TW201529514A - Glass - Google Patents

Abstract

The present invention provides glass suitable as an organic EL lighting substrate and having a high refractive index (nd) while also having the viscosity necessary to make thin-plate molding possible. This glass contains, in mass% calculated by oxide content, an SiO2 component in the amount of 5-50%, an La2O3 component in the amount of 4-35%, a TiO2 component in the amount of 3-30%, a ZrO2 component in the amount of 0-20%, and a BaO component in the amount of 5-50%, wherein the mass ratio ((La2O3+BaO)/SiO2) of the total content of the La2O3 and BaO components to the SiO2 component content is 1.1-4.0, inclusive.

Description

glass

The present invention relates to a glass, and more particularly to an optical glass and a glass having a high refractive index suitable for a glass substrate for organic EL illumination.

The organic EL element is characterized in that it is lightweight and thin, can be driven with low power consumption, and emits light on the surface, and is therefore expected to be used as next-generation illumination. In the organic EL device, an organic light-emitting layer is provided on the surface of the light-transmissive glass substrate via a transparent electrode layer, and a counter electrode is further provided on the surface of the organic light-emitting layer. The organic light-emitting layer emits light by applying a voltage between the transparent electrode layer and the counter electrode. The light emitted from the organic light-emitting layer is transmitted to the outside through the transparent electrode layer and the light-transmitting substrate. Here, since the refractive index of the organic light-emitting layer or the transparent electrode layer is relatively high, if the glass having a higher refractive index is not used for the light-transmitting glass substrate, the interface between the organic light-emitting layer or the transparent electrode layer and the glass substrate is used. Total reflection occurs, and there is a problem that the light extraction efficiency is lowered.

Further, in order to produce the glass substrate for organic EL illumination, it is required to directly form the molten glass into a thin plate shape in order to produce it at low cost.

However, in the prior glass, there is no glass having a higher refractive index which can be formed into a thin plate shape and has a problem of solving total reflection.

Further, in the optical applications other than the glass substrate for organic EL illumination, for example, in the field of wafer-level optical technology, it is also desired to form an optical glass having a high refractive index into a thin plate shape at low cost.

Patent Document 1 discloses a glass having a refractive index nd of 1.74, but an organic light-emitting layer or a transparent layer The refractive index nd of the bright electrode is about 1.9, and a sufficiently high refractive index is not achieved.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent Laid-Open Publication No. 2013-149406

The present invention has been made in view of the above problems, and an object thereof is to obtain a glass having a viscosity which can be formed into a thin plate and having a high refractive index nd.

In order to solve the above problems, the inventors of the present invention have conducted intensive studies, and as a result, have found that a glass having a viscosity suitable for sheet forming and a high refractive index can be obtained by having a specific composition, and the present invention has been completed. Specifically, the present invention provides the following.

(Composition 1)

A glass containing 5% to 50% of SiO ₂ component, 4% to 35% of La ₂ O ₃ component, 3% to 30% of TiO ₂ component, and 0% to 20% of ZrO ₂ component in terms of mass% of oxide. %, BaO component is 5% to 50%, and the mass ratio of the total content of La ₂ O ₃ component and BaO component to the content of SiO ₂ component (La ₂ O ₃ +BaO)/SiO ₂ is 1.1 or more and 4.0. the following.

(constituent 2)

The glass of the composition 1 has a refractive index nd of 1.75 or more.

(constitution 3)

The glass of the composition 1 or 2 contains 0% to 40% of the Y ₂ O ₃ component and 0% to 20% of the Nb ₂ O ₅ component in terms of the mass % of the oxide.

(construction 4)

The glass of any one of 1 to 3, wherein the content of the B ₂ O ₃ component is 0% to 15% by mass% in terms of oxide, and the total content of the SiO ₂ component and the B ₂ O ₃ component is relatively The mass ratio (SiO ₂ + B ₂ O ₃ ) / SiO ₂ of the content of the SiO ₂ component is 1.0 or more and 2.00 or less.

(Constituent 5)

The glass of any one of the items 1 to 4, wherein the mass ratio of the content of the Nb ₂ O ₅ component to the content of the SiO ₂ component relative to the content of the SiO ₂ component is 0.60 in terms of the mass % of the oxide, the value of Nb ₂ O ₅ /SiO ₂ is 0.60. the following.

(constituent 6)

The glass according to any one of 1 to 5, wherein the Gd ₂ O ₃ component is 0% to 40%, the Al ₂ O ₃ component is 0% to 15%, and the MgO component is 0% by mass% by mass. 15%, CaO composition 0% to 15%, and SrO composition 0% to 15%.

(constituent 7)

The glass of any one of 1 to 6, wherein the content of the Ta ₂ O ₅ component is 0% to 10%, and the content of the TeO ₂ component is 0% to 10% by mass% of the oxide, WO ₃ The content of the component is 0% to 10%, the content of the Bi ₂ O ₃ component is 0% to 10%, the content of the Sb ₂ O ₃ component is 0% to less than 0.5%, and the content of the As ₂ O ₃ component is 0%. ~ less than 0.5%, and the content of the Yb ₂ O ₃ component is 0% to 5%, and the content of the Rn ₂ O component (Rn is selected from one or more of Li, Na, and K) is 0% to less than 4 The range of %.

(Composition 8)

The glass of any one of 1 to 7, which has a viscosity at a liquidus temperature of 10.0 dPa ‧ s or more.

