KR102265027B1 - High refractive index glass - Google Patents

Abstract

The high refractive index glass of the present invention contains MgO+CaO+SrO+BaO+ZnO 25-60%, CaO 0-5%, TiO ₂ +ZrO ₂ 3-20% by mass% as a glass composition, and the refractive index (n _d ) is 1.55-1.70 do it with

Description

High refractive index glass {HIGH REFRACTIVE INDEX GLASS}

The present invention relates to high refractive index glass, for example high refractive index glass suitable for organic EL devices, in particular organic EL lighting.

BACKGROUND ART In recent years, displays and lighting using organic EL light emitting devices have been increasingly attracting attention. These organic EL devices have a structure in which an organic light emitting element is sandwiched by a glass plate on which a transparent conductive film such as ITO is formed. In this structure, when an electric current flows through the organic light emitting element, holes and electrons in the organic light emitting element associate and emit light. The emitted light enters the glass plate through a transparent conductive film such as ITO, and is emitted to the outside while repeating reflection within the glass plate.

Japanese Patent Laid-Open No. 2007-186407

By the way, the refractive index (n _d ) of the organic light emitting device is 1.8 to 1.9, and the refractive index (n _d ) of ITO is 1.9 to 2.0. On the other hand, the refractive index ( _nd ) of a glass plate is about 1.5 normally. For this reason, since the conventional organic electroluminescent device originates in the refractive index difference of a glass plate-ITO interface, and has high reflectance, there existed a problem that the light which generate|occur|produced from an organic light emitting element could not be taken out efficiently.

Moreover, in the field of optical glass, glass of a high refractive index may be used (for example, refer patent document 1). However, these glasses contain a large amount of expensive heavy metals, and since they have low liquidus viscosity, they are difficult to be molded into a flat plate shape and are not suitable for mass production.

Therefore, the present invention has been made in view of the above circumstances, and its technical object is to create a high refractive index glass having a high liquidus viscosity even if it does not contain a large amount of expensive heavy metals.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining, the present inventors discover that the said technical problem can be solved by regulating a glass composition range and a glass characteristic to predetermined range, and propose as the following 1st - 4th invention.

That is, the high refractive index glass according to the first invention contains MgO + CaO + SrO + BaO + ZnO 25 to 60%, CaO 0 to 5%, TiO ₂ +ZrO ₂ 3 to 20% by mass% as a glass composition, and the refractive index (n _d ) is 1.51 to It is characterized as 2.0. Here, "MgO+CaO+SrO+BaO+ZnO" is the total amount of MgO, CaO, SrO, BaO, and ZnO. "TiO ₂ + ZrO _2" is the total amount of TiO ₂ and ZrO _2. The "refractive index (n _d )" is a measured value on the d line (wavelength 587.6 nm) of a hydrogen lamp, and can be measured with a refractive index measuring device. For example, after producing a rectangular parallelepiped sample of 25 mm x 25 mm x about 3 mm, the temperature range from (slow cooling point + 30 °C) to (strain point - 50 °C) is annealed at a cooling rate of 0.1 °C/min. Then, it can measure by using the refractometer KPR-2000 manufactured by Shimadzu Corporation while permeating the immersion liquid whose refractive index is matched between the glasses.

In addition, the high refractive index glass according to the second invention is a glass composition in mass %: SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ 30 to 80%, B ₂ O ₃ +ZnO 0.1 to 20%, TiO ₂ +ZrO ₂ 3 to 20% It contains, and also the refractive index (n _d ) is characterized in that 1.51 ~ 2.0. Here, _{"SiO 2 + Al 2 O 3 +} B 2 O 3 " is the total amount of SiO _2, Al ₂ O ₃ and B ₂ O _3. "B ₂ O ₃ +ZnO" is the total amount of _{B 2} O _{3 and ZnO.} "TiO ₂ + ZrO _2" is the total amount of TiO ₂ and ZrO _2. The "refractive index (n _d )" is the same as described in the first invention.

Further, the high refractive index glass according to the third invention contains _{3 to 20 mass% of TiO 2} +ZrO ₂ as a glass composition, the mass ratio (MgO + CaO + SrO + BaO + ZnO) / CaO is 2 to 10, the refractive index (n _d ) is 1.51 to 2.0 characterized. Here, "TiO ₂ + ZrO _2" is the total amount of TiO ₂ and ZrO _2. "MgO+CaO+SrO+BaO+ZnO" is the total amount of MgO, CaO, SrO, BaO, and ZnO. "(MgO+CaO+SrO+BaO+ZnO)/CaO" points out the value obtained by dividing the content of MgO+CaO+SrO+BaO+ZnO by the content of CaO. The "refractive index (n _d )" is the same as described in the first invention.

The high refractive index glass according to the fourth invention has a glass composition, in terms of mass%, of SiO ₂ 26-70%, B ₂ O ₃ 4.5-35%, MgO+CaO+SrO+BaO+ZnO 10-48%, BaO 10-31%, Li ₂ O+Na ₂ O+K ₂ O It contains 0 to 0.29%, and also the refractive index (n _d ) is characterized as 1.51 to 2.0. Here, "MgO+CaO+SrO+BaO+ZnO" is the total amount of MgO, CaO, SrO, BaO, and ZnO. _{"Li 2 O + Na 2 O +} K 2 O " is the total amount of Li ₂ O, Na ₂ O and K ₂ O. The "refractive index (n _d )" is the same as described in the first invention.

It is preferable that the high refractive index glass by 3rd invention contains more than 5.0 mass % of CaO. In this way, after maintaining the refractive index, it is easy to increase the meltability and the Young's modulus.

The first to the high refractive index glass according to the third invention preferably comprises a B ₂ O ₃ 0.1 ~ 15% by weight. In this way, it becomes easy to reduce a density and liquidus temperature.

The first to the high refractive index glass according to the fourth invention preferably includes a ZrO ₂ 0.01 ~ 10% by weight. In this way, the liquidus viscosity can be increased by increasing the temperature near the liquidus temperature while increasing the refractive index.

The first to the high refractive index glass according to the fourth invention preferably comprises a TiO ₂ 0.01 ~ 15% by weight. In this way, the refractive index can be increased.

The high refractive index glass according to the first to fourth inventions contains substantially no PbO, and the content of Bi ₂ O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +Nb ₂ O ₅ +Ta ₂ O ₅ +WO ₃ is 9% by mass or less. it is preferable In this way, it is possible to reduce the batch cost while considering the environmental requirements. Here, "substantially free from" means that the content of the specified component is avoided as much as possible, but the incorporation of the impurity level is permitted, and specifically, the content of the specified component is less than 0.5% (preferably 0.1%). less than) is indicated.

It is preferable that the high refractive index glass by 1st - 4th invention contains 0.1-15 mass % of ZnO. This makes it easy to lower the liquidus temperature.

It is preferable that the high refractive index glass by 1st - 4th invention does not contain an alkali metal oxide substantially. This may jeoryeomhwa the production cost becomes unnecessary to form a passivation film such as a SiO ₂ film. Here, "alkali metal oxides" include Li ₂ O, Na ₂ O and K ₂ O.

The first to the high refractive index glass according to the fourth invention is preferably at least the liquid viscosity 10 ^{3. 0} dPa · s. In this way, it becomes easy to shape|mold a glass plate by the overflow down-draw method. Here, "liquid phase viscosity" points out the value which measured the viscosity of the glass in liquidus temperature by the platinum ball pulling-up method. "Liquid temperature" is a value measured at the temperature at which crystals are precipitated by passing through a standard sieve 30 mesh (500 μm), putting the glass powder remaining in 50 mesh (300 μm) in a platinum boat, and holding it in a temperature gradient furnace for 24 hours. .

