KR20130143639A - High-refractive-index glass - Google Patents

Abstract

The high-refractive-index glass of the present invention is characterized in that the glass composition contains 0 to 10% of B ₂ O ₃ , 0.001 to 35% of SrO, 0.001 to 30% of ZrO ₂ + TiO ₂ , La ₂ O ₃ + Nb ₂ O ₅ 0 to 10 %, A mass ratio BaO / SrO of 0 to 40, a mass ratio SiO ₂ / SrO of 0.1 to 40, and a refractive index nd of 1.55 to 2.3.

Description

High refractive index glass {HIGH-REFRACTIVE-INDEX GLASS}

The present invention relates to a high refractive index glass, for example, to an organic EL device, particularly a high refractive index glass suitable for organic EL illumination.

2. Description of the Related Art In recent years, display illumination using an organic EL light emitting element has attracted attention. These organic EL devices have a structure in which an organic light emitting element is sandwiched by a substrate (glass plate) on which a transparent conductive film such as ITO or FTO is formed (see, for example, Patent Document 1). In this structure, when a 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 the transparent conductive film and is emitted to the outside while repeating reflection in the glass plate.

Japanese Patent Application Laid-Open No. 2007-149460

The refractive index nd of the organic light emitting element is 1.8 to 1.9, and the refractive index nd of the transparent electrode film is 1.9 to 2.0. In contrast, the refractive index nd of the glass substrate is usually about 1.5. For this reason, the conventional organic EL device has a high reflectance due to the refractive index difference of the glass substrate-ITO interface, and there is a problem that light generated from the organic light emitting element can not be drawn efficiently.

When the high refractive index glass is used as the glass plate, the refractive index difference between the interface of the glass plate and the transparent electrode film can be reduced.

As optical glasses of high refractive index, optical glasses used for optical lenses and the like are known. BACKGROUND ART [0002] An optical glass in which a droplet glass molded into a spherical shape by a droplet forming method or the like is heat-treated again and press-molded into a predetermined shape is used for an optical lens or the like. Since this optical glass has a high refractive index nd but has a low liquid viscosity, the glass is dulled at the time of molding unless it is molded by a droplet forming method or the like which has a high cooling rate. Therefore, in order to solve the above problem, it is necessary to increase the resistance to high refractive index glass.

However, as the organic EL displays and the like are becoming thinner and larger, a plate thickness is small and a large-sized glass plate is required. In order to obtain such a glass plate, it is necessary to form it by a float method or a down-draw method (overflow down-draw method, slot down-draw method). However, since the conventional high refractive index glass has a low liquid viscosity, it can not be formed by the float method or the down-draw method, so that it is difficult to make it thin and large. In addition, there is a demand for thinning and enlargement in organic EL lighting.

On the other hand, when oxides, particularly LaO, Nb ₂ O ₅ and Gd ₂ O ₃ are added to the glass composition, the refractive index nd of the glass plate can be increased while suppressing the decrease of the liquid phase viscosity to some extent. However, such a rare metal oxide has a problem that the raw material cost is high. Further, when a rare metal oxide is added in a large amount in the glass composition, the resistance to devitrification is reduced, and it becomes difficult to form the glass plate. Further, when a rare metal oxide is added in a large amount, the oxidation resistance is lowered.

Thus, the present invention despite the low content of rare metal oxides (in particular _{La 2 O 3, Nb 2 O} 5, Gd 2 O 3) and matched to the organic light emitting element and the transparent electrode film, the refractive index nd, and also substantial full of good and And a refractive index glass.

<First Invention>

As a result of intensive studies, the inventors of the present invention have found that the above technical problem can be solved by regulating the content range of each component and the refractive index in a predetermined range, and as a first invention. That is, the high-refractive-index glass according to the first aspect of the present invention has a glass composition containing 0 to 10% of B ₂ O ₃ , 0.001 to 35% of SrO, 0.001 to 30% of ZrO ₂ + TiO ₂ , La ₂ O ₃ + Nb ₂ O ₅ 0 to 10%, a mass ratio BaO / SrO of 0 to 40, a mass ratio SiO ₂ / SrO of 0.1 to 40, and a refractive index nd of 1.55 to 2.3. Here, "ZrO ₂ + TiO ₂ " refers to the sum of ZrO ₂ and TiO ₂ . &Quot; La ₂ O ₃ + Nb ₂ O ₅ &quot; refers to the sum of La ₂ O ₃ and Nb ₂ O ₅ . (Refractive index nd) can be measured with a commercially available refractive index measuring instrument. For example, a rectangular parallelepiped sample having a size of 25 mm x 25 mm x approximately 3 mm is prepared (standing point Ta + 30 deg. C) Can be measured by using a refractive index measuring instrument KPR-2000 manufactured by Shimadzu Seisakusho Co., Ltd. under the condition that the temperature region of the glass substrate is annealed at a cooling rate of 0.1 deg. "Standing point Ta" refers to a value measured by the method described in ASTM C338-93. &Quot; Ps Ps Ps &quot; refers to the value measured by the method described in ASTM C336-71.

Secondly, it is preferable that the high-refractive-index glass of the first invention has a liquid-phase viscosity of 10 ^3.0 dPa · s or more. Here, the &quot; liquid-phase viscosity &quot; refers to a value obtained by measuring the viscosity of the glass at the liquidus temperature by the platinum rolling method. The "liquid phase temperature" is a value obtained by passing the glass powder passing through a standard 30 mesh (500 μm) and remaining in 50 mesh (300 μm) into a platinum boat and holding it in a temperature gradient for 24 hours, Lt; / RTI &gt;

Thirdly, it is preferable that the high-refractive-index glass of the first invention is in the form of a plate. Here, the &quot; plate shape &quot; is not limitedly interpreted, and includes a film shape having a small plate thickness, for example, a film shape glass provided along a column, and also includes a concavo-convex shape formed on one side.

Fourth, the high-refractive-index glass of the first invention is preferably formed by a float method.

Fifthly, it is preferable that the temperature of the high refractive index glass of the first aspect of the present invention at 10 ⁴ dPa 가 is 1250 캜 or lower. Here, "the temperature in 10 ^4.0 dPa * s" points out the value measured by the platinum ball pulling-up method.

Sixth, it is preferable that the high refractive index glass of the first invention has a melting point of 650 ° C or higher.

Seventh, the high refractive index glass of the first invention is preferably used in an illumination device.

Eighth, it is preferable that the high refractive index glass of the first invention is used in organic EL illumination.

Ninthly, it is preferable that the high refractive index glass of the first invention is used in an organic EL display.

The high refractive index glass of the first aspect of the present invention is characterized in that the glass composition contains 0 to 8% of B ₂ O ₃ , 0.001 to 35% of SrO, 0 to 12% of ZnO, 0.001 to 30% of ZrO ₂ + TiO ₂ , La ₂ O ₃ + Nb ₂ O ₅ 0 to 5%, Li ₂ O + Na ₂ O + K ₂ O 0 to 10%, a mass ratio of BaO / SrO of 0 to 20, a mass ratio of SiO ₂ / SrO of 0.1 to 20 , A mass ratio (MgO + CaO) / SrO of 0 to 20, a refractive index nd of 1.58 or more, a liquid viscosity of 10 ^3.5 dPa s or more and a point of 670 캜 or more. Here, &quot; Li ₂ O + Na ₂ O + K ₂ O &quot; refers to the sum of Li ₂ O, Na ₂ O, and K ₂ O. &Quot; MgO + CaO &quot; refers to the sum of MgO and CaO.

In the eleventh aspect, the high refractive index glass according to the first aspect of the present invention comprises 10 to 50% of SiO ₂ , 0 to 8% of B ₂ O _3, 0 to 10% of CaO, 0.001 to 35% of SrO, , 0 to 4% of ZnO, 0.001 to 30% of ZrO ₂ + TiO ₂ , 0 to ₅ % of La ₂ O ₃ + Nb ₂ O _{5 and} 0 to ₂ % of Li ₂ O + Na ₂ O + K ₂ O , mass ratio of BaO / SrO is 0 to 20, the weight ratio SiO ₂ / SrO is 1 to 15, the mass ratio (CaO + MgO) / and SrO is 0 to 20, the refractive index nd more than 1.6, the liquid viscosity of 10 ^4.0 dPa · s or more, And the point is at least 670 ° C.

Claim 12, the first 1 SiO ₂ 0.1~60% glass sheet for lighting device of the invention is a glass composition in terms of percent by _{mass, B 2 O 3 0~10%,} SrO 0.001~35%, BaO 0~40%, ZrO 2 + 0.001 to 30% of TiO ₂ , 0 to 10% of La ₂ O ₃ + Nb ₂ O ₅ , and a refractive index nd of 1.55 to 2.3.

Claim 13 as, SiO ₂ 0.1~60% organic EL lighting glass plate is, in weight percent as the glass composition of the first aspect of the _{invention, B 2 O 3 0~10%,} SrO 0.001~35%, BaO 0~40%, ZrO 2 + 0.001 to 30% of TiO ₂ , 0 to 10% of La ₂ O ₃ + Nb ₂ O ₅ , and a refractive index nd of 1.55 to 2.3.

14 to, SiO ₂ 0.1~60% glass plate for an organic EL display, in mass% as the glass composition of the first aspect of the _{invention, B 2 O 3 0~10%,} SrO 0.001~35%, BaO 0~40%, ZrO 2 + TiO ₂ 0.001 to 30%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 10%, and a refractive index nd of 1.55 to 2.3.

In the fifteenth aspect, the high-refractive-index glass according to the first aspect of the present invention has a composition of 35 to 60% SiO ₂ , 0 to 1.5% of Li ₂ O + Na ₂ O + K ₂ O, 0.1 to 35% of SrO, 35 to 35%, TiO ₂ 0.001 to 25%, La ₂ O ₃ + Nb ₂ O ₅ + 0 to 9% Gd ₂ O ₃ , and a refractive index nd of 1.55 to 2.3. Here, "La ₂ O ₃ + Nb ₂ O ₅ + Gd ₂ O ₃ " refers to the sum of La ₂ O ₃ , Nb ₂ O ₅ , and Gd ₂ O ₃ .

Claim 16, the high refractive index glass is SiO ₂ 35~60% in mass% as the glass composition of the first aspect of the invention, Li ₂ O + Na ₂ O + K ₂ O 0~1.5%, 0.1~20% SrO, BaO 17~ 35 to 35%, TiO ₂ 0.01 to 20%, La ₂ O ₃ + Nb ₂ O ₅ + 0 to 9% Gd ₂ O ₃ , and a refractive index nd of 1.55 to 2.3.

