1% or less.

Nb ₂ O ₅ is a component that increases the refractive index, but as the content of Nb ₂ O ₅ increases, the density tends to increase and the devitrification resistance tends to decrease. Furthermore, the raw material cost rises, and the manufacturing cost of the glass plate is likely to rise. Therefore, the preferable upper limit range of Nb ₂ O ₅ is 10% or less, 5% or less, 3% or less, 1% or less, 0.5% or less, particularly 0.1% or less.

Gd ₂ O ₃ is a component that increases the refractive index. However, if the content of Gd ₂ O ₃ increases, the density becomes too high, or the balance of the glass composition component is lost, resulting in a decrease in devitrification resistance. The high-temperature viscosity is too low, and it becomes difficult to ensure a high liquid phase viscosity. Therefore, a suitable upper limit range of Gd ₂ O ₃ is 10% or less, 5% or less, 3% or less, 1% or less, 0.5% or less, particularly 0.1% 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. Up to 3% 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 viewpoint, and the content of each is preferably less than 0.3%, particularly preferably less than 0.1%. 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, and particularly 0.001 to 0.02%.

The CeO ₂ content 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 6% or less, 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 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 liquidus temperature is preferably 1200 ° C. or lower, 1150 ° C. or lower, 1100 ° C. or lower, particularly 1060 ° C. or lower. If it does in this way, it will become difficult to devitrify glass at the time of shaping | molding, for example, will become easy to shape | mold a glass plate by the overflow downdraw method, the float glass method, etc.

The phase separation temperature is preferably 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. The 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, particularly 10 ^3.5 to 10 ^6.0 dPa · s. is there. If it does in this way, it will become easy to phase-separate glass by a formation process and / or a slow cooling process, and it will become easy to shape | mold a glass plate which has a phase-separation structure by the overflow downdraw method, the float glass method, etc. As a result, after forming the glass plate, a separate heat treatment step for phase separation of the glass becomes unnecessary, and the manufacturing cost of the glass plate can be easily reduced. 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 glass is preferably phase-separated in the forming step and / or the slow cooling step, but the glass may be phase-separated other than these steps, for example, in the melting step.

The thickness (in the case of a flat plate) is preferably 1.5 mm or less, 1.3 mm or less, 1.1 mm or less, 0.8 mm or less, 0.7 mm or less, 0.5 mm or less, 0.3 mm or less, 0 .2 mm or less, particularly 0.1 mm or less. The smaller the thickness, the higher the flexibility and the easier it is to improve the design of organic EL lighting. However, when the thickness is extremely small, the glass tends to break. Therefore, the thickness is preferably 10 μm or more, particularly 30 μm or more.

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 (especially an 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-separated 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.

Other than the above molding method, for example, a redraw method, a float method, a roll-out method, etc. can be employed. In particular, in the float process, a large glass plate can be efficiently formed.

The phase-separated glass of the present invention is preferably not subjected to a heat treatment step for phase-separating the glass after the cutting step, and the glass is phase-separated in the molding step, or a slow cooling (cooling) step immediately after molding. It is preferable that the glass is phase-separated. In particular, when a glass plate is formed by the overflow downdraw method, a phase separation phenomenon may occur in the bowl-shaped structure, or a phase separation phenomenon may occur during stretch molding or slow cooling. If it does in this way, the number of manufacturing processes will decrease and the productivity of phase separation glass can be raised. The phase separation phenomenon can be controlled by the glass composition, molding conditions, slow cooling conditions, and the like.

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 HF etching, sandblasting, or the like. Moreover, you may form an uneven | corrugated shape in the surface of a glass plate by heat processing, such as a repress. In this way, an accurate non-reflective structure can be formed on the glass surface. Uneven shape, taking into account the refractive index n _d, may be adjusted the spacing and depth.

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 HF gas is generated, the roughened surface can be formed efficiently.

Furthermore, a roughened surface can be formed on at least one surface during 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.

Hereinafter, the present invention will be described in detail based on examples. The following examples are merely illustrative. The present invention is not limited to the following examples.

Tables 1 to 3 show sample numbers. 1 to 32 are shown.

[Supplement under rule 26 01.02.2016]

[Supplement under rule 26 01.02.2016]

[Supplement under rule 26 01.02.2016]

First, after preparing glass raw materials so as to have the glass compositions shown in Tables 1 to 3, the obtained glass batch was supplied to a glass melting furnace and melted at 1400 ° C. for 7 hours. Next, after the obtained molten glass was poured on a carbon plate and formed into a flat plate shape, a slow cooling treatment was performed from the strain point to room temperature over 10 hours. Finally, the obtained glass plate was processed as necessary to evaluate various properties. The obtained glass plate has a phase separation structure including at least a first phase and a second phase, that is, exhibits phase separation, and the sample surface after being immersed in a 2% by volume hydrofluoric acid solution for 2 minutes. Was observed with a field emission scanning electron microscope. As a result, the content of SiO ₂ in the first phase was higher than the content of SiO ₂ in the second phase.

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

Refractive index _{n d} is the value of the d-line as determined by the 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 infiltrating an immersion liquid having a matching refractive index n _d after annealing.

As can be seen from Tables 1 to 3, Sample No. 1 to 32 have a phase separation structure including at least a first phase and a second phase, a liquid phase viscosity of 10 ^3.5 dPa · s or more, and a refractive index nd of 1.550 or more. there were. Therefore, sample no. Nos. 1 to 32 can be suitably used as glass plates used for organic EL lighting.

Claims (12)

1. Having a phase separation structure including at least a first phase and a second phase;
   Refractive index _{n d} is not less 1.51 or more,
   And a liquid phase viscosity of 10 ^3.5 dPa · s or more.
2. Phase-separated glass of claim 1 having a refractive index n _d is equal to or less than 1.63.
3. _{3. The} glass composition according to claim 1, wherein the glass composition contains SiO ₂ 30 to 75%, Al ₂ O ₃ 0 to 35%, and B ₂ O ₃ 0.1 to 50% by mass. The phase separation glass described in 1.
4. 4. The phase-separated glass according to claim 1, wherein the content of SiO ₂ + Al ₂ O ₃ + B ₂ O _{3 in} the glass composition is 55 to 80% by mass.
5. 5. The phase-separated glass according to claim 1, wherein the content of MgO + CaO + SrO + BaO + ZnO in the glass composition is 15 to 35% by mass.
6. 6. The phase-separated glass according to claim 1, wherein the content of P ₂ O ₅ in the glass composition is 0.001 to 20% by mass.
7. 7. The phase-separated glass according to claim 1, wherein the content of Li ₂ O + Na ₂ O + K ₂ O in the glass composition is 5% by mass or less.
8. The phase-separated glass according to any one of claims 1 to 7, which has a flat plate shape.
9. The phase-separated glass according to any one of claims 1 to 8, which is formed by an overflow downdraw method.
10. 10. The phase separation glass according to claim 1, which is used for illumination.
11. 11. The phase separation glass according to claim 1, which is used for organic EL lighting.
12. An organic EL device comprising the phase-separated glass according to any one of claims 1 to 11.