It is preferable that the high-refractive-index glass by 1st - 4th invention is flat plate shape, and that the surface roughness (Ra) of at least one surface is 10 angstroms or less. Here, "surface roughness (Ra)" points out the value measured by the method based on JISB0601:2001.

It is preferable that the high-refractive-index glass by 1st - 4th invention is formed by the overflow down-draw method.

The high refractive index glass by the above 1st - 4th invention can be used for a lighting device, organic electroluminescent illumination, and organic electroluminescent display.

<First invention>

The high refractive index glass according to the first invention will contain 25 ~ 60% MgO + CaO + SrO + BaO + ZnO as a glass composition, CaO 0 ~ 5%, TiO 2 + ZrO 2 3 ~ 20%. The reason for limiting the content range of each component in this way is demonstrated below. In addition, in the description of the following content range, % indication represents mass %, except when there is a special mention.

The content of MgO+CaO+SrO+BaO+ZnO is 25 to 60%, preferably 30 to 55%, 32 to 50%, 34 to 49%, 36 to 47%, and particularly 38 to 45%. In this way, high refractive index, devitrification resistance, meltability, low density, and low coefficient of thermal expansion can be simultaneously achieved at high levels. Moreover, when there is too much content of MgO+CaO+SrO+BaO+ZnO, there exists a possibility that a density and a thermal expansion coefficient may rise unreasonably, and when content of MgO+CaO+SrO+BaO+ZnO is too small, refractive index, devitrification resistance, and meltability fall easily.

When content of MgO+CaO increases, the balance of a glass composition will be lost and devitrification resistance will fall easily. Therefore, the content of MgO+CaO is preferably 12% or less, 10% or less, 8% or less, 7% or less, 6% or less, 4.6% or less, 4% or less, 3.5% or less, 3% or less, particularly 2.5% or less. . Moreover, when content of MgO+CaO decreases, meltability will fall easily. Therefore, the content of MgO+CaO is preferably 0.1% or more, 0.5% or more, 1% or more, and particularly 2% or more. Here, "MgO+CaO" is the total amount of MgO and CaO.

MgO is a component that increases the Young's modulus and lowers the high-temperature viscosity, but when MgO is contained in a large amount, the refractive index tends to decrease, liquidus temperature rises and devitrification resistance tends to decrease, and density and coefficient of thermal expansion tend to increase . Therefore, the content of MgO is preferably 10% or less, 5% or less, 3% or less, 2% or less, 1.5% or less, 1% or less, particularly 0.5% or less.

The content of CaO is 0 to 5%. When content of CaO increases, a density and a thermal expansion coefficient will become high easily, and when the content exceeds 5 %, balance of a glass composition will be lost and devitrification resistance will fall easily. Accordingly, the content of CaO is preferably 4.5% or less, 4% or less, 3.5% or less, 3% or less, particularly 2.5% or less. Moreover, when content of CaO decreases, refractive index, meltability, and Young's modulus will fall easily. Therefore, the content of CaO is preferably 0.1% or more, 0.5% or more, 1% or more, particularly 2% or more.

The mass ratio (MgO+CaO+SrO+BaO+ZnO)/CaO is preferably 8.5 or more, 10 or more, 11.4 or more, 12 or more, 13-25, 13.5-21, 14-19, especially 14.5-17. In this way, it becomes easy to raise refractive index and devitrification resistance simultaneously. In addition, "(MgO+CaO+SrO+BaO+ZnO)/CaO" points out the value obtained by dividing the content of MgO+CaO+SrO+BaO+ZnO by the content of CaO.

When the content of SrO increases, the refractive index increases and it becomes possible to increase the viscosity near the liquidus temperature, but the density and the coefficient of thermal expansion tend to be high. Moreover, when content of SrO becomes excess, the balance of a glass composition will be lost and devitrification resistance will fall easily. Therefore, the content of SrO is preferably 20% or less, 15% or less, 13% or less, 12% or less, particularly 11% or less. Moreover, when content of SrO decreases, refractive index and meltability will fall easily. Therefore, the content of SrO is preferably 0.1% or more, 1% or more, 3% or more, 5% or more, 7% or more, 8% or more, particularly 10% or more.

BaO is a component which does not reduce the viscosity of glass extremely in an alkaline-earth metal oxide, but raises refractive index. However, when the content of BaO increases, the density and the coefficient of thermal expansion tend to increase, and the liquidus viscosity tends to decrease. Moreover, when there is too much content of BaO, the balance of a glass composition will be lost and devitrification resistance will fall easily. Therefore, the content of BaO is preferably 50% or less, 45% or less, 40% or less, 35% or less, 32% or less, 30% or less, particularly 28% or less. However, when content of BaO decreases, it will become difficult to obtain a desired refractive index, and it will become difficult to ensure high liquidus viscosity. Therefore, the content of BaO is preferably 0.1% or more, 1% or more, 5% or more, 10% or more, 12% or more, 15% or more, 17% or more, 20% or more, 23% or more, especially 25% or more. .

When the content of ZnO increases, the density and the coefficient of thermal expansion increase, the component balance of the glass composition is lost, the devitrification resistance decreases, or the high temperature viscosity decreases excessively, making it difficult to secure a high liquidus viscosity. Accordingly, the content of ZnO is preferably 15% or less, 10% or less, 6% or less, 4% or less, 2% or less, 1% or less, 0.5% or less, particularly 0.1% or less. However, when the content of ZnO decreases, it becomes difficult to ensure a high liquidus viscosity. Therefore, the content of ZnO is preferably 0.1% or more, 0.5% or more, 1% or more, 1% or more, 1.5% or more, 2% or more, 2.5% or more, especially 3% or more.

TiO ₂ + ZrO ₂ does not advance the batch cost, it is a component to increase the refractive index effectively. However, when the content of TiO ₂ + ZrO ₂ is apt to substantial increases, covered with reduced. Therefore, _{the content of TiO 2} +ZrO ₂ is 3 to 20%, preferably 4 to 15%, 5 to 12%, 5.5 to 11%, 6 to 10%, and particularly 6.5 to 9%. Further, the Zr-containing devitrification when you want to suppress the generation of water, TiO ₂ + content of ZrO ₂ is preferably 7.5% or less, 7% or less, 6.5% or less, particularly 6% or less.

TiO ₂ is a component that effectively increases the refractive index without increasing the collective cost. However, when the content of TiO ₂ increases, or the glass tends to be colored is covered with substantial degradation. Therefore, _{the content of TiO 2} is preferably 0.01 to 15%, 0.1 to 15%, 1 to 12%, 2 to 11%, 3 to 10%, 4 to 9%, and particularly 5 to 8%. In addition, when the content of TiO ₂ increases, is liable to promote the Zr-containing water generated devitrification. Therefore, when it is desired to suppress the generation of Zr-containing devitrification, _{the content of TiO 2} is preferably 6% or less, 5.5% or less, 5% or less, 4.5% or less, and particularly 4% or less.