In the seventeenth aspect, it is preferable that the content of B ₂ O ₃ is 0 to 3 mass% in the high refractive index glass of the first invention.

In the eighteenth aspect, it is preferable that the content of MgO in the high refractive index glass of the first invention is 0 to 3 mass%.

In the 19th aspect, the high refractive index glass of the first aspect of the present invention preferably further contains 1 to 20% by mass of ZrO ₂ + TiO ₂ .

In the twentieth aspect, it is preferable that the high-refractive-index glass of the first invention is formed by a down-draw method. Here, the &quot; down-draw method &quot; includes an overflow down-draw method, a slot-down-draw method, and a read-low method.

<Second invention>

As a result of intensive studies, the inventors of the present invention discovered that the above technical problem can be solved by regulating the glass composition range to a predetermined range, and propose the second invention. That is, the high-refractive-index glass of the second aspect of the invention has 30 to 60% of SiO ₂ , 0 to 15% of B ₂ O _3, 0 to 15% of Al ₂ O _3, 0 to 10% of Li ₂ O, ₂ O 0-10%, K ₂ O 0-10%, MgO + CaO + SrO + BaO + 20-60% ZnO, 0.0001-20% TiO _2, 0-20% ZrO ₂ , La ₂ O ₃ + Nb ₂ O ₅ 0 to 10%, and a refractive index nd of 1.55 to 2.3. Here, "MgO + CaO + SrO + BaO + ZnO" refers to the sum of MgO, CaO, SrO, BaO, and ZnO. &Quot; La ₂ O ₃ + Nb ₂ O ₅ &quot; refers to the sum of La ₂ O ₃ and Nb ₂ O ₅ . "Refractive index nd" can be measured with a refractive index measuring device. For example, a rectangular parallelepiped sample having a size of 25 mm × 25 mm × 3 mm is prepared, and then a temperature of (Ta Lang + 30 ° C.) Can be measured by annealing the region at a cooling rate of 0.1 占 폚 / min, and then using a refractive index measuring apparatus KPR-200 of Carnoy, while penetrating the submerged solution with the refractive index nd into the glass. "Standing point Ta" refers to a value measured by the method described in ASTM C338-93. &Quot; Ps Ps Ps &quot; refers to the value measured by the method described in ASTM C336-71.

High refractive index glass of the second aspect of the invention is a _{SiO 2 30~60%, B 2 O} 3 0~15%, Al 2 O 3 0~15%, MgO + CaO + SrO + BaO + ZnO 20~60%, TiO 2 0.0001 To 20%, and ZrO ₂ 0 to 20%. By doing so, it is possible to increase the refractive index nd and increase the resistance to devitrification.

The high-refractive-index glass of the second invention contains 0 to 10% of La ₂ O ₃ + Nb ₂ O ₅ . By doing so, it is possible to reduce the cost of the raw material and increase the resistance and acid resistance.

The high-refractive-index glass of the second invention contains 0 to 10% of Li ₂ O, 0 to 10% of Na ₂ O and 0 to 10% of K ₂ O. By doing so, the acid resistance is improved and the glass becomes less cloudy by the elution of the alkali component in the etching process by the acid. Further, the acid etching process is included in the production process of the organic EL display or the like, and if the acid resistance of the glass plate is low, the glass plate is eroded in this etching process and opacified. When the glass plate is opaque, the transmittance of the glass plate is lowered, making it difficult to make the display high-definition.

The high-refractive-index glass of the second invention has a refractive index nd of 1.55 to 2.3. This makes it easy to match the refractive index nd of the organic light emitting element or the transparent conductive film, and can efficiently draw light generated from the organic light emitting element to the outside.

Second, the high-refractive-index glass of the second aspect of the present invention contains 35 to 60% of SiO ₂ , 0 to 15% of B ₂ O _3, 0 to 15% of Al ₂ O _3, 0 to 10% of Li ₂ O, _{, Na 2 O 0~10%, K} 2 O 0~10%, 20~60% MgO + CaO + SrO + BaO + ZnO, TiO 2 0.0001~20%, ZrO 2 0.0001~20%, La 2 O 3 + Nb ₂ O ₅ 0 to 10%, and a refractive index nd of 1.55 to 2.3.

Third, the high-refractive-index glass according to the second aspect of the present invention contains 35 to 60% of SiO ₂ , 0 to 15% of B ₂ O _3, 0 to 15% of Al ₂ O _3, 0 to 1% of Li ₂ O, 0 to 1% of Na ₂ O, 0 to 1% of K ₂ O, 0 to 1% of Li ₂ O + Na ₂ O + K ₂ O, 20 to 50% of MgO + CaO + SrO + BaO + ZnO, , 0.0001 to 20% of TiO _2, 0.0001 to 20% of ZrO ₂ , 0 to 10% of La ₂ O ₃ + Nb ₂ O ₅ , and a refractive index nd of 1.55 to 2.3. Here, &quot; Li ₂ O + Na ₂ O + K ₂ O &quot; refers to the sum of Li ₂ O, Na ₂ O, and K ₂ O.

Fourth, the high-refractive-index glass of the second invention preferably contains 1% by mass or more of B ₂ O ₃ .

Fifthly, the high refractive index glass of the second invention preferably contains MgO in an amount of 1% by mass or more.

Sixth, the high-refractive-index glass of the second invention is preferably plate-like. This makes it easy to apply to substrates of various devices such as organic EL displays, organic EL lights, and organic thin film solar cells. Here, the &quot; plate shape &quot; is not limitedly interpreted and includes film-shaped glass such as a film having a small plate thickness, for example, provided along a column, and includes a concavo-convex shape formed on one side.

Seventh, it is preferable that the high refractive index glass of the second invention has a liquid viscosity of 10 ^3.0 dPa · s or more. There is a problem that the current density at the time of current application changes due to the minute difference in the surface smoothness of the glass plate, and the unevenness of the illuminance is caused. Further, if the glass surface is polished to increase the surface smoothness of the glass plate, there arises a problem that the processing cost is increased. Therefore, when the liquidus viscosity is in the above-mentioned range, it is easy to form a glass plate by an overflow down-draw method or the like, and as a result, it becomes easy to produce a glass plate having a good surface smoothness. Here, the &quot; liquid-phase viscosity &quot; refers to a value obtained by measuring the viscosity of the glass at the liquidus temperature by the platinum rolling method. The &quot; liquid temperature &quot; is a value obtained by passing the glass powder passing through a standard 30 mesh (500 mu m) and remaining in 50 mesh (300 mu m) into a platinum boat and holding it in a temperature gradient for 24 hours, Point. The &quot; overflow down-draw method &quot; is a method in which the molten glass is flooded from both sides of the heat-resistant trough-like structure, and the molten glass overflowing is formed by downward drawing while the molten glass is merged at the lower end of the trough-like structure.

Eighth, it is preferable that the high-refractive-index glass of the second invention is formed by a float method or a down-draw method. Here, the &quot; down-draw method &quot; includes an overflow down-draw method, a slot-down draw method, and the like.

It is preferable that the high-refractive-index glass of the second invention has a surface which is not polished at least on one side, and the surface roughness Ra of the surface is 10 angstrom or less. Here, &quot; surface roughness Ra &quot; refers to a value measured by a method in accordance with JIS B0601: 2001.

(Effects of the Invention)

According to the first invention and the second invention, the refractive index nd of the organic light emitting element or the transparent electrode film is adjusted while the content of the rare metal oxide (particularly, La ₂ O ₃ , Nb ₂ O ₅ , and Gd ₂ O ₃ ) It is possible to provide a high refractive index glass that is resistant to devitrification.

&Lt; First Embodiment >

No. (hereinafter referred to as first embodiment), the embodiment of the first invention has a high refractive index glass as the glass composition, in weight percent B ₂ O ₃ 0~10% by, 0.001~35% SrO, ZrO ₂ + TiO ₂ 0.001~ It is _{30%, La 2 O 3 +} Nb 2 O 5 0~10% and containing, by mass ratio BaO / SrO is 0 to 40, the weight ratio SiO ₂ / SrO is 0.1 to 40 a. The reasons for limiting the content range of each component as described above will be explained below. In the following description of the content range, "%" represents% by mass unless otherwise specified.

The content of B ₂ O ₃ is 0 - 10% is preferred. When the content of B ₂ O ₃ is increased, the refractive index nd or the Young's modulus tends to be lowered. Therefore, the upper limit of the preferable range of B ₂ O ₃ is 8% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, particularly 1% or less.

The content of SrO is preferably 0.001 to 35%. SrO is a component having a high effect of increasing the refractive index nd while suppressing the relatively low saturation of the alkaline earth metal oxide. However, if the content of SrO is increased, the refractive index nd, the density, the thermal expansion coefficient become high, the component balance of the glass composition becomes poor, and the resistance to devitrification tends to decrease. Therefore, the upper limit of the preferable range of SrO is 30% or less, 25% or less, 20% or less, 15% or less, 12% or less, 10% or less, particularly 8% or less. The preferable lower limit of the SrO content is at least 0.01%, at least 0.1%, at least 1%, at least 2%, at least 3%, at least 3.5%, especially at least 4%.

The content of TiO ₂ + ZrO ₂ is preferably 0.001 to 30%. If the content of TiO ₂ + ZrO ₂ is increased, the resistance to devitrification tends to be lowered, or the density and thermal expansion coefficient may be excessively high. On the other hand, when the content of TiO ₂ + ZrO ₂ is decreased, the refractive index nd is likely to decrease. Therefore, the upper limit of the preferable range of TiO ₂ + ZrO ₂ is 25% or less, 20% or less, 18% or less, 15% or less, 14% or less, particularly 13% or less. The lower limit of the range of TiO ₂ + ZrO ₂ is at least 0.01%, at least 0.5%, at least 1%, at least 3%, at least 5%, at least 6%, especially at least 7%.

The content of TiO ₂ is preferably 0 to 30%. TiO ₂ is a component that increases the refractive index nd. However, when the content of TiO ₂ is increased, the density and the coefficient of thermal expansion become too high, resistance to devitrification tends to decrease, and the transmittance tends to decrease. Therefore, the upper limit of the preferable range of TiO ₂ is 25% or less, 15% or less, 12% or less, particularly 8% or less. The lower limit of the TiO ₂ is preferably 0.001% or more, 0.01% or more, 0.5% or more, 1% or more, and particularly 3% or more.

The content of ZrO ₂ is preferably 0 to 30%. ZrO ₂ improves the refractive index nd and has a high effect of increasing the viscosity near the liquid phase temperature. However, when the content of ZrO ₂ is large, the density becomes too high, and the resistance to devitrification tends to decrease. Therefore, the preferred upper limit of the range of ZrO ₂ is 15% or less, 10% or less, 7% or less, particularly 6% or less. The lower limit of the range of ZrO ₂ is preferably 0.001% or more, 0.01% or more, 0.5% or more, 1% or more, 2% or more, especially 3% or more.