ZrO ₂ is a component that effectively raises the refractive index without raising the batch cost. However, when the content of ZrO ₂ be easily increases, the liquidus temperature decreases. Therefore, _{the content of ZrO 2} is preferably 0 to 10%, 0.01 to 10%, 0.5 to 8%, 1 to 7%, 1.5 to 6.5%, 2.5 to 6%, particularly 3 to 5.5%. In addition, when it is desired to suppress the generation of Zr-containing devitrification, _{the content of ZrO 2} is preferably 5% or less, 4% or less, 3.5% or less, 3% or less, and particularly 2.5% or less.

In addition to the above components, for example, the following components may be added.

The content of _{SiO 2 + Al 2 O 3 +} B 2 O 3 is 30 to 80% is preferred. The vitrification becomes difficult when the content of _{SiO 2 + Al 2 O 3 +} B 2 O 3 becomes less difficult to form when the glass mangnun structure. Moreover, the viscosity of glass falls too much and it becomes difficult to ensure high liquidus viscosity. Therefore, _{the content of SiO 2} +Al ₂ O ₃ +B ₂ O ₃ is preferably 30% or more, 35% or more, 38% or more, 40% or more, 42% or more, 45% or more, 47% or more, 49% or more, Especially more than 50%. On the other hand, when the content of _{SiO 2 + Al 2 O 3 +} B 2 O 3 is apt to be increases, the melting property, the moldability is lowered, and the refractive index is apt to decrease. Therefore, _{the content of SiO 2} +Al ₂ O ₃ +B ₂ O ₃ is preferably 80% or less, 75% or less, 70% or less, 65% or less, 60% or less, 57% or less, particularly 55% or less. Further, _{"SiO 2 + Al 2 O 3 +} B 2 O 3 " is the total amount of SiO _2, Al ₂ O ₃ and B ₂ O _3.

Mass ratio of _{(SrO + BaO + TiO 2 +} ZrO 2) / (SiO 2 + Al 2 O 3 + B 2 O 3) is 0.1 to 3 are preferred. Mass ratio of _{(SrO + BaO + TiO 2 +} ZrO 2) / (SiO 2 + Al 2 O 3 + B 2 O 3) , the smaller the surface difficult to increase the refractive index. Thus, the weight ratio of (SrO + BaO + TiO2 + ZrO 2) / (SiO 2 + Al 2 O 3 + B 2 O 3) the lower limit of preferably 0.1, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, especially 0.9. On the other hand, when the mass ratio (SrO+BaO+TiO ₂ +ZrO ₂ )/(SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ ) becomes large, vitrification becomes difficult, and the viscosity of the glass is extremely reduced, making it difficult to ensure high liquidus viscosity. Therefore, the upper limit of the mass ratio (SrO+BaO+TiO ₂ +ZrO ₂ )/(SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ ) is preferably 3, 2, 1.5, 1.3, 1.1, particularly 1. Further, _{"SrO + BaO + TiO 2 + ZrO} 2 " is the total amount of SrO, BaO, TiO ₂ and ZrO _2.

The content of SiO ₂ is a 30 to 70% is preferred. The vitrification becomes difficult when the content of SiO ₂ down when it becomes difficult to form the glass mangnun structure. Moreover, the viscosity of glass falls too much and it becomes difficult to ensure high liquidus viscosity. Therefore, _{the content of SiO 2} is preferably 30% or more, 33% or more, 35% or more, 37% or more, 38% or more, 39% or more, and particularly 40% or more. On the other hand, when the content of SiO ₂ is more liable to surface refractive index, melting property, the moldability is lowered. Therefore, _{the content of SiO 2} is preferably 70% or less, 65% or less, 60% or less, 55% or less, 53% or less, 51% or less, 50% or less, 48% or less, 45% or less, 43% or less, In particular, it is below 41%.

The content of Al ₂ O ₃ is preferably 0 to 20%. If the content of Al ₂ O ₃ increases, devitrification is likely to crystals were precipitated in the glass becomes liable to liquid viscosity is reduced, and the refractive index is apt to decrease. Accordingly, _{the content of Al 2} O ₃ is preferably 20% or less, 15% or less, 10% or less, 8% or less, particularly 6% or less. Also, note the content of Al ₂ O ₃ When the lost balance of the glass composition be easily opposed to glass devitrification. Therefore, _{the content of Al 2} O ₃ is preferably 0.1% or more, 0.5% or more, 1% or more, 3% or more, 4% or more, particularly 5% or more.

The mass ratio CaO/Al ₂ O ₃ is preferably 1.15 or less, 1.1 or less, 1 or less, 0.9 or less, 0.1 to 0.8, 0.2 to 0.7, 0.3 to 0.65, and particularly 0.4 to 0.6. In this way, devitrification resistance improves and it becomes easy to shape|mold a glass plate by the overflow down-draw method. In addition, "CaO / Al ₂ O _3" refers to a value obtained by dividing the content of CaO in a content of Al ₂ O _3.

The content of B ₂ O ₃ is preferably 0 to 15%. If the content of B ₂ O ₃ is more liable to surface refraction index, and the Young's modulus is reduced. Therefore, _{the content of B 2} O ₃ is preferably 15% or less, 13% or less, 12% or less, 10% or less, 8% or less, particularly 6% or less. Also, note the content of B ₂ O ₃ when the liquid is apt to drop in temperature. Therefore, _{the content of B 2} O ₃ is preferably 0.1% or more, 1% or more, 2% or more, 3% or more, 4% or more, and particularly 5% or more.

A mass ratio _{(B 2 O3 + MgO) /} CaO is preferably 1 or higher, 1.3 or higher, 1.5 or higher, 1.6 or higher, 1.65 to 5, 1.7 to 4.5 and 1.8 to 4, 1.9 to 3.5, in particular 2-3. In this way, since it becomes easy to make it compatible with devitrification resistance and meltability, it becomes easy to raise the manufacturing efficiency of a glass plate. Further, "(B ₂ O ₃ + MgO) / CaO" refers to a value obtained by dividing the total amount of B ₂ O ₃ and MgO in a content of CaO.

Mass ratio of B ₂ O ₃ / TiO ₂ is preferably 0.1 to 50, 0.3 to 30, 0.5 to 20, 0.7 to 10, 0.8 to 5, 0.9 to 4, especially 1-3. In this way, devitrification resistance improves and it becomes easy to shape|mold a glass plate by the overflow down-draw method. Further, "B ₂ O ₃ / TiO _2" indicates a value obtained by dividing the content of B ₂ O ₃ in a content of TiO _2.

Alkali metal oxide is a component which reduces the viscosity of glass, and is a component which adjusts a thermal expansion coefficient. However, when it flows in a large amount, the viscosity of glass falls too much and it becomes difficult to ensure high liquidus viscosity. In addition, it is therefore necessary to use a passivation film such as a SiO ₂ film formed on the surface of the glass. Therefore, the content of the alkali metal oxide is preferably 15% or less, 10% or less, 5% or less, 2% or less, 1% or less, particularly 0.5% or less, and it is preferable not to contain substantially. In addition, _{the content of Li 2} O, Na ₂ O, and K ₂ O is preferably 10% or less, 8% or less, 5% or less, 2% or less, 1% or less, particularly 0.5% or less, respectively, and substantially no it is preferable

As a clarifier, As ₂ O ₃ , Sb ₂ O ₃ , CeO ₂ , SnO ₂ , F, Cl, SO ₃ One or more selected from the group consisting of 0 to 3% may be added. However, As ₂ O ₃ and F, in particular As ₂ O ₃ is preferably substantially free from the environmental point of view. In particular, Sb ₂ O ₃ , SnO ₂ , SO ₃ and Cl are preferable as the clarifier. The content of Sb ₂ O ₃ is preferably 0 to 1%, 0.01 to 0.5%, and particularly 0.05 to 0.4%. The content of SnO ₂ is preferably 0-1%, 0.01-0.5%, particularly 0.05-0.4%. The content of SnO ₂ +SO ₃ +Cl is preferably 0 to 1%, 0.001 to 1%, 0.01 to 0.5%, and particularly 0.01 to 0.3%. Here, "SnO ₂ + SO ₃ + Cl" refers to the total amount of SnO _2, SO ₃ and Cl.