The content of La ₂ O ₃ + Nb ₂ O ₅ is preferably 0 to 10%. If the content of La ₂ O ₃ + Nb ₂ O ₅ is increased, the refractive index nd tends to be higher. However, if the content of La ₂ O ₃ + Nb ₂ O ₅ is more than 10%, the balance of the glass composition may be lacking and the resistance to devitrification may decrease. There is concern that this may arise. Particularly, inexpensive glass is required in applications such as lighting, so that an increase in raw material costs is not preferable. Therefore, the lower limit of the range of La ₂ O ₃ + Nb ₂ O ₅ is preferably 9% or less, 8% or less, 5% or less, 3% or less, 2% or less, 1% or less, 0.5% or less,

La ₂ O ₃ is a component that increases the refractive index nd. If the content of La ₂ O ₃ is increased, the resistance to devitrification tends to be lowered, and the density and thermal expansion coefficient may be excessively high. Therefore, the content of La ₂ O ₃ is preferably 10% or less, 9% or less, 8% or less, 5% or less, 2% 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 nd. If the content of Nb ₂ O ₅ is increased, the resistance to devitrification tends to be lowered, and the density and the thermal expansion coefficient may become excessively high. Therefore, the content of Nb ₂ O ₅ is preferably 10% or less, 9% or less, 8% or less, 5% or less, 2% or less, 1% or less, 0.5% or less, particularly 0.1% or less.

The mass ratio (La ₂ O ₃ + Nb ₂ O ₅ ) / (ZrO ₂ + TiO ₂ ) is preferably 0 to 30. The mass ratio _{(La 2 O 3 + Nb 2} O 5) / (ZrO 2 + TiO 2) is higher while suppressing the deterioration of resistance to devitrification, but makes it possible to increase the refractive index nd, this value is too large, the component balance of the glass composition lacks And the cost of raw materials becomes excessively high. Therefore, the preferable upper limit of the mass ratio (La ₂ O ₃ + Nb ₂ O ₅ ) / (ZrO ₂ + TiO ₂ ) is 20 or less, 10 or less, 5 or less, 2 or less, 1 or less,

The mass ratio BaO / SrO is 0 to 40. If the mass ratio of BaO / SrO is too large, the resistance to devitrification may decrease or the density and thermal expansion coefficient may become excessively high. On the other hand, if the mass ratio BaO / SrO is too small, the refractive index nd may be lowered, or the component balance of the glass composition may be lacking, thereby reducing the resistance to devitrification. Therefore, the upper limit of the preferable range of the mass ratio of BaO / SrO is 30 or less, 20 or less, 10 or less, 8 or less, particularly 5 or less. The preferred lower limit of the mass ratio of BaO / SrO is 0.1 or more, 0.5 or more, 1 or more, 2.5 or more, and especially 3 or more.

BaO is a component of the alkaline earth metal oxide which increases the refractive index nd without extremely lowering the viscosity of the glass. The content of BaO is preferably 0 to 40%. As the content of BaO increases, the refractive index nd, density, and thermal expansion coefficient tend to increase. However, when the content of BaO exceeds 40%, the component balance of the glass composition is lost, and resistance to devitrification tends to decrease. Therefore, the upper limit of the preferable range of BaO is preferably 35% or less, 32% or less, 30% or less, 29.5% or less, 29% or less, particularly 28% or less. However, if the content of BaO is decreased, it becomes difficult to obtain a desired refractive index nd, and it becomes difficult to secure a high liquid viscosity. Therefore, the lower limit of the preferable range of BaO is preferably 0.5% or more, 1% or more, 2% or more, 5% or more, 10% or more, 15% or more, 17% or more, 20% or more, 23% or more, Do.

The mass ratio SiO ₂ / SrO is 0.1 to 40. If the mass ratio SiO ₂ / SrO is excessively large, the refractive index nd tends to decrease. On the other hand, if the mass ratio SiO ₂ / SrO is too small, the resistance to devitrification tends to be lowered, or the density and the thermal expansion coefficient may become excessively high. Accordingly, the upper limit of the preferable range of the mass ratio SiO ₂ / SrO is 30 or less, 20 or less, 15 or less, 10 or less, 9 or less, and particularly 8 or less. The lower limit of the mass ratio SiO ₂ / SrO is preferably 0.5 or more, 1 or more, 2 or more, 2.5 or more, especially 3 or more.

The content of SiO ₂ is a 0.1~60% is preferred. When the content of SiO ₂ is increased, the meltability and moldability are likely to be lowered, and the refractive index nd is likely to be lowered. Therefore, the content of SiO ₂ is preferably 55% or less, 53% or less, 52% or less, 50% or less, 49% or less, 48% or less, particularly 45% or less. On the other hand, if the content of SiO ₂ is decreased, it is difficult to form a glass network structure, and vitrification becomes difficult. Further, the viscosity of the glass is excessively lowered, making it difficult to secure a high liquid-phase viscosity. Therefore, the content of SiO ₂ is preferably 3% or more, 5% or more, 10% or more, 15% or more, 20% or more, 25% or more, 30% or more, 35% or more and more preferably 40% or more.

The content of Al ₂ O ₃ is 0 - 20% is preferred. When the content of Al ₂ O ₃ is increased, the crystal is liable to precipitate on the glass, so that the liquid phase viscosity tends to be lowered, and the refractive index nd is likely to be lowered. Therefore, the preferable upper limit range of Al ₂ O ₃ is 15% or less, 10% or less, 8% or less, particularly 6% or less. In addition, when the content of Al ₂ O ₃ is decreased, the balance of the components of the glass composition is lacking, and on the contrary, the glass is liable to fail. Therefore, the lower limit of the preferable range of Al ₂ O ₃ is 0.1% or more, 0.5% or more, 1% or more, particularly 3% or more.

The content of MgO is preferably 0 to 10%. MgO is a component that increases the refractive index nd, Young's modulus, and the point of weakening, and also lowers the high temperature viscosity. However, when a large amount of MgO is added, the liquid phase temperature rises and the resistance to devitrification may decrease or the density and thermal expansion coefficient may become excessively high. Therefore, the upper limit of the preferable range of MgO is 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 preferably 0 to 10%. If the content of CaO is increased, the density and the thermal expansion coefficient are liable to be increased. If the content of CaO is too large, the component balance of the glass composition is lost and resistance to devitrification tends to decrease. Therefore, the upper limit of the range of CaO is preferably not more than 9%, particularly not more than 8.5%. Further, when the content of CaO is decreased, the meltability is lowered, the Young's modulus is lowered, and the refractive index nd is likely to be lowered. Therefore, the lower limit of the range of CaO is preferably 0.5% or more, 1% or more, 2% or more, 3% or more, particularly 4% or more.

The mass ratio (MgO + CaO) / SrO is preferably 0 to 20. When the mass ratio (MgO + CaO) / SrO is increased, it is possible to lower the glass density or lower the high-temperature viscosity while maintaining a high refractive index nd, but the liquidus temperature tends to be high and it is difficult to maintain a high liquidus viscosity. Therefore, a preferable upper limit range of the mass ratio (MgO + CaO) / SrO is 10 or less, 8 or less, 5 or less, 3 or less, 2 or less,

The content of ZnO is preferably 0 to 12%. If the content of ZnO is increased, the density and the thermal expansion coefficient become excessively high, the component balance of the glass composition is lost, and the resistance to devitrification tends to deteriorate, and the high-temperature viscosity tends to be too low. Therefore, a preferable upper limit range of ZnO is 8% or less, 4% or less, 2% or less, 1% or less, 0.5% or less, 0.1% or less, particularly 0.01% or less.

The content of La ₂ O ₃ + Nb ₂ O ₅ + Gd ₂ O ₃ is preferably 0 to 10%. When the content of La ₂ O ₃ + Nb ₂ O ₅ + Gd ₂ O ₃ is large, the refractive index nd tends to be high. However, if the content of the La ₂ O ₃ + Nb ₂ O ₅ + Gd ₂ O ₃ exceeds 10%, the component balance of the glass composition becomes poor, So that the manufacturing cost of the glass may increase. Particularly, inexpensive glass is required in applications such as lighting, so that an increase in raw material costs is not preferable. Therefore, the lower limit range of La ₂ O ₃ + Nb ₂ O ₅ + Gd ₂ O ₃ is preferably 9% or less, 8% or less, 5% or less, 3% or less, 2% or less, 1% or less, 0.1% or less.

The content of Gd ₂ O ₃ is preferably 0 to 10%. Gd ₂ O ₃ is a component for increasing the refractive index. However, if the content of Gd ₂ O ₃ is increased, the density or the thermal expansion coefficient becomes excessively high, the component balance of the glass composition is lacked and the resistance to devitrification lowers, It becomes difficult to secure the viscosity. Therefore, the upper limit of the preferable range of Gd ₂ O ₃ is 8% or less, 4% or less, 2% or less, 1% or less, 0.5% or less, 0.1% or less, particularly 0.01% or less.

The content of Li ₂ O + Na ₂ O + K ₂ O is preferably 0 to 15%. Li ₂ O + Na ₂ O + K ₂ O is a component that lowers the viscosity of the glass and is also a component that adjusts the thermal expansion coefficient. However, when a large amount of Li ₂ O + Na ₂ O + K ₂ O is added, It is excessively deteriorated and it becomes difficult to secure a high liquid-phase viscosity. Therefore, the upper limit of the preferable range of Li ₂ O + Na ₂ O + K ₂ O is 10% or less, 5% or less, 2% or less, 1.5% or less, 1% or less, 0.5% or less, particularly 0.1% or less.

As the clarifying agent, 0 to 3% of one or more selected from the group consisting of As ₂ O ₃ , Sb ₂ O ₃ , CeO ₂ , SnO ₂ , F, Cl and SO ₃ may be added. However, As ₂ O ₃ , Sb ₂ O ₃ , and F, especially As ₂ O ₃ and Sb ₂ O _3, are preferably avoided from the environmental viewpoint, and their content is preferably less than 0.1% . Considering the above points, SnO ₂ , SO ₃ , and Cl are preferable as the fining agent. In particular, the content of SnO ₂ is preferably 0 to 1%, 0.01 to 0.5%, particularly 0.05 to 0.4%. The content of SnO ₂ + SO ₃ + Cl is preferably 0 to 1%, 0.001 to 1%, 0.01 to 0.5%, particularly preferably 0.01 to 0.3%. Here, &quot; SnO ₂ + SO ₃ + Cl &quot; refers to the sum of SnO ₂ , SO ₃ , and Cl.

PbO is a component that lowers the high-temperature viscosity, but it is preferable to minimize its use from the viewpoint of environment, and its content is preferably 0.5% or less, more preferably 1000 ppm (mass) or less.

Bi ₂ O ₃ is a component that lowers the high-temperature viscosity, but from the environmental point of view, its use is preferably avoided to the utmost, and its content is preferably 0.5% or less, more preferably 1000 ppm (mass) or less.

It is naturally possible to construct a preferable glass composition range by combining the preferable ranges of the respective components. Among them, particularly preferable glass composition ranges from the viewpoints of refractive index nd, resistance to devitrification, production cost and the like are as follows.

(1) SiO ₂ 20~50% in mass% as a glass _{composition, B 2 O 3 0~8%,} CaO 0~10%, SrO 0.01~35%, BaO 0~30%, ZnO 0~4%, ZrO ₂ + TiO ₂ 0.001 to 20%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 3%, Li ₂ O + Na ₂ O + K ₂ O 0 to 1%, and a mass ratio BaO / SrO of 0 to 20 , A mass ratio SiO ₂ / SrO of 1 to 15, and a mass ratio (MgO + CaO) / SrO of 0 to 10.

₍₂₎ SiO 2 35~50% in mass% as a glass _{composition, B 2 O 3 0~5%,} CaO 0~9%, SrO 1~35%, BaO 0~29%, ZnO 0~3%, ZrO ₂ + TiO ₂ 1 to 15%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 0.1%, Li ₂ O + Na ₂ O + K ₂ O 0 to 0.1%, and a mass ratio BaO / SrO of 0 to 10 , A mass ratio SiO ₂ / SrO of 1 to 10, and a mass ratio (MgO + CaO) / SrO of 0 to 5.

(3) SiO ₂ 35~50% in mass% as a glass _{composition, B 2 O 3 0~3%,} CaO 0~9%, SrO 2~20%, BaO 0~28%, ZnO 0~1%, ZrO ₂ + TiO ₂ 3 to 15%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 0.1%, Li ₂ O + Na ₂ O + K ₂ O 0 to 0.1%, and a mass ratio BaO / SrO of 0 to 8 , A mass ratio SiO ₂ / SrO of 2 to 10, and a mass ratio (MgO + CaO) / SrO of 0 to 3.

(4) SiO ₂ 35~50% in mass% as a glass _{composition, B 2 O 3 0~1%,} CaO 0~8.5%, SrO 4~15%, BaO 0~28%, ZnO 0~0.1%, ZrO ₂ + TiO ₂ 6 to 15%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 0.1%, Li ₂ O + Na ₂ O + K ₂ O 0 to 0.1%, and a mass ratio BaO / SrO of 0 to 8 , A mass ratio SiO ₂ / SrO of 2 to 10, and a mass ratio (MgO + CaO) / SrO of 0 to 3.

_{(5) SiO 2 35~55%,} B 2 O 3 0~8%, SrO 0.001~35%, ZnO 0~12%, ZrO 2 + TiO 2 0.001~30%, La 2 O 3 + Nb 2 O 5 _{0~5%, Li 2 O + Na} 2 O + K 2 O containing 0 - 10%, and the mass ratio BaO / SrO is 0 to 20, the weight ratio SiO ₂ / SrO is from 0.1 to 20, the mass ratio (CaO + MgO) / SrO is 0-20.

(6) SiO ₂ 35~55% in mass% as a glass _{composition, B 2 O 3 0~5, MgO} 0~5%, ZrO 2 0~10%, Li 2 O + Na 2 O + K 2 O 0~ , BaO 0 to 30%, TiO ₂ 0.001 to 15%, La ₂ O ₃ + Nb ₂ O ₅ + Gd ₂ O ₃ 0 to 9%, and a mass ratio (La ₂ O ₃ + Nb ₂ O ₅ ) / (ZrO ₂ + TiO ₂ ) is 0 to 5, and the mass ratio of BaO / SrO is 0 to 10.

(7) A glass composition comprising 35 to 55% SiO ₂ , 0 to 5% B ₂ O _3, 0 to 5% MgO, 0 to 10% ZrO ₂ , Li ₂ O + Na ₂ O + K ₂ O 0 ~2%, SrO 0.1~20%, BaO 0~30%, TiO 2 0.001~15%, La 2 O 3 + Nb 2 O 5 + Gd contain ₂ O ₃ 0~9%, the mass ratio (La ₂ O _{3 + Nb 2 O 5) /} (ZrO 2 + TiO 2) is 0 to 5, weight ratio of BaO / SrO is 0 to 10, a weight ratio SiO ₂ / SrO 0.1~10, the mass ratio (CaO + MgO) / SrO is 0 to 2.

In the high refractive index glass of the first embodiment, the refractive index nd is 1.55 or more, preferably 1.58 or more, 1.6 or more, 1.63 or more, 1.65 or more, particularly 1.66 or more. When the refractive index nd is less than 1.55, the reflectance at the ITO-glass interface becomes high and the light can not be drawn efficiently. On the other hand, if the refractive index nd exceeds 2.3, the reflectance at the air-glass interface becomes high, so that even if the surface of the glass is roughened, it becomes difficult to increase the light extraction efficiency. Therefore, the refractive index nd is preferably 2.3 or less, 2.2 or less, 2.1 or less, 2.0 or less, 1.9 or less, particularly 1.75 or less.

In the high refractive index glass of 1st Embodiment, liquidus temperature is 1200 degrees C or less, 1150 degrees C or less, 1130 degrees C or less, 1110 degrees C or less, 1090 degrees C or less, 1070 degrees C or less, especially 1050 degrees C or less is preferable. Further, the liquidus viscosity is 10 ^3.0 dPa · s or more, 10 ^3.5 dPa · s or more, 10 ^3.8 dPa · s or more, 10 ^4.0 dPa · s or more, 10 ^4.1 dPa · s or more, 10 ^4.2 dPa · s or more, in particular 10 ^4.3 dPa s or more is preferable. This makes it difficult for the glass to devitrify at the time of molding, and the glass sheet can be easily formed by the float method.

The high-refractive-index glass of the first embodiment is preferably in the form of a plate. The 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, and particularly 0.2 mm or less. The smaller the plate thickness, the higher the flexibility and easier the design of the lighting device. However, if the plate thickness is extremely small, the glass plate is liable to be damaged. Therefore, the plate thickness is preferably 10 占 퐉 or more, particularly preferably 30 占 퐉 or more.

The high refractive index glass of the first embodiment is preferably formed by a float method. By doing so, a glass plate having good surface quality with unburned metal is inexpensive and can be mass-produced.

As a method of forming a glass plate in addition to the float method, for example, a down-draw method (overflow down-draw method, slot-down draw method, lead-down method, etc.), roll-

The high refractive index glass of the first embodiment is preferably subjected to a roughening treatment on one side by HF etching, sandblasting 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, particularly preferably 50 angstroms or more. If the roughened surface is made to be in contact with air such as organic EL lighting, the roughened surface becomes a non-reflective structure, so that light generated in the organic luminescent layer is difficult to return to the organic luminescent layer. In addition, a concavo-convex shape may be imparted to the glass surface by thermal processing such as repressing. In this way, an accurate reflection structure can be formed on the glass surface. The irregular shape may be adjusted by adjusting the interval and the depth while taking the refractive index nd into account. Further, a resin film having a concavo-convex shape may be attached to the glass surface.

When the atmospheric pressure plasma process is employed, it is possible to uniformly perform the roughening treatment on the other surface while maintaining the surface state of one surface. It is also 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, the plasma containing the HF-based gas is generated, thereby improving the efficiency of the roughening treatment.

Further, in the case of forming an anti-reflection structure on the glass surface at the time of molding, the same effect can be enjoyed without roughening treatment.

In the high refractive index glass of the first embodiment, the density is 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 / desirable. By doing so, the weight of the glass can be reduced and the device can be made lighter. The &quot; density &quot; can be measured by the well-known Archimedes method.

The high refractive index in the glass of the first embodiment, the thermal expansion coefficient is ^{30 × 10 -7 ~100 × 10 -7} / ℃, 40 × 10 -7 ~90 × 10 -7 / ℃, 60 × 10 -7 ~85 × the ^{10 -7 / ℃, 65 × 10} -7 ~80 × 10 -7 / ℃, 68 × 10 -7 ~78 × 10 -7 / ℃, especially ^{70 × 10 -7 ~78 × 10 -7} / ℃ preferably Do. In recent years, a flexible glass plate has been required from the viewpoint of improving design elements in organic EL lighting, organic EL devices, and dye-sensitized solar cells. In order to increase the flexibility of the glass plate, it is necessary to reduce the thickness of the glass plate. However, in this case, if the thermal expansion coefficient of the glass plate and the transparent conductive film such as ITO or FTO is incompatible, Further, when the organic EL display using the oxide TFT is manufactured, if the thermal expansion coefficient of the oxide TFT and the glass plate is inconsistent, warpage may occur in the glass plate or cracks may occur in the oxide TFT film. Therefore, if the coefficient of thermal expansion is set within the above range, such a situation can be easily prevented. Here, the &quot; thermal expansion coefficient &quot; refers to an average value in a temperature range of 30 to 380 DEG C, and can be measured by, for example, a dilatometer or the like.

In the high refractive index glass of the first embodiment, the distortion point is preferably 630 DEG C or higher, 650 DEG C or higher, 670 DEG C or higher, 690 DEG C or higher, particularly 700 DEG C or higher. This makes it difficult for the glass to shrink by heat treatment at a high temperature in the manufacturing process of the device. Particularly, when an organic EL display is manufactured using an oxide TFT or the like, a heat treatment at about 600 ° C is required to stabilize the quality of the oxide TFT. However, as described above, the heat shrinkage of the glass in the heat treatment is reduced .

In the high refractive index glass of the first embodiment, the temperature at 10 ^2.5 dPa 는 is preferably 1400 캜 or lower, 1350 캜 or lower, 1300 캜 or lower, 1250 캜 or lower, particularly 1200 캜 or lower. This improves the melting property, so that it is easy to obtain a glass having an excellent foam quality and the production efficiency of the glass plate is improved.

In the high refractive index glass of the first embodiment, the temperature at 10 ^4.0 dPa · s is 1250 ° C or lower, 1200 ° C or lower, 1150 ° C or lower, 1110 ° C or lower, particularly 1060 ° C or lower. By doing so, it becomes possible to lower the molding temperature in the molding by the float method. As a result, low-temperature operation becomes possible, the refractory used in the molding part becomes long, and the manufacturing cost of the glass plate tends to be lowered.