Although PbO is a component which reduces high-temperature viscosity, it is preferable not to contain substantially from an environmental viewpoint.

Bi ₂ O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +Nb ₂ O ₅ +Ta ₂ O ₅ +WO ₃ is a component that increases the refractive index, but increases the collective cost. Therefore, the content of Bi ₂ O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +Nb ₂ O ₅ +Ta ₂ O ₅ +WO ₃ is preferably 9% or less, 6% or less, 3% or less, 2% or less, 1.5%, 1 % or less, less than 1%, particularly 0.5% or less, preferably substantially free. In addition, the content of Bi ₂ O ₃ , La ₂ O ₃ , Gd ₂ O ₃ , Nb ₂ O ₅ , Ta ₂ O ₅ , and WO ₃ is 9% or less, 6% or less, 3% or less, 2% or less, 1.5, respectively. %, 1% or less, less than 1%, especially 0.5% or less, preferably substantially free.

In addition to the above components, other components may be added. Its addition amount is preferably 10%, 5% or less, particularly 3% or less.

It is preferable that the high refractive index glass of this invention has the following characteristics.

The refractive index n _d is 1.51 or more, preferably 1.55 or more, 1.57 or more, 1.58 or more, 1.60 or more, 1.62 or more, and 1.63 or more. When the refractive index (n _d ) is less than 1.55, light cannot be efficiently extracted by reflection of the ITO-glass interface. On the other hand, when the refractive index n _d becomes high, the balance of a glass composition will be lost and devitrification resistance will fall easily. In addition, when the refractive index n _d becomes extremely high, the reflectance at the air-glass interface increases, and even if the glass surface is subjected to a roughening treatment, it becomes difficult to increase the light extraction efficiency. In addition, the introduction of heavy metal in the glass composition, but can increase the refractive index (n _d) After ensuring resistance to devitrification, ends up in this case the batch cost advance. Therefore, the refractive index n _d is 2.0 or less, preferably 1.70 or less, 1.68 or less, 1.67 or less, 1.66 or less, especially 1.65 or less.

The density is preferably 5.0 g/cm 3 or less, 4.8 g/cm 3 or less, 4.5 g/cm 3 or less, 4.3 g/cm 3 or less, 3.7 g/cm 3 or less, particularly 3.5 g/cm 3 or less. This makes the device lightweight. In addition, "density" can be measured by the well-known Archimedes method.

The coefficient of thermal expansion at 30 to 380°C is preferably 30×10 ^-7 /°C to 100×10 ^-7 /°C, 40×10 ^-7 /°C to 90×10 ^-7 /°C, 60×10 ^-7 /℃~85×10 ^-7 /℃, 65×10 ^-7 /℃~80×10 ^-7 /℃. In recent years, organic electroluminescent devices, such as organic electroluminescent lighting and an organic electroluminescent display, and a dye-sensitized solar cell WHEREIN: Flexibility may be calculated|required of a glass plate from a viewpoint of improving a design element. Although it is necessary to make the plate|board thickness of a glass plate small in order to improve a flexibility, when the thermal expansion coefficient of a transparent conductive film, such as a glass plate and ITO, FTO, becomes mismatched in this case, a glass plate will become easy to bend. Then, when the thermal expansion coefficient in 30-380 degreeC is made into the said range, it will become easy to prevent such a situation. In addition, "coefficient of thermal expansion in 30-380 degreeC" can be measured with a dilatometer etc.

The strain point is preferably 500°C or more, 540°C or more, 550°C or more, 580°C or more, 590°C or more, 600°C or more, 620°C or more, especially 640°C or more. In this way, a glass plate becomes difficult to heat-shrink by the high temperature heat processing in the manufacturing process of a device.

10 ^2.0 dPa · s at the temperature is preferably not less than 1000 ℃, more than 1100 ℃, more than 1130 ℃, more than 1200 ℃, more than 1220 ℃, more than 1240 ℃, more than 1250 ℃, in particular more than 1260 ℃. Since it becomes easy to raise the molding temperature in this way, it becomes easy to prevent devitrification at the time of shaping|molding.

The liquidus temperature is preferably 1200°C or less, 1150°C or less, 1130°C or less, 1100°C or less, 1050°C or less, 1030°C or less, especially 1000°C or less. Further, the liquid viscosity is preferably 10 ^3.0 dPa · s or more, 10 ^3.5 dPa · s or more, 10 ^4.0 dPa · s or more, 10 ^4.2 dPa · s or more, 10 ^4.5 dPa · s or more, 10 ^{4. 8} dPa · s or more, 10 ^{5. 0} dPa · s is at least, ^5. 10 ² dPa · s or more, particularly 10 ^5.3 dPa · s or more. In this way, glass becomes difficult to devitrify at the time of shaping|molding, and it becomes easy to shape|mold a glass plate by the float method and the overflow down-draw method.

The high refractive index glass of the present invention is preferably in the form of a flat plate, and the plate thickness is preferably 1.5 mm or less, 1.3 mm or less, 1.1 mm or less, 0.8 mm or less, 0.6 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 plate thickness, the higher the flexibility and it becomes easier to produce a lighting device excellent in design. However, when the plate thickness becomes extremely small, the glass is easily damaged. Therefore, the plate thickness is preferably 10 µm or more, particularly 30 µm or more.

In the case of the high refractive index glass of the present invention, it is preferable that at least one surface is unpolished in the case of a flat plate. Although the theoretical strength of glass is inherently very high, it often leads to fracture even with a stress much lower than the theoretical strength. This is because small defects called griffid flora on the surface occur in the process after molding, for example, in the polishing process. Therefore, since it will become difficult to impair the original mechanical strength of glass when the surface is made unpolished, a glass plate becomes difficult to break. Moreover, since a grinding|polishing process can be abbreviate|omitted when the surface is unpolished, the manufacturing cost of a glass plate can be reduced.

In the high refractive index glass of the present invention, the surface roughness (Ra) of at least one surface (provided that the effective surface) is preferably 10 angstroms or less, 5 angstroms or less, 3 angstroms or less, and particularly 2 angstroms or less. When the surface roughness (Ra) is greater than 10 Å, the quality of ITO formed on the surface is lowered, making it difficult to obtain uniform light emission.

The high refractive index glass of the present invention is preferably subjected to a roughening treatment on one surface by HF etching, sand blasting, or the like. The surface roughness Ra of the roughened surface is preferably 10 angstroms or more, 20 angstroms or more, 30 angstroms or more, and particularly 50 angstroms or more. When the roughened surface is placed on the side in contact with air such as organic EL lighting, the roughened surface has an anti-reflection structure, so that light generated from the organic light emitting layer is difficult to return into the organic light emitting layer, and as a result, light extraction efficiency can be increased. Moreover, you may provide an uneven|corrugated shape to one surface by heat processing, such as a press. This allows the formation of an accurate anti-reflective structure on one surface. What is necessary is just to adjust the space|interval and depth of an uneven|corrugated shape, taking the refractive index into consideration. Further, a resin film having an uneven shape (the surface roughness Ra is preferably 10 angstroms or more, 20 angstroms or more, 30 angstroms or more, particularly 50 angstroms or more) may be attached to one surface.