[0041] As an example of the manufacturing method of the high-refractive-index glass of the first embodiment, a glass batch is produced by combining glass raw materials so as to have a desired glass composition. Subsequently, the glass batch is melted and refined, and the obtained molten glass is molded into a desired shape. Thereafter, annealing is carried out according to necessity, and a desired shape is formed.

The glass plate for an illumination device according to the first aspect of the present invention is characterized in that the glass composition contains 0.1 to 60% of SiO ₂ , 0 to 10% of B ₂ O ₃ , 0.001 to 35% of SrO, 0 to 40% of BaO, ₂ + TiO ₂ 0.001 to 30%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 10%, and a refractive index nd of 1.55 to 2.3. Further, the glass plate for organic EL lighting according to the first aspect of the invention is characterized in that the glass composition contains 0.1 to 60% of SiO ₂ , 0 to 10% of B ₂ O ₃ , 0.001 to 35% of SrO, 0 to 40% of BaO, ₂ + TiO ₂ 0.001 to 30%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 10%, and a refractive index nd of 1.55 to 2.3. The glass plate for an organic EL display according to the first aspect of the invention has a composition of 0.1 to 60% of SiO ₂ , 0 to 10% of B ₂ O ₃ , 0.001 to 35% of SrO, 0 to 40% of BaO, 0.001 to 30% of ZrO ₂ + TiO ₂ , 0 to 10% of La ₂ O ₃ + Nb ₂ O ₅ , and a refractive index nd of 1.55 to 2.3. The technical features of the glass plate for an illumination device, the glass plate for an organic EL lighting, and the glass plate for an organic EL display are substantially the same as those of the high refractive index glass described in the first embodiment, and therefore a detailed description thereof will be omitted.

Example 1

Hereinafter, embodiments of the first invention will be described in detail. In addition, the following embodiment is a mere illustration. The first invention is not limited to the following embodiments.

Tables 1 to 4 show Examples (Sample Nos. 1 to 19) of the first invention.

First, the glass raw materials were combined so as to obtain the glass compositions shown in Tables 1 to 4, and the obtained glass batches were supplied to a glass melting furnace and melted at 1500 to 1600 占 폚 for 4 hours. Subsequently, the obtained molten glass was flowed out onto a carbon plate, molded into a plate shape, and then subjected to predetermined annealing. Finally, various properties of the obtained glass plate were evaluated.

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

The coefficient of thermal expansion is a value obtained by measuring an average thermal expansion coefficient at 30 to 380 ° C using a dilatometer. As a measurement sample, a cylindrical sample of φ5 mm × 20 mm (R end surface was processed) was used.

The point Ps is a value measured by the method described in ASTM C336-71. Further, the higher the Ps point, the higher the heat resistance.

The standing 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 揃 s, 10 ^3.0 dPa 揃 s, and 10 ^2.5 dPa 揃 s are values measured by a platinum spherical impression method. Further, the lower the temperature, the better the melting property.

The liquidus temperature TL is a value obtained by passing glass powder passing through a standard 30 mesh (500 mu m) and remaining in 50 mesh (300 mu m) into a platinum boat and holding it in a temperature gradient for 24 hours to measure the temperature at which crystals are precipitated. The logarithmic viscosity log ₁₀ ηTL indicates a value obtained by measuring the viscosity of the glass at the liquidus temperature by the platinum spherical impression method. Further, the higher the liquid phase viscosity and the lower the liquid phase temperature, the better the resistance to devitrification and moldability.

The refractive index nd was prepared by first preparing a rectangular parallelepiped sample having a size of 25 mm x 25 mm x approximately 3 mm and then annealing the glass substrate at a cooling rate of 0.1 deg. C / min at a temperature range of (Ta point + 30 deg. C) And then measured with a refractive index measuring instrument KPR-2000 of Shimadzu Seisakusho Co., Ltd., while infiltrating the submerged solution with the refractive index nd into the glass.

[Example 2]

After the glass raw materials were combined so as to obtain the glass composition described in Sample No. 3, the obtained glass batches were put into a continuous kiln and melted at a temperature of 1500 to 1600 ° C. Subsequently, the obtained molten glass was molded by the float method to obtain a glass plate having a thickness of 0.5 mm.

After the glass raw materials were combined so as to obtain the glass composition described in sample No. 4, the obtained glass batches were put into a continuous kiln and melted at a temperature of 1500 to 1600 ° C. Subsequently, the obtained molten glass was molded by the float method to obtain a glass plate having a thickness of 0.5 mm.

After the glass raw materials were combined to obtain the glass composition described in Sample No. 6, the obtained glass batches were put into a continuous kiln and melted at a temperature of 1500 to 1600 ° C. Subsequently, the obtained molten glass was molded by the float method to obtain a glass plate having a thickness of 0.5 mm.

&Lt; Second Embodiment >

The high-by (hereinafter referred to as second embodiment), the embodiment of the second aspect of the present invention the refractive index of glass is SiO _2, 30~60% in mass% as a glass _{composition, B 2 O 3 0~15%,} Al 2 O 3 0~ _{15%, Li 2 O 0~10%} , Na 2 O 0~10%, K 2 O 0~10%, MgO + CaO + SrO + BaO + ZnO 20~60%, TiO 2 0.0001~20%, ZrO 2 0 to 20%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 10%. The reasons for limiting the content range of each component as described above will be explained below. In addition, unless otherwise stated in the description of the content range of each component,% represents mass%.

The content of SiO ₂ is 30 to 60%. When the content of SiO ₂ is increased, the meltability and moldability are likely to be lowered, and the refractive index nd is likely to be lowered. Therefore, the upper limit of the content of SiO ₂ is 60% or less, preferably 50% or less, 48% or less, 45% or less, particularly 43% or less. On the other hand, if the content of SiO ₂ is decreased, it becomes difficult to form a glass network structure, and vitrification becomes difficult. Further, the viscosity of the glass is excessively lowered, so that it becomes difficult to secure a high liquid-phase viscosity, and the acid resistance tends to be lowered. Therefore, the lower limit of the content of SiO ₂ is at least 30%, preferably at least 35%, at least 38%, especially more than 40%.

The content of B ₂ O ₃ is 0 to 15%. As the content of B ₂ O ₃ increases, the Young's modulus tends to be lowered, and the point of the cause is likely to be lowered. Further, the balance of components in the glass composition is impaired, and resistance to insolubility tends to be lowered, and the acid resistance tends to be lowered. Therefore, the upper limit of the content of B ₂ O ₃ is 15% or less, preferably 10% or less, 8% or less, particularly 6% or less. On the other hand, when the content of B ₂ O ₃ is decreased, the glass liquid phase viscosity tends to decrease. Therefore, the lower limit content of B ₂ O ₃ is preferably 0.1% or more, 0.5% or more, 1% or more, 1.5% or more, 2% or more, 3% or more, and especially 4% or more.

The mass ratio B ₂ O ₃ / SiO ₂ is preferably 0 to 1. When the mass ratio B ₂ O ₃ / SiO ₂ is increased, it becomes difficult to ensure a high liquid-phase viscosity and the chemical resistance tends to be deteriorated. Therefore, the upper limit of the preferable range of the mass ratio B ₂ O ₃ / SiO ₂ is 1 or less, 0.5 or less, 0.2 or less, 0.15 or less, particularly 0.13 or less. On the other hand, when the mass ratio B ₂ O ₃ / SiO ₂ becomes smaller, the balance of components of the glass composition is impaired and the resistance to devitrification tends to decrease. Therefore, the preferred lower limit of the mass ratio B ₂ O ₃ / SiO ₂ is 0.01 or more, 0.02 or more, 0.03 or more, 0.04 or more, 0.05 or more, and especially 0.10 or more.

The content of Al ₂ O ₃ is 0 to 15%. If the content of Al ₂ O ₃ is excessively large, the balance of components of the glass composition is impaired and the resistance to devitrification tends to be reduced. In addition, the acid resistance tends to decrease. Therefore, the upper limit of the content of Al ₂ O ₃ is 15% or less, preferably 10% or less, 8% or less, particularly 6% or less. On the other hand, when the content of Al ₂ O ₃ is decreased, the viscosity of the glass is excessively lowered, and it becomes difficult to secure a high liquid viscosity. Therefore, the lower limit content of Al ₂ O ₃ is preferably 0.5% or more, 1% or more, 2% or more, particularly 4% or more.

The content of Li ₂ O is 0 to 10%. When the content of Li ₂ O is increased, the liquid phase viscosity tends to be lowered, and the point of the cause is easily lowered. In addition, in the etching step with an acid, the glass is liable to be clouded by the elution of the alkali component. Therefore, the upper limit of the content of Li ₂ O is 10% or less, preferably 8% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, especially 1% or less, It is preferable that it is not contained. Here, "substantially not containing Li ₂ O" refers to a case where the content of Li ₂ O in the glass composition is less than 1000 ppm (mass).

The content of Na ₂ O is 0 to 10%. If the content of Na ₂ O is increased, the liquid phase viscosity tends to be lowered, and the point of the cause is likely to be lowered. In addition, in the etching step with an acid, the glass is liable to be clouded by the elution of the alkali component. Therefore, the upper limit of the content of Na ₂ O is 10% or less, preferably 8% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, It is preferable that it is not contained. Here, &quot; substantially not containing Na ₂ O &quot; indicates a case where the content of Na ₂ O in the glass composition is less than 1000 ppm (mass).

The content of K ₂ O is 0 to 10%. When the content of K ₂ O is increased, the liquid phase viscosity tends to be lowered, and the point of the cause is likely to be lowered. In addition, in the etching step with an acid, the glass is liable to be clouded by the elution of the alkali component. Therefore, the upper limit of the content of K ₂ O is 10% or less, preferably 8% or less, 5% or less, 4% or less, 3% or less, 2% or less, 1% or less, especially 1% or less, It is preferable that it is not contained. Here, "substantially free of K ₂ O" refers to a case where the content of K ₂ O in the glass composition is less than 1000 ppm (mass).

The content of Li ₂ O + Na ₂ O + K ₂ O is preferably 0 to 10%. When the content of Li ₂ O + Na ₂ O + K ₂ O is increased, the liquid phase viscosity tends to be lowered and the point of the cause is easily lowered. In addition, in the etching step with an acid, the glass is liable to be clouded by the elution of the alkali component. Therefore, the upper limit of the content of Li ₂ O + Na ₂ O + K ₂ O is 10% or less, 8% or less, 5% or less, 4% or less, 3% or less, 2% or less, And it is preferable that it is substantially not contained. Herein, it refers to a "substantially Li ₂ O + Na ₂ O + K ₂ O does not contain" means the glass composition of Li ₂ O + Na ₂ O + K ₂ O content of the 1000ppm (by weight) of less than.

The content of MgO is preferably 0 to 20%. MgO is a component that increases refractive index nd, Young's modulus, and fulcrum, and lowers the high-temperature viscosity. However, when MgO is contained in a large amount, there is a fear that the liquidus temperature rises and the resistance to devitrification lowers or the density and thermal expansion coefficient become too high. Therefore, the upper limit content of MgO is preferably 20% or less, 10% or less, particularly 6% or less. On the other hand, when the content of MgO is decreased, the meltability is lowered, the Young's modulus is lowered, and the refractive index nd is likely to be lowered. Therefore, the lower limit of the content of MgO is preferably 0.1% or more, 0.5% or more, 1% or more, 1.5% or more, 2% or more, and particularly 3% or more.

The content of CaO is preferably 0 to 15%. When the content of CaO is increased, the density and the thermal expansion coefficient are liable to be high, and the balance of components of the glass composition is impaired, and the resistance to devitrification tends to decrease. Therefore, the upper limit content of CaO is preferably 15% or less, 13% or less, 11% or less, 9.5% or less, particularly 8% or less. On the other hand, when the content of CaO is decreased, the meltability is lowered, the Young's modulus is lowered, and the refractive index nd is easily lowered. Therefore, the lower limit content of CaO is preferably 0.5% or more, 1% or more, and especially 2% or more.

As for content of SrO, 0-25% is preferable. When the content of SrO is increased, the refractive index nd, the density and the thermal expansion coefficient are liable to be high, and the balance of components of the glass composition is impaired, and the resistance to devitrification tends to decrease. Therefore, the upper limit content of SrO is preferably 25% or less, 18% or less, 14% or less, particularly 12% or less. On the other hand, if the content of SrO is small, the meltability tends to be lowered, and the refractive index nd tends to be lowered. Therefore, the lower limit of the content of SrO is preferably 0.1% or more, 0.5% or more, 1% or more, 2% or more, 5% or more, 7% or more, and especially 9% or more.

Among alkaline earth metal oxides, BaO is a component that increases the refractive index nd without extremely lowering the viscosity of the glass, and its content is preferably 0.1 to 60%. When the content of BaO is increased, the refractive index nd, the density and the thermal expansion coefficient are liable to be high, and the balance of components of the glass composition is impaired, and the resistance to devitrification tends to decrease. Therefore, the upper limit of the content of BaO is preferably 60% or less, 53% or less, 48% or less, 44% or less, 40% or less, 39% or less, 36% or less, 35% or less, 34% or less, On the other hand, when the content of BaO is decreased, it becomes difficult to obtain a desired refractive index nd and it becomes difficult to secure a high liquid viscosity. Accordingly, the upper limit of the content of BaO is preferably 0.1% or more, 1% or more, 2% or more, 5% or more, 10% or more, 15% or more, 20% or more, 23% or more, and particularly 25% or more.

The content of ZnO is preferably 0 to 20%. ZnO is a component that increases the refractive index nd and the dull point, and lowers the high temperature viscosity. However, when a large amount of ZnO is added, the liquid phase temperature rises and the resistance to devitrification tends to decrease, and the density and the thermal expansion coefficient may become too high. Therefore, the upper limit content of ZnO is preferably 20% or less, 10% or less, 5% or less, 3% or less, particularly 1% or less.

The content of MgO + CaO + SrO + BaO + ZnO is 20 to 60%. When the content of MgO + CaO + SrO + BaO + ZnO is increased, the density and the thermal expansion coefficient are liable to increase, and the balance of components of the glass composition is impaired, and resistance to devitrification tends to decrease. Therefore, the upper limit of the content of MgO + CaO + SrO + BaO + ZnO is 60% or less, preferably 55% or less, 50% or less, 48% or less, particularly 45% or less. On the other hand, when the content of MgO + CaO + SrO + BaO + ZnO is decreased, the glass becomes unstable. Therefore, the lower limit of the content of MgO + CaO + SrO + BaO + ZnO is 20% or more, preferably 30% or more, 35% or more, particularly 40% or more.

TiO ₂ is a component that increases the refractive index nd. The content of TiO ₂ is 0.0001 to 20%. However, when the content of TiO ₂ is increased, the balance of the components of the glass composition is impaired and the resistance to devitrification tends to be lowered. In addition, the transmittance is decreased, and when applied to an organic EL display, the luminous efficiency may be lowered. Therefore, the upper limit of the content of TiO ₂ is 20% or less, preferably 10% or less, 7% or less, particularly 5% or less. On the other hand, if the content of TiO ₂ is decreased, it becomes difficult to obtain a desired refractive index nd. Therefore, the lower limit of the content of TiO ₂ is 0.0001% or more, preferably 0.001% or more, 0.01% or more, 0.02% or more, 0.05% or more, 0.1% or more, 1% or more, and particularly 2% or more.

ZrO ₂ is a component that increases the refractive index nd. The content of ZrO ₂ is 0 to 20%. However, when the content of ZrO ₂ is increased, the balance of components of the glass composition is impaired and the resistance to devitrification tends to decrease. Therefore, the upper limit of the content of ZrO ₂ is 20% or less, preferably 10% or less, 7% or less, particularly 5% or less. On the other hand, if the content of ZrO ₂ is decreased, it becomes difficult to obtain a desired refractive index nd. Therefore, the lower limit of the content of ZrO ₂ is preferably 0.0001% or more, more preferably 0.001% or more, 0.01% or more, 0.02% or more, 0.05% or more, 0.1% or more, 1% or more and especially 2% or more.

La ₂ O ₃ is a component that increases the refractive index nd. The content of La ₂ O ₃ is preferably 0 to 10%. When the content of La ₂ O ₃ is increased, the density and thermal expansion coefficient are liable to be increased, and resistance to devitrification and acid resistance are likely to be lowered. Further, the cost of the raw material is increased, and the manufacturing cost of the glass plate is likely to increase. Therefore, the upper limit content of La ₂ O ₃ is preferably 10% or less, 5% or less, 3% or less, 2.5% or less, particularly 1% or less.

Nb ₂ O ₅ is a component that increases the refractive index nd. The content of Nb ₂ O ₅ is preferably 0 to 10%. When the content of Nb ₂ O ₅ is increased, the density and the thermal expansion coefficient are liable to be increased, and the resistance to devitrification tends to decrease. Further, the cost of the raw material is increased, and the manufacturing cost of the glass plate is likely to increase. Therefore, the upper limit content of Nb ₂ O ₅ is preferably 10% or less, 5% or less, 3% or less, particularly 1% or less.

The content of Gd ₂ O ₃ is preferably 0 to 10%. Gd ₂ O ₃ is a component that increases the refractive index nd. However, if the content of Gd ₂ O ₃ is increased, the density and the thermal expansion coefficient become excessively high, the component balance of the glass composition is lost, and the resistance to devitrification tends to deteriorate, and the high-temperature viscosity tends to be too low. Therefore, the upper limit content of Gd ₂ O ₃ is preferably 10% or less, 5% or less, 3% or less, particularly 1% or less.

The content of La ₂ O ₃ + Nb ₂ O ₅ is 0 to 10%. When the content of La ₂ O ₃ + Nb ₂ O ₅ is increased, the density and thermal expansion coefficient are liable to be increased, the resistance to devitrification tends to be lowered, and it is difficult to secure a high liquid viscosity. Further, the cost of the raw material is increased, and the manufacturing cost of the glass plate is likely to increase. Therefore, the upper limit of the content of La ₂ O ₃ + Nb ₂ O ₅ is 10% or less, preferably 8% or less, 5% or less, 3% or less, 1% or less, 0.5% or less, particularly 0.1% or less.

The content of the rare metal oxide is preferably 0 to 10% by mass. If the content of the rare metal oxide is large, the density and the thermal expansion coefficient are likely to be high, and resistance to devitrification and acid resistance tends to be deteriorated, and it becomes difficult to secure a high liquid viscosity. Further, the cost of the raw material is increased, and the manufacturing cost of the glass plate is likely to increase. Therefore, the upper limit content of the rare metal oxide is preferably 10% or less, 5% or less, 3% or less, particularly 1% or less.

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

As the clarifying agent, 0 to 3% of one or more selected from the group consisting of As ₂ O ₃ , Sb ₂ O ₃ , CeO ₂ , SnO ₂ , F, Cl and SO ₃ may be added. However, As ₂ O ₃ , Sb ₂ O ₃ and F are preferably avoided from the viewpoint of environment, and the content of each is preferably less than 0.1%. In view of the above, SnO ₂ , SO ₃ , Cl, and CeO ₂ are preferable as the fining agent.

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

The content of SO ₃ is preferably 0 to 1%, 0 to 0.5%, 0.001 to 0.1%, 0.005 to 0.1%, 0.01 to 0.1%, particularly 0.01 to 0.05%. Sodium sulfate may be used as a raw material for introducing SO ₃ . Further, a raw material containing sulfuric acid may be used.

The content of Cl is preferably 0 to 1%, 0.001 to 0.5%, particularly 0.01 to 0.4%.

The content of SnO ₂ + SO ₃ + Cl is preferably 0 to 1%, 0.001 to 1%, 0.01 to 0.5%, particularly 0.01 to 0.3%. Here, &quot; SnO ₂ + SO ₃ + Cl &quot; refers to the sum of SnO ₂ , SO ₃ , and Cl.

The content of CeO ₂ is preferably 0 to 6%. When the content of CeO ₂ is increased, resistance to devitrification tends to decrease. Therefore, the upper limit content of CeO ₂ is preferably 6% or less, 5% or less, 3% or less, 2% or less, particularly 1% or less. On the other hand, if CeO ₂ is less, the effect as a refining agent becomes insufficient. Therefore, the lower limit content of CeO ₂ is preferably 0.001% or more, 0.005% or more, 0.01% or more, 0.05% or more, particularly 0.1% or more.

PbO is a component that lowers the high-temperature viscosity, but it is preferable to avoid its use from the environmental viewpoint as much as possible. The content of PbO is preferably 0.5% or less, and is preferably substantially free of PbO. Here, &quot; substantially free of PbO &quot; means a case where the content of PbO in the glass composition is less than 1000 ppm (mass).

It is possible to construct a preferable glass composition range by combining the preferable content ranges of the respective components. Among them, preferable glass composition ranges are as follows.