When a roughening process is carried out by an atmospheric pressure plasma process, while being able to form a uniform antireflection structure with respect to one surface, the surface state of the other surface can be maintained in a smooth state. It is also preferred to use a _{gas containing F (eg SF 6} , CF ₄ ) as the source of the atmospheric pressure plasma process. In this way, since the plasma containing the HF gas is generated, the efficiency of the roughening process is improved.

In addition, when forming an anti-reflection structure on the surface by a forming roll or the like during molding, the same effect can be obtained even without a roughening treatment. Moreover, you may stick the light-scattering film which has an uneven|corrugated shape on one surface.

It is preferable that the high refractive index glass of this invention has a light-scattering function by a powder phase. If it does in this way, even if it does not form a roughening process surface on one surface or affix a light-scattering film, it becomes easy to take out the light in a glass plate into the air. The timing to generate a powder phase in the manufacturing process of a glass plate may be any of the time of melting, shaping|molding, and slow cooling, and may generate a powder phase by heat-processing separately with respect to the glass in which a powder phase has not generate|occur|produced.

Next, the method of manufacturing the high refractive index glass of this invention is illustrated. First, a glass batch is produced by combining glass-making feedstock so that it may become a desired glass composition. Next, after melting and clarifying this glass batch, it shape|molds into a desired shape. After that, it is processed into a desired shape.

It is preferable that the high refractive index glass of this invention is shape|molded by the overflow down-draw method. In this way, a glass plate with good surface quality can be manufactured at low cost and in large quantities by unpolishing. Moreover, it becomes easy to aim at enlargement of a glass plate, and thickness reduction.

In addition to the overflow down-draw method, a float method, a slot down-draw method, a redraw method, a roll-out method, etc. can also be employ|adopted as a shaping|molding method of a glass plate, for example.

<Second invention>

The high refractive index glass according to the second invention contains SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ 30 to 80%, B ₂ O ₃ +ZnO 0.1 to 20%, TiO ₂ +ZrO ₂ 3 to 20% by mass% as a glass composition do. Although the reason for limiting the content range of each component as described above will be described below, detailed description will be omitted when it is common to the high refractive index glass according to the first invention. In addition, in the following description of the content range, % indication represents mass %, except for the case where there is special mention.

The content of _{SiO 2 + Al 2 O 3 +} B 2 O 3 is 30-80%, the preferred range of the content are the same as those of the first invention.

A preferable range of the content of each component of SiO _2, Al ₂ O ₃ and B ₂ O ₃ are the same as those of the first invention.

The weight ratio _{SiO 2 / (Al 2 O 3} + B 2 O 3) is preferably 2.5 ~ 4.6, 2.8 ~ 4.5 3 ~ 4.4, 3.2 ~ 4.3, 3.3 ~ 4.2 in order to achieve both the refractive index and devitrification, 3.4 ~ 4.1, Especially 3.5-4.

The content of B ₂ O ₃ +ZnO is 0.1 to 20% from the viewpoint of ensuring high liquidus viscosity, preferably 0.5 to 18%, 1 to 15%, 2 to 12%, 3 to 10%, 3.5 to 9%, Especially 4-8%.

The preferable range of content of ZnO is the same as that of 1st invention.

Mass ratio of ZnO / B ₂ O _3, preferably in order to achieve both the refractive index and devitrification is 0.1 to 1.2 0.2 to 1.2 0.3 to 1.1, 0.4 to 1, 0.4 to 0.9, especially 0.5 to 0.8.

A preferred range of the content of TiO ₂ + ZrO ₂ are the same as those of the first invention.

A preferable range of the content of each component of the TiO ₂ and ZrO ₂ are the same as those of the first invention.

Mass ratio of B ₂ O ₃ / TiO ₂ is preferably from 0.01 to 10, 0.1 to 5, 0.2 to 4, 0.3 to 3, 0.4 to 2, especially 0.5 to 1.5 in order to achieve both the refractive index and devitrification.

In addition to the above components, for example, the following components may be added.

As in the first invention, the content of MgO+CaO+SrO+BaO+ZnO may be 25 to 60%. The preferable content of MgO+CaO+SrO+BaO+ZnO is the same as that of 1st invention.

When mass ratio (MgO+CaO+SrO+BaO+ZnO)/CaO becomes small, a density and a thermal expansion coefficient will become high easily, and when the content becomes small, the balance of a glass composition will be lost and devitrification resistance will fall easily. Therefore, the mass ratio (MgO+CaO+SrO+BaO+ZnO)/CaO is preferably 2 or more, 3 or more, 4 or more, 5 or more, 6 or more, and particularly 7 or more. On the other hand, when mass ratio (MgO+CaO+SrO+BaO+ZnO)/CaO becomes large, refractive index, meltability, and Young's modulus will fall easily. Therefore, the mass ratio (MgO+CaO+SrO+BaO+ZnO)/CaO is preferably 10 or less, 9.5 or less, 9 or less, 8.5 or less, 8 or less, particularly 7.5 or less.

The preferable range of content of MgO+CaO is the same as that of 1st invention.

The preferable range of content of MgO is the same as that of 1st invention.

The content of CaO is preferably 12% or less, 10% or less, 8% or less, 6% or less, 4% or less, 3.5% or less, 3% or less, particularly 2.5% or less. In addition, the lower limit of content of CaO is the same as that of 1st invention.

The preferable range of content of SrO is the same as that of 1st invention.

The preferable range of content of BaO is the same as that of 1st invention.

A preferable range of the mass ratio of _{(SrO + BaO + TiO 2 +} ZrO 2) / (SiO 2 + Al 2 O 3 + B 2 O 3) is like the first invention.

Li ₂ O + Na ₂ O + K ₂ O is a component for lowering the viscosity of the glass, and although components for adjusting the coefficient of thermal expansion, the introduction of a large amount makes it difficult to ensure a high liquid viscosity be the viscosity of the glass is too lowered. In addition, it is therefore necessary to use a passivation film such as a SiO ₂ film formed on the surface of the glass. Accordingly, _{the content of Li 2} O+Na ₂ O+K ₂ O is preferably 15% or less, 10% or less, 5% or less, 2% or less, 1% or less, particularly 0.5% or less, and substantially not containing it. In addition, _{the content of Li 2} O, Na ₂ O, and K ₂ O is preferably 10% or less, 8% or less, 5% or less, 2% or less, 1% or less, particularly 0.5% or less, respectively, and substantially no it is preferable

As a clarifier, the thing similar to 1st invention can be added. In addition, content of a clarifier, etc. are the same as that of 1st invention.

It is preferable not to contain PbO substantially similarly to 1st invention.

_{Bi 2 O 3 + La 2 O} 3 + Gd 2 O 3 + Nb 2 O 5 + Ta 2 A preferable range of the content of O ₅ + WO ₃ is as with the first invention. Further, similarly to the first invention, a preferable range of the content of each component of _{Bi 2 O 3, La 2 O} 3, Gd 2 O 3, Nb 2 O 5, Ta 2 O 5, WO 3.

In addition to the above components, other components may be added. Its addition amount is preferably 10%, 5% or less, particularly 3% or less.