(1) 30 to 60% of SiO ₂ , 0 to 15% of B ₂ O _3, 0 to 15% of Al ₂ O _3, 0 to 10% of Li ₂ O, 0 to 10% of Na ₂ O, K ₂ O containing 0~10%, MgO + CaO + SrO + BaO + ZnO 20~60%, TiO 2 0.1~20%, ZrO 2 0~20%, La 2 O 3 + Nb 2 O 5 0~10%,

(2) in _{mass% SiO 2 35~45%, B 2} O 3 2~8%, Al 2 O 3 4~8%, Li 2 O 1~8%, Na 2 O 0~5%, K 2 O 0 to 8%, MgO + CaO + SrO + BaO + 30 to 48% ZnO, 1 to 7% TiO ₂ , 0.1 to 5% ZrO _{2 and 0 to} 5% La ₂ O ₃ + Nb ₂ O ₅ .

In the high refractive index glass of the second embodiment, the refractive index nd is 1.55 or more, preferably 1.58 or more, 1.60 or more, particularly 1.63 or more. If the refractive index nd is less than 1.55, light can not be efficiently drawn out due to reflection at the interface between the transparent conductive film and the glass plate. On the other hand, if the refractive index nd is higher than 2.3, the reflectance at the air-glass plate interface becomes high, so that even if the surface of the glass is roughened, it becomes difficult to draw out the light to the outside. Therefore, the refractive index nd is 2.3 or less, preferably 2.2 or less, 2.1 or less, 2.0 or less, 1.9 or less, particularly 1.75 or less.

In the high refractive index glass of the second embodiment, 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 / Or less, particularly 3.4 g / cm 3 or less. In this way, the device can be made lighter.

In the high refractive index glass of the second embodiment, the coefficient of thermal expansion at 30 to 380 ° C is preferably 45 × 10 ^{-7 to} 110 × 10 ^-7 / ° C., 50 × 10 ^{-7 to} 100 × 10 ^-7 / ^{℃, 60 × 10 -7 ~95 ×} 10 -7 / ℃, 65 × 10 -7 ~90 × 10 -7 / ℃, 65 × 10 -7 ~85 × 10 -7 / ℃, especially 67 × 10 ^-7 To 80 x 10 &lt; ^-7 &gt; / [deg.] C. In recent years, flexibility is imparted to a glass plate from the viewpoint of improving the design factor in organic EL devices and the like. In order to increase the flexibility of the glass plate, it is necessary to reduce the thickness of the glass plate. In this case, if the thermal expansion coefficient of the glass plate and the transparent conductive film are incompatible, the glass plate is liable to bend. Therefore, if the coefficient of thermal expansion at 30 to 380 ° C falls within the above range, such a situation can be easily prevented.

In the high refractive index glass of the second embodiment, the distortion point is preferably 600 占 폚 or higher, particularly 630 占 폚 or higher. In a device such as an organic thin-film solar cell, when the transparent conductive film is formed, the film can be formed with a high transparency and a low electrical resistance as the film is processed at a high temperature. However, the conventional high refractive index glass is insufficient in heat resistance, so that it is difficult to achieve both transparency and low electrical resistance. Therefore, when the point of the defect is within the above-mentioned range, both transparency and low electrical resistance can be achieved in a device such as an organic thin film solar cell, and the heat shrinkage of the glass becomes difficult due to the heat treatment in the device manufacturing process.

In the high refractive index glass of the second embodiment, the temperature at 10 ^2.5 dPa s is preferably 1450 캜 or lower, 1400 캜 or lower, 1350 캜 or lower, 1300 캜 or lower, 1250 캜 or lower, particularly 1200 캜 or lower. This improves the melting efficiency, thus improving the production efficiency of the glass.

In the high refractive index glass of the second embodiment, the liquidus temperature is preferably 1200 占 폚 or lower, 1150 占 폚 or lower, 1130 占 폚 or lower, 1110 占 폚 or lower, 1090 占 폚 or lower, 1070 占 폚 or lower, 1050 占 폚 or lower, Lt; 0 &gt; C or less, particularly 980 &lt; 0 &gt; The liquid viscosity is preferably at least 10 ^3.5 dPa · s, at least 10 ^3.8 dPa · s, at least 10 ^4.0 dPa · s, at least 10 ^4.2 dPa · s, at least 10 ^4.4 dPa · s, at least 10 ^4.6 dPa · s, 10 ^4.8 dPa · s or more, particularly 10 ^5.0 dPa · s or more. This makes it difficult for the glass to devitrify at the time of molding, and the glass sheet can be easily formed by the float method or the overflow down-draw method.

The high refractive index glass of the second embodiment is preferably in the form of a plate. The thickness (plate thickness in the case of a plate shape) 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, Mm or less. The smaller the thickness, the higher the flexibility and the easier the production of an illumination device with excellent design. However, if the thickness is extremely small, the glass tends to be broken. Therefore, the thickness is preferably 10 占 퐉 or more, particularly 30 占 퐉 or more.

In the case of the plate-shaped high-refractive-index glass of the second embodiment, it is preferable that at least one surface has a surface that is not polished (in particular, the entire effective surface of at least one surface is unmelted). Although the theoretical strength of the glass is very high in the beginning, it is often the case that even with a stress much lower than the theoretical strength, the glass is destroyed. This is because a small defect called Griffith's flaw on the glass surface occurs in a post-molding process, for example, a polishing process. Therefore, if the glass surface is not smoothened, it is difficult to impair the mechanical strength of the original glass, so that the glass is hardly destroyed. In addition, since the polishing step can be simplified or omitted, the manufacturing cost of the glass plate can be reduced.

In the high refractive index glass of the second embodiment, the surface roughness Ra of the surface of the unpolished surface is preferably 10 angstroms or less, 5 angstroms or less, 3 angstroms or less, particularly 2 angstroms or less. When the surface roughness Ra is larger than 10 angstroms, the quality of the transparent conductive film formed on the surface is lowered, and it becomes difficult to obtain uniform light emission.

It is preferable that the high-refractive-index glass of the second embodiment is formed by a down-draw method, particularly an over-flow down-draw method. In this way, a glass plate with favorable surface quality can be manufactured by unpolishing. This is because, in the case of the overflow down-draw method, the surface to be the surface does not contact the gutter-type refractory, but is formed in the state of the free surface. The structure and material of the trough-shaped structure are not particularly limited as long as the desired dimensions and surface precision can be realized. There is also no particular limitation on a method of applying a force to the molten glass in order to perform downward stretch molding. For example, a method in which a heat resistant roll having a sufficiently large width is rotated while being in contact with the molten glass may be adopted, or a method in which a plurality of pairs of heat resistant rolls are drawn in contact with only the vicinity of the end face of the molten glass Maybe. In addition to the overflow down-draw method, the slot-down draw method can be employed as the down-draw method. This makes it easier to produce a glass sheet having a small sheet thickness. Here, the &quot; slot-down draw method &quot; is a method of forming a glass sheet by drawing down the molten glass from a substantially rectangular gap while downwardly forming the molten glass.

The high refractive index glass of the second embodiment is preferably formed by a float method. In this way, a large-sized glass plate can be manufactured at a low cost and in a large quantity.

In addition to the above-described forming method, for example, a reedrow method, a float method, a roll-out method, or the like can be employed.

The high refractive index glass of the second embodiment is preferably subjected to a roughening treatment on one side by HF etching, sandblasting 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, particularly 50 angstroms or more. If the roughened surface is made to be in contact with air such as organic EL lighting, the roughened surface becomes a non-reflective structure, so that light generated in the organic luminescent layer is difficult to return to the organic luminescent layer. It is also possible to impart a concavo-convex shape to the glass surface (for example, thermal processing such as repressing). In this way, an accurate reflection structure can be formed on the glass surface. The irregular shape may be adjusted by adjusting the interval and the depth while taking the refractive index nd into account. Further, a resin film having a concavo-convex shape may be attached to the glass surface.

In addition, when the roughening treatment is performed by the atmospheric pressure plasma process, roughening treatment can be uniformly performed on the other surface while maintaining the surface condition of one surface. It is also preferable to use a gas containing F (for example, SF ₆ , CF ₄ ) as a source of the atmospheric pressure plasma process. In this case, the plasma containing the HF-based gas is generated, thereby improving the efficiency of the roughening treatment.

It is also preferable to form a concavo-convex shape on one side at the time of molding. In this case, the separate surface roughening process is not required, and the efficiency of the surface roughening process is improved.

Next, a method of manufacturing the high refractive index glass of the second embodiment will be illustrated. First, a glass batch is produced by combining glass raw materials so as to have a desired glass composition. Then, the glass batch is melted and refined, and then molded into a desired shape. After that, it is processed into a desired shape.

[Example 3]

Hereinafter, an embodiment of the second invention will be described in detail. In addition, the following embodiment is a mere illustration. The second invention is not limited to the following embodiments.

Tables 5 to 12 show Examples (Sample Nos. 20 to 55) and Comparative Examples (Sample No. 56) of the second invention.

First, the glass raw materials were combined so as to obtain the glass compositions shown in Tables 5 to 12, and the obtained glass batches were supplied to a glass melting furnace and melted at 1500 占 폚 for 4 hours. Subsequently, the obtained molten glass was flowed out onto a carbon plate, molded into a plate shape, and then subjected to predetermined annealing. Finally, various properties of the obtained glass plate were evaluated.

The refractive index nd was prepared by first preparing a rectangular parallelepiped sample having a size of 25 mm x 25 mm x approximately 3 mm and then annealing the glass substrate at a cooling rate of 0.1 deg. C / min at a temperature range of (Ta point + 30 deg. C) And then measured by a refractive index meter KPR-2000 manufactured by Shimadzu Seisakusho Co., Ltd., while infiltrating the submerged solution with the refractive index nd into the glass.

The density is measured by the Archimedes method.

The coefficient of thermal expansion is a value obtained by measuring an average thermal expansion coefficient at 30 to 380 ° C using a dilatometer. As a measurement sample, a cylindrical sample of φ5 mm × 20 mm (R end surface was processed) was used.

The point Ps is a value measured by the method described in ASTM C336-71. Further, the higher the Ps point, the higher the heat resistance.

The standing 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 揃 s, 10 ^3.0 dPa 揃 s, 10 ^2.5 dPa 揃 s, and 10 ^2.0 dPa 揃 s are values measured by a platinum spherical impression method. Further, the lower the temperature, the better the melting property.

The liquidus temperature TL is a value obtained by passing glass powder passing through a standard 30 mesh (500 mu m) and remaining in 50 mesh (300 mu m) into a platinum boat and holding it in a temperature gradient for 24 hours to measure the temperature at which crystals are precipitated. The logarithmic viscosity log ₁₀ ηTL is a value obtained by measuring the viscosity of the glass at the liquidus temperature by the platinum sphere pulling method. Further, the higher the liquid phase viscosity and the lower the liquid phase temperature, the more excellent resistance to devitrification and moldability.