High refractive index glass is all the characteristics described in the first invention of the present invention [the refractive index (n _d), the density, the thermal expansion coefficient, strain point, 10 ^{2. 0} dPa · s temperature, liquid temperature, liquid viscosity, the shape of the, plate thickness and surface roughness]. In addition, the processing method etc. for providing the said various characteristics are carried out similarly to 1st invention.

As a manufacturing method of the high refractive index glass of this invention, the manufacturing method demonstrated by 1st invention is applicable similarly.

<Third invention>

The high refractive index glass according to the third invention is a containing 3 to 20% by weight of TiO ₂ + ZrO ₂ as a glass composition, and the weight ratio of (MgO + CaO + SrO + BaO + ZnO) / CaO is 2 to 10. Although the reason for limiting the content range of each component in this way is demonstrated below, when common with the high refractive index glass by 1st invention and 2nd invention, detailed description is abbreviate|omitted. In addition, in the description of the following content range, % indication represents mass %, except when there is a special mention.

The content of TiO ₂ + ZrO ₂ is 3 to 20%, the preferred range of the content are the same as those of the first invention.

A preferable range of the content of each component of the TiO ₂ and ZrO ₂ are the same as those of the first invention.

Mass ratio (MgO+CaO+SrO+BaO+ZnO)/CaO is 2-10, and the preferable range of the mass ratio is the same as that of 2nd invention.

The preferable range of content of MgO+CaO+SrO+BaO+ZnO is the same as that of 1st invention.

The preferable ranges of each component of MgO, SrO, BaO, and ZnO except CaO are the same as that of 1st invention.

When the content of CaO decreases, the refractive index, meltability, and Young's modulus tend to decrease. Therefore, the content of CaO is preferably more than 5%, not less than 6%, not less than 7%, in particular not less than 8%. On the other hand, when content of CaO increases, a density and a thermal expansion coefficient will become high easily, and when the content becomes excess, balance of a glass composition will be lost and devitrification resistance will fall easily. Accordingly, the content of CaO is preferably 15% or less, 13% or less, 12% or less, 11% or less, 10% or less, particularly 9% or less.

A preferred range of the content of SiO ₂ is, like the first invention.

A preferred range of the content of Al ₂ O ₃ is, like the first invention.

A preferred range of the content of B ₂ O ₃ are the same as those of the first invention.

Mass ratio of B ₂ A preferable range of the O ₃ / TiO ₂ are the same as those of the first invention.

The mass ratio (ZnO+B ₂ O ₃ )/TiO ₂ is preferably 0.7 to 10, more than 0.9 to 7, 1 to 5, 1.5 to 4.5, and particularly 1.8 to 3.5. In this way, devitrification resistance improves and it becomes easy to shape|mold a glass plate by the overflow down-draw method. Further, "ZnO + B ₂ O _3" is the total amount of ZnO and B ₂ O _3. "(ZnO + B ₂ O ₃₎ / TiO _2" indicates a value obtained by dividing the total amount of ZnO and B ₂ O ₃ in a content of TiO _2.

The preferable range of content of an alkali metal oxide is carried out similarly to 1st invention.

As a clarifier, the thing similar to 1st invention can be added. In addition, content of a clarifier, etc. are the same as that of 1st invention.

It is preferable not to contain PbO substantially similarly to 1st invention.

_{Bi 2 O 3 + La 2 O} 3 + Gd 2 O 3 + Nb 2 O 5 + Ta 2 A preferable range of the content of O ₅ + WO ₃ is as with the first invention. Further, similarly to the first invention, a preferable range of the content of each component of _{Bi 2 O 3, La 2 O} 3, Gd 2 O 3, Nb 2 O 5, Ta 2 O 5, WO 3.

TiO ₂ -(Bi ₂ O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +Nb ₂ O ₅ +Ta ₂ O ₅ +WO ₃ ) is preferably 0.1 or more, 0.5 or more, 1 or more, 1.5 or more, 2 to 8, 2.5 to 7 , especially 3 to 6. In this way, after reducing the batch cost, it becomes easy to raise refractive index. In addition, "TiO ₂ -(Bi ₂ O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +Nb ₂ O ₅ +Ta ₂ O ₅ +WO ₃ )" is _{Bi 2} O ₃ +La ₂ O ₃ +Gd ₂ O ₃ +Nb from the content _{of TiO 2 It} is the quantity obtained by subtracting the content of 2 O ₅ +Ta ₂ O ₅ +WO _{3 .}

In addition to the above components, other components may be added. Its addition amount is preferably 10%, 5% or less, particularly 3% or less.

High refractive index glass is all the characteristics described in the first invention of the present invention [the refractive index (n _d), the density, the thermal expansion coefficient, strain point, 10 ^{2. 0} dPa · s temperature, liquid temperature, liquid viscosity, the shape of the, plate thickness and surface roughness]. In addition, the processing method etc. for providing all the said characteristics are carried out similarly to 1st invention.

As a manufacturing method for the high refractive index glass of this invention, the manufacturing method demonstrated in 1st invention is applicable similarly.

<4th invention>

The high refractive index glass according to the fourth invention has a glass composition, in terms of mass%, of SiO ₂ 26-70%, B ₂ O ₃ 4.5-35%, MgO+CaO+SrO+BaO+ZnO 10-48%, BaO 10-31%, Li ₂ O+Na ₂ O+K ₂ O It contains 0-0.29%. Although the reason for limiting the content range of each component in this way is demonstrated below, when it is common with the high refractive index glass by 1st invention, 2nd invention, and 3rd invention, detailed description is abbreviate|omitted. In addition, in the description of the following content range, % indication represents mass %, except when there is a special mention.

The content of SiO ₂ is 26 to 70%. The content of SiO ₂ is preferably 26% or more, 30% or more, 32% or more, 34% or more, and particularly 36% or more. On the other hand, if the content of SiO ₂ be easily increases, the refractive index, melting properties, formability decreases. Therefore, _{the content of SiO 2} is preferably 70% or less, 65% or less, 60% or less, 55% or less, 53% or less, 51% or less, 48% or less, 45% or less, particularly 43% or less.

The content of B ₂ O ₃ is 4.5 to 35%. The upper limit of the content of B ₂ O ₃ is preferably 35%, 30%, 25%, 20%, 18%, particularly 16%. The lower limit of the content of B ₂ O ₃ is preferably 4.5%, 6%, 8%, 9%, particularly 10%.

The weight ratio SiO ₂ / B2O ₃ is 1.2 ~ 20 is preferable. The mass ratio of SiO ₂ / B ₂ O ₃ is small when the viscosity is reduced is apt to decrease viscosity of the liquid. Therefore, the lower limit of the mass ratio of SiO ₂ / B ₂ O ₃ is preferably 1.2, 1.4, 1.6, 1.8, 2.0, 2.2, 2.4, especially 2.5. On the other hand, the larger the mass ratio of SiO ₂ / B ₂ O _3, is reduced, substantial be easily covered with the liquid viscosity decreases. Therefore, the upper limit of the mass ratio of SiO ₂ / B ₂ O ₃ is preferably 20, 15, 10, 5, 4.0, 3.8, 3.6, 3.4, 3.2, and particularly 3.0.

The content of MgO+CaO+SrO+BaO+ZnO is preferably 10-48%, 20-47%, 25-46%, 30-45%, 32-42%, particularly 34-40%.

When the mass ratio (MgO+CaO+SrO+BaO+ZnO)/B ₂ O ₃ is regulated within a predetermined range, high refractive index, devitrification resistance, meltability, low density, and low coefficient of thermal expansion can be achieved simultaneously at high levels. Therefore, the lower limit of the mass ratio (MgO+CaO+SrO+BaO+ZnO)/B ₂ O ₃ is preferably 1, 1.5, 1.8, particularly 2, and the upper limit of the mass ratio (MgO+CaO+SrO+BaO+ZnO)/B ₂ O ₃ is preferably 6, 5, 4.5, particularly 4 is In addition, when the mass ratio (MgO+CaO+SrO+BaO+ZnO)/B ₂ O ₃ is too large, the density and the coefficient of thermal expansion may increase unreasonably, and when the content of the mass ratio (MgO+CaO+SrO+BaO+ZnO)/B ₂ O ₃ is too small, the refractive index, devitrification resistance, and meltability are too small. easy to degrade

The preferable range of content of MgO is the same as that of 1st invention.

The preferable range of content of CaO is the same as that of 2nd invention.

When regulating the mass ratio CaO / B ₂ O ₃ in a predetermined range is likely to increase resistance to devitrification. Therefore, the lower limit of the mass ratio CaO/B ₂ O ₃ is preferably 1, 2, 2.5, 3, particularly 3.5, and _{the upper limit of the mass ratio CaO/B 2} O ₃ is preferably 10, 8, 7, 6, particularly 5.5.

The preferable range of content of SrO is the same as that of 1st invention.

The upper limit of the content of BaO is preferably 31%, 28%, 26%, 24%, 22%, particularly 20%. The lower limit of the content of BaO is preferably 10%, 11%, 12%, 13%, 14%, 15%, particularly 16%.

When the mass ratio BaO/B ₂ O ₃ is regulated within a predetermined range, it is possible to achieve both high refractive index and solid-liquid viscosity at high levels. Therefore, the lower limit of the mass ratio BaO/B ₂ O ₃ is preferably 0.5, 0.6, 0.7, 0.8, 0.9, particularly 1, and _{the upper limit of the mass ratio BaO/B 2} O ₃ is preferably 5, 4.5, 4, 3.5. , 3, especially 2.5. Further, the mass ratio is a BaO / B ₂ O ₃ is too large it tends to be liquid viscosity is reduced, if the content is too small, the mass ratio of BaO / B ₂ O ₃ is apt to decrease the refractive index.

The upper limit of the content of ZnO is preferably 15%, 12%, 10%, 8%, 6%, particularly 4%. The preferable range of the lower limit of content of ZnO is the same as that of 1st invention.

The content of _{Li 2 O + Na 2 O +} K 2 O is preferably preferably 0.29% or less, 0.20% or less, or less than 0.10%, especially 0.05%, that is substantially free of. In addition, _{the content of Li 2} O, Na ₂ O, and K ₂ O is preferably 0.29% or less, 0.20% or less, 0.10% or less, particularly preferably 0.05% or less, and substantially not containing each component.

In addition to the above components, for example, the following components may be added.

As in the first invention, _{the content of Al 2} O ₃ may be 0 to 20%. The preferred content of Al ₂ O ₃ are the same as in the first invention.

The content of _{SiO 2 + Al 2 O 3 +} B 2 O 3 may be to 30.5 to 80%. The lower limit of the content of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ is preferably 30.5%, 35%, 40%, 42%, 46%, 50%, particularly 54%. The upper limit of the content of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ is preferably 80%, 75%, 70%, 65%, 62%, 61%, particularly 60%.

It is preferable not to contain PbO substantially similarly to 1st invention.

A preferred range of the content of Bi ₂ O _{3 + La 2 O 3 + Gd} 2 O 3 + Nb 2 O 5 + Ta 2 O 5 + WO shall, like the first invention. Further, similarly to the first invention, a preferable range of the content of each component of _{Bi 2 O 3, La 2 O} 3, Gd 2 O 3, Nb 2 O 5, Ta 2 O 5, WO 3.

A preferred range of the content of TiO ₂ are the same as those of the first invention.

A preferred range of the content of ZrO ₂ are the same as those of the first invention.

When the content of P ₂ O ₅ is reduced increases, covered with substantial loss of component balance of the glass composition. Accordingly, _{the content of P 2} O ₅ is preferably 15% or less, 10% or less, 6% or less, particularly 4% or less.

As a clarifier, the thing similar to 1st invention can be added. In addition, content of a clarifier, etc. are the same as that of 1st invention.

In addition to the above components, other components may be added. Its addition amount is preferably 10%, 5% or less, particularly 3% or less.

High refractive index glass is all the characteristics described in the first invention of the present invention [the refractive index (n _d), the density, the thermal expansion coefficient, strain point, 10 ^{2. 0} dPa · s temperature, liquid temperature, liquid viscosity, the shape of the, plate thickness and surface roughness]. In addition, the processing method etc. for providing all the said characteristics are carried out similarly to 1st invention.

Example 1

Hereinafter, an embodiment of the first invention will be described. In addition, the following examples are mere examples. The first invention is not at all limited to the following examples.

Table 1 and Table 2 have shown the Example (sample No. 1-21) of 1st invention.

First, after combining glass-making feedstock so that it might become the glass composition of Table 1 and Table 2, the obtained glass batch was supplied to a glass melting furnace, and it fuse|melted at 1400-1500 degreeC for 4 hours. Next, after pouring the obtained molten glass on a carbon plate and shape|molding it in flat plate shape, predetermined annealing treatment was performed. Various characteristics were evaluated about the finally obtained glass plate.

The density (rho) is a value measured by the well-known Archimedes method.

A thermal expansion coefficient (alpha) is the value which measured the average thermal expansion coefficient in 30-380 degreeC using the dilatometer. As a measurement sample, a cylindrical sample (the cross-section is R-processed) of (phi) 5 mm x 20 mm was used.

The strain point (Ps) is a value measured according to the method described in ASTM C336-71. Further, the higher the strain point Ps, the higher the heat resistance.

The slow cooling point (Ta) and the softening point (Ts) are values measured according to the method described in ASTM C338-93.

High-temperature viscosity of ^{10 4. 0 dPa · s, 10} 3. Temperature in ^{0 dPa · s, 10 2. 5} dPa · s and 10 ^{2. 0} dPa · s is measured with a platinum sphere pulling method. Moreover, it is excellent in a meltability and a moldability, so that these temperatures are low.

The liquidus temperature (TL) is a value obtained by measuring the temperature at which the glass powder remaining in the 50 mesh (300 μm) passed through the standard sieve 30 mesh (500 μm) was put in a platinum boat, maintained in a temperature gradient furnace for 24 hours, and crystals were precipitated. to be. In addition, liquidus viscosity (log?TL) points out the value which measured the viscosity of the glass in liquidus temperature by the platinum ball pulling-up method. Moreover, it is excellent in devitrification resistance and moldability, so that a liquidus viscosity is high and liquidus temperature is low.

The refractive index (n _d ) is a value measured using a refractive index meter KPR-2000 manufactured by Shimadzu Corporation, and is a value measured on the d line (wavelength 587.6 nm) of a hydrogen lamp. In addition, in the measurement, after producing a rectangular parallelepiped sample of 25 mm × 25 mm × about 3 mm, the temperature range from (Ta+30°C) to (Ps-50°C) is annealed at a cooling rate of 0.1°C/min, Subsequently, an immersion liquid having a matching refractive index was permeated between the glasses.