The HCl resistance was evaluated by the following method. First, both surfaces of each glass sample were optically polished, and after masking a part of them, chemical treatment was performed under the following conditions. After the chemical liquid treatment, the mask was removed, and the step difference between the mask part and the erosion part was measured by a surface roughness meter, and the value was referred to as an etching amount. The HCl resistance (erosion amount) was evaluated as &quot; X &quot; when the erosion amount was more than 20 mu m and &quot; O &quot; The HCl resistance (appearance) was evaluated by optically polishing both surfaces of each glass sample and then treating the surface of the glass sample after chemical treatment under the following conditions, observing the surface of the glass sample with naked eyes to see whether it was opaque, rough, Was evaluated as &quot;? &Quot;.

The treatment conditions of HCl resistance (immersed amount) were immersed in a 10 mass% aqueous solution of HCl at 80 ° C for 24 hours, and the treatment conditions of HCl resistance (external appearance) were immersed in a 10 mass% aqueous solution of HCl at 80 ° C for 24 hours.

As clearly shown in the table, the sample Nos. 20 to 55 contained substantially no alkali component and no rare-earth metal oxide, had a refractive index nd of 1.623 or more, and good acid resistance. The sample No. 20, 24, 27 to 37, 39, 43 to 45, and 47 to 55 had a liquid viscosity of 10 ^3.4 dPa · s or more. In addition, the sample Nos. 20 to 31 have a low refractive index nd and are low in density, so that the weight of the device can be reduced. Further, since it is close to the coefficient of thermal expansion of the transparent conductive film, it is expected that warping of the glass sheet can be suppressed. In addition, it is believed that since Sample Nos. 20 to 25 and 27 to 55 have high points, heat shrinkage of the glass in the manufacturing process of the device can be suppressed. On the other hand, Sample No. 56 had high density and low acid resistance because it contained a large amount of rare metal oxide in the glass composition.

(Industrial availability)

The high refractive index glass of the present invention has a refractive index nd of 1.55 or more and a high liquid viscosity. From the viewpoint of the raw material cost, it is possible to remove the rare metal oxide from the glass composition, and from the environmental viewpoint, it is also possible to remove As ₂ O ₃ , Sb ₂ O ₃ and the like from the glass composition. Therefore, the high-refractive-index glass of the present invention is preferable for substrates for organic EL devices, particularly substrates for organic EL lighting. The high-refractive-index glass of the present invention can also be used as a substrate for a flat panel display such as a liquid crystal display, a cover glass of an image sensor such as a charge-coupled device (CCD), a proximity proximity solid-state image sensor (CIS) have.

Claims (32)

B ₂ O ₃ 0 - 10% in mass% as a glass _{composition, SrO 0.001~35%, ZrO 2 +} TiO 2 0.001~30%, La 2 O 3 + Nb 2 O 5 0 - 10% and containing, by mass BaO / SrO is 0 to 40, the weight ratio SiO ₂ / SrO is 0.1 to 40, and the refractive index nd is the high refractive index glass, characterized in that from 1.55 to 2.3. The method of claim 1,
And a liquid viscosity of 10 ^3.0 dPa s or more. 3. The method according to claim 1 or 2,
Refractive index glass. The method of claim 3, wherein
The high refractive index glass formed by the float method. The method according to claim 3 or 4,
The temperature in 10 ⁴ dPa · s is 1250 ° C. or less, High refractive index glass. 6. The method according to any one of claims 1 to 5,
Strain point is 650 degreeC or more, High refractive index glass characterized by the above-mentioned. 7. The method according to any one of claims 1 to 6,
High refractive index glass, used for an illumination device. The method of claim 7, wherein
It is used for organic electroluminescent illumination, The high refractive index glass characterized by the above-mentioned. 7. The method according to any one of claims 1 to 6,
It is used for organic electroluminescent display, The high refractive index glass characterized by the above-mentioned. B ₂ O ₃ 0~8% in mass% as a glass composition, SrO 0.001~35%, ZnO 0~12% , ZrO 2 + TiO 2 0.001~30%, La 2 O 3 + Nb 2 O 5 0~5% , Li ₂ O + Na ₂ O + K ₂ O 0 to 10%, mass ratio BaO / SrO is 0 to 20, mass ratio SiO ₂ / SrO is 0.1 to 20, and mass ratio (MgO + CaO) / SrO is 0 to The refractive index nd is 1.58 or more, the liquid viscosity is 10 ^3.5 dPa * s or more, and the distortion point is 670 degreeC or more, The high refractive index glass characterized by the above-mentioned. 10 to 50% of SiO ₂ , 0 to 8% of B ₂ O _3, 0 to 10% of CaO, 0.001 to 35% of SrO, 0 to 30% of BaO, 0 to 4% of ZnO, ZrO ₂ + TiO _{2 2 to} 30%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 5%, Li ₂ O + Na ₂ O + K ₂ O 0 to ₂ %, a mass ratio BaO / SrO of 0 to 20, ₂ / SrO is 1 to 15, the mass ratio (MgO + CaO) / SrO is 0 to 20, the refractive index nd is 1.6 or more, the liquidus viscosity is 10 ^{4 .0} dPa · s or more, Refractive index glass. In mass% as the glass composition of _{SiO 2 0.1~60%, B 2 O} 3 0~10%, SrO 0.001~35%, BaO 0~40%, ZrO 2 + TiO 2 0.001~30%, La 2 O 3 + Nb containing ₂ O ₅ 0~10%, and further the refractive index nd is a glass sheet for lighting device, characterized in that from 1.55 to 2.3. In mass% as the glass composition of _{SiO 2 0.1~60%, B 2 O} 3 0~10%, SrO 0.001~35%, BaO 0~40%, ZrO 2 + TiO 2 0.001~30%, La 2 O 3 + Nb ₂ O ₅ 0-10%, and refractive index nd is 1.55-2.3, The glass plate for organic electroluminescent illumination characterized by the above-mentioned. In mass% as the glass composition of _{SiO 2 0.1~60%, B 2 O} 3 0~10%, SrO 0.001~35%, BaO 0~40%, ZrO 2 + TiO 2 0.001~30%, La 2 O 3 + Nb containing ₂ O ₅ 0~10%, and further the refractive index nd is a glass plate for an organic EL display, characterized in that from 1.55 to 2.3. SiO ₂ 35~60% in mass% as a glass _{composition, 0~1.5% Li 2 O + Na} 2 O + K 2 O, SrO 0.1~35%, BaO 0~35%, TiO 2 0.001~25%, La 2 O ₃ + Nb ₂ O ₅ + 0 to 9% of Gd ₂ O ₃ , and a refractive index nd of 1.55 to 2.3. SiO ₂ 35~60% in mass% as a glass _{composition, 0~1.5% Li 2 O + Na} 2 O + K 2 O, SrO 0.1~20%, BaO 17~35%, TiO 2 0.01~20%, La 2 O ₃ + Nb ₂ O ₅ + 0 to 9% of Gd ₂ O ₃ , and a refractive index nd of 1.55 to 2.3. 17. The method according to claim 15 or 16,
Further, the content of B ₂ O ₃ is 0 to 3% by mass. 18. The method according to any one of claims 15 to 17,
Further, the content of MgO is 0 to 3% by mass. 19. The method according to any one of claims 15 to 18,
Further, the content of ZrO ₂ + TiO ₂ is 1 to 20% by mass. 20. The method according to any one of claims 15 to 19,
Refractive index glass. 21. The method according to any one of claims 15 to 20,
And a liquid viscosity of 10 ^3.0 dPa s or more. 22. The method according to any one of claims 15 to 21,
Wherein the high refractive index glass is formed by a float method or a down-draw method. SiO ₂ 30~60% in mass% as a glass _{composition, B 2 O 3 0~15%,} Al 2 O 3 0~15%, Li 2 O 0~10%, Na 2 O 0~10%, K 2 O 0-10%, MgO + CaO + SrO + BaO + ZnO, 20-60%, TiO ₂ 0.0001-20%, ZrO ₂ 0-20%, La ₂ O ₃ + Nb ₂ O ₅ 0-10%, The refractive index nd is 1.55-2.3, The high refractive index glass characterized by the above-mentioned. As glass composition, in mass%, SiO ₂ 35-60%, B ₂ O ₃ 0-15%, Al ₂ O ₃ 0-15%, Li ₂ O 0-10%, Na ₂ O 0-10%, K ₂ O 0-10%, MgO + CaO + SrO + BaO + ZnO 20-60%, TiO ₂ 0.0001-20%, ZrO ₂ 0.0001-20%, La ₂ O ₃ + Nb ₂ O ₅ 0-10%, The refractive index nd is 1.55-2.3, The high refractive index glass characterized by the above-mentioned. 35 to 60% of SiO ₂ , 0 to 15% of B ₂ O _3, 0 to 15% of Al ₂ O _3, 0 to 1% of Li ₂ O, 0 to 1% of Na ₂ O, K ₂ O _{0~1%, Li 2 O + Na} 2 O + K 2 O 0~1%, MgO + CaO + SrO + BaO + ZnO 20~50%, BaO 0.1~35%, TiO 2 0.0001~20%, ZrO 2 0.0001 to 20%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 10%, and a refractive index nd of 1.55 to 2.3. 35 to 60% of SiO ₂ , 0 to 15% of B ₂ O _3, 0 to 15% of Al ₂ O _3, 0 to 1% of Li ₂ O, 0 to 1% of Na ₂ O, K ₂ O _{0~1%, Li 2 O + Na} 2 O + K 2 O 0~1%, MgO + CaO + SrO + BaO + ZnO 20~50%, BaO 0.1~35%, TiO 2 0.0001~20%, ZrO 2 0.0001 to 20%, La ₂ O ₃ 0 to 2.5%, La ₂ O ₃ + Nb ₂ O ₅ 0 to 8%, and a refractive index nd of 1.55 to 2.3. 27. The method according to any one of claims 23 to 26,
B ₂ O ₃ in an amount of 1% by mass or more. 28. The method according to any one of claims 23 to 27,
A high refractive index glass characterized by containing 1% by mass or more of MgO. 29. The method according to any one of claims 23 to 28,
Refractive index glass. The method according to any one of claims 23 to 29,
And a liquid viscosity of 10 ^3.0 dPa s or more. The method according to any one of claims 23 to 30,
Wherein the high refractive index glass is formed by a float method or a down-draw method. 32. The method according to any one of claims 23 to 31,
Wherein at least one surface has a surface that is not polished and the surface has a surface roughness Ra of 10 angstroms or less.