As apparent from Tables 1 and 2, sample No. 1-21 despite does not include the expensive heavy metal and a high refractive index (n _d), it was found to be satisfactory substantial covered.

In addition, sample No. After combining the glass raw material for each of the materials described in 1-21, the obtained glass batch was thrown into a continuous kiln, and it melted at the temperature of 1300-1500 degreeC. Then, with respect to the obtained molten glass, the glass plate of plate|board thickness 0.7mm was shape|molded by the overflow down-draw method. As a result of measuring the surface roughness (Ra) about the obtained glass plate, the value was all 2angstrom. In addition, surface roughness Ra is the value measured by the method based on JISB0601:2001.

Example 2

Hereinafter, an embodiment of the second invention will be described. In addition, the following examples are mere examples. The present invention is not limited in any way to the following examples.

Tables 3 to 13 show Examples (Sample Nos. 22 to 130) of the second invention.

First, after combining glass-making feedstock so that it might become the glass composition of Table 3 - Table 13, the obtained glass batch was supplied to a glass fusing furnace, and it fuse|melted at 1400-1500 degreeC for 4 hours. Next, after pouring the obtained molten glass on the carbon plate and shape|molding it in flat plate shape, predetermined annealing treatment was performed. Various characteristics were evaluated about the finally obtained glass plate.

In addition, density (ρ), coefficient of thermal expansion (α), strain point (Ps), slow cooling point (Ta), softening point (Ts), temperature in high temperature viscosity, liquidus temperature (TL), and refractive index (n _d ) The measurement method is the same as the method described in Example 1 according to the first invention.

As apparent from Tables 3 to 13, Sample No. 22-130 despite does not include the expensive heavy metal and a high refractive index (n _d), it was found to be satisfactory substantial covered.

In addition, sample No. 25, 28, 30, 31, 33, 35, 39~41, 44, 45, 47, 56, 57, 61, 63~65, 70, 71, 73, 78, 82~85, 87, 88, 91~ 94, 99, 102 to 106, 116, and 119, after combining a glass raw material for each of the materials, the obtained glass batch was thrown into a continuous kiln, and it melted at the temperature of 1300-1500 degreeC. Then, with respect to the obtained molten glass, the glass plate of plate|board thickness 0.7mm was shape|molded by the overflow down-draw method. As a result of measuring the surface roughness (Ra) about the obtained glass plate, the value was all 2angstrom. In addition, the measuring method of surface roughness Ra is carried out similarly to the method demonstrated in Example 1 by 1st invention.

Example 3

Hereinafter, an embodiment of the third invention will be described. In addition, the following examples are mere examples. The third invention is not at all limited to the following examples.

Table 14 has shown the Example (Sample No.131-141) of 3rd invention.

First, after combining glass raw materials so that it might become the glass composition of Table 14, the obtained glass batch was supplied to a glass fusing furnace, and it fuse|melted at 1400-1500 degreeC for 4 hours. Next, after pouring the obtained molten glass on a carbon plate and shape|molding in flat plate shape, predetermined annealing treatment was performed. Various characteristics were evaluated about the finally obtained glass plate.

In addition, density (ρ), coefficient of thermal expansion (α), strain point (Ps), slow cooling point (Ta), softening point (Ts), temperature in high temperature viscosity, liquidus temperature (TL), and refractive index (n _d ) The measurement method is the same as the method described in Example 1 according to the first invention.

As apparent from Table 14, sample No. 131-141 despite does not include the expensive heavy metal and a high refractive index (n _d), it was found to be satisfactory substantial covered.

In addition, sample No. After combining a glass raw material for each of the materials described in 131-138, 140, and 141, the obtained glass batch was put into a continuous kiln, and it melted at the temperature of 1300-1500 degreeC. Then, with respect to the obtained molten glass, the glass plate of plate|board thickness 0.7mm was shape|molded by the overflow down-draw method. As a result of measuring the surface roughness (Ra) about the obtained glass plate, the value was all 2angstrom. In addition, the surface roughness Ra is carried out similarly to the method demonstrated in Example 1 by 1st invention.

Example 4

Hereinafter, an embodiment of the fourth invention will be described. In addition, the following examples are mere examples. The fourth invention is not at all limited to the following examples.

Table 15 and Table 16 have shown the Example (Sample No. 142-166) of 4th invention.

First, after combining glass-making feedstock so that it might become the glass composition of Table 15, 16, the obtained glass batch was supplied to a glass melting furnace, and it fuse|melted at 1300-1400 degreeC for 7 hours. Then, after pouring the obtained molten glass on a carbon plate and shape|molding it in flat plate shape, the predetermined slow cooling process was performed. Various characteristics were evaluated about the finally obtained glass plate.

In addition, density (ρ), coefficient of thermal expansion (α), strain point (Ps), slow cooling point (Ta), softening point (Ts), temperature in high temperature viscosity, liquidus temperature (TL), and refractive index (n _d ) The measurement method is the same as the method described in Example 1 according to the first invention.

As apparent from Tables 15 and 16, Sample No. Although 142-166 did not contain an expensive heavy metal, the refractive index (n _d ) was high, and devitrification resistance was favorable.

Claims (17)

Glass composition in mass%, SiO ₂ 26-70%, MgO+CaO+SrO+BaO+ZnO 25-60%, MgO 0-10%, CaO 0-12%, SrO 0-20%, BaO 1-50%, ZnO 0-15%, TiO ₂ +ZrO ₂ 3 to 20%, TiO ₂ 0.01 to 15%, ZrO ₂ 0 to 10% is contained, and refractive index (n _d ) is 1.51 to 2.0, The high refractive index glass characterized by the above-mentioned. delete The method of claim 1,
High content of SiO ₂ +Al ₂ O ₃ +B ₂ O ₃ of 30 to 70 mass%, Al ₂ O ₃ content of 0-20 mass%, and B ₂ O ₃ content of 0-15 mass% refractive index glass. 4. The method of claim 3,
The high refractive index glass characterized by containing more than 5.0 mass % CaO. 4. The method of claim 1 or 3,
B ₂ O ₃ High refractive index glass comprising 0.1 to 15% by mass. delete 4. The method of claim 1 or 3,
ZrO ₂ High refractive index glass comprising 0.01 to 10% by mass. delete 4. The method of claim 1 or 3,
And the content of PbO is less than 0 ~ 0.5 mass%, and _{Bi 2 O 3 + La 2 O} 3 + Gd 2 O 3 + Nb 2 O 5 + Ta 2 O 5 + high-refractive index glass as is characterized in that not more than 9 mass%, the content of WO _3. 4. The method of claim 1 or 3,
0.1-15 mass % of ZnO is included, The high refractive index glass characterized by the above-mentioned. 4. The method of claim 1 or 3,
The content of alkali metal oxide is 0-0.5 mass %, The high refractive index glass characterized by the above-mentioned. 4. The method of claim 1 or 3,
A high refractive index glass having a liquidus viscosity of 10 ^{3.0 dPa·s or more.} 4. The method of claim 1 or 3,
A high refractive index glass having a flat plate shape and having a surface roughness (Ra) of at least one surface of 10 angstroms or less. 4. The method of claim 1 or 3,
A high-refractive-index glass formed by an overflow down-draw method. A lighting device comprising the high refractive index glass according to claim 1 or 3. Organic EL lighting comprising the high refractive index glass according to claim 1 or 3. An organic EL display comprising the high refractive index glass according to claim 1 or 3.