(constituent 9)

The glass of any one of 1 to 8, which has a glass transition point Tg of 625 ° C or more.

(construction 10)

The glass of any one of 1 to 9, which has a liquidus temperature of 1300 ° C or less.

(Structure 11)

A glass substrate comprising the glass of any one of 1 to 10.

(construction 12)

An optical element which uses the glass of any one of 1 to 10 as a base material.

According to the present invention, a glass having a viscosity suitable for sheet forming and a high refractive index can be obtained. That is, a glass having a viscosity at a liquidus temperature of 10.0 dPa ‧ s or more and having a refractive index nd of 1.75 or more can be obtained.

Fig. 1 is a graph showing the relationship between the temperature and the viscosity of the glass of Example 1, the horizontal axis is the temperature of the glass melt (°C), and the vertical axis is the common logarithm of the viscosity η (dPa‧s) of the glass (log η) The value of ).

Hereinafter, embodiments of the glass of the present invention will be described in detail. The present invention is not limited to the following embodiments, and can be appropriately modified and implemented within the scope of the object of the present invention. Incidentally, the description of the overlapping portions may be omitted as appropriate, but the present invention is not limited thereto.

[Glass composition]

Hereinafter, the composition range of each component constituting the glass of the present invention will be described. In the case where it is not specifically described in the present specification, the content of each component is expressed by mass% based on the total mass of the glass in terms of oxide composition. Here, the term "oxide-converting composition" refers to a case where an oxide, a composite salt, a metal fluoride or the like which is used as a raw material of the glass constituent component of the present invention is all decomposed and changed into an oxide when it is melted. The total mass of the produced oxide was set to 100% by mass, and the composition of each component contained in the glass was described.

The SiO ₂ component is an essential component that is indispensable for forming an oxide of glass. By containing 5% or more of the SiO ₂ component, the viscosity of the molten glass is improved, and the effect of coloring of the glass is reduced. Therefore, the lower limit of the content of the SiO ₂ component is preferably 5%, more preferably 6.7%, still more preferably 10%, most preferably 13%.

On the other hand, by setting the content of the SiO ₂ component to 50% or less, the decrease in the refractive index can be suppressed, and the devitrification resistance can be improved. Therefore, the upper limit of the content of the SiO ₂ component is preferably 50%, more preferably 45%, still more preferably 40%, most preferably 35%.

The La ₂ O ₃ component is an essential component for increasing the refractive index of the glass. In particular, by containing 4% or more of the La ₂ O ₃ component, it is possible to obtain a desired viscosity suitable for sheet forming without deteriorating the transmittance in the visible light region, and to obtain a desired high refractive index. Therefore, the lower limit of the content of the La ₂ O ₃ component is preferably 4%, more preferably 4.5%, still more preferably 5%, most preferably 6%.

On the other hand, by setting the content of the La ₂ O ₃ component to 35% or less, the desired viscosity suitable for sheet forming can be obtained, and the devitrification resistance of the glass can be improved. Therefore, the upper limit of the content of the La ₂ O ₃ component is preferably 35%, more preferably 32%, still more preferably 30%, most preferably 28%.

The TiO ₂ component obtains a desired viscosity suitable for sheet forming, increases the refractive index of the glass, adjusts the Abbe number to be low, and improves the essential component for devitrification resistance. Therefore, the lower limit of the content of the TiO ₂ component is preferably 3%, more preferably 5%, still more preferably 7%, most preferably 8%.

On the other hand, by setting the content of TiO ₂ to 30% or less, the desired viscosity suitable for sheet forming can be obtained, and the coloring of the glass can be reduced to increase the visible light transmittance, and the excessive TiO ₂ component can be suppressed. The resulting devitrification. Therefore, the upper limit of the content of the TiO ₂ component is preferably 30%, more preferably 28%, still more preferably 25%, and most preferably 22%.

When the content of the ZrO ₂ component is more than 0%, the glass can be made to have a high refractive index and a low dispersion without deteriorating the transmittance in the visible light region, and the devitrification resistance of the glass can be improved. Any ingredient. Therefore, when the ZrO ₂ component is contained, the lower limit of the content is more preferably 1%, still more preferably 2.5%, most preferably 5.1%.

On the other hand, by setting the ZrO ₂ component to 20% or less, it is possible to suppress a decrease in the devitrification resistance of the glass due to the excessive ZrO ₂ component. Therefore, the upper limit of the content of the ZrO ₂ component is preferably 20%, more preferably 15%, still more preferably 9.8%, still more preferably 8.5%, most preferably 7.5%.

The BaO component obtains an essential component suitable for sheet forming, and can improve the meltability of the glass raw material or the devitrification resistance of the glass. Therefore, the lower limit of the content of the BaO component is preferably 5%, more preferably 7%, still more preferably 10.9%, most preferably 15%.

On the other hand, by setting the content of the BaO component to 50% or less, it is possible to suppress a decrease in the refractive index or a decrease in the devitrification resistance due to the excessive inclusion of the components. Therefore, the upper limit of the content of the BaO component is preferably 50%, more preferably 45%, still more preferably 40%, and most preferably 38%.

The glass of the present invention is characterized in that the ratio of the total content of the La ₂ O ₃ component and the BaO component to the content of the SiO ₂ component (La ₂ O ₃ +BaO)/SiO ₂ is 1.1 or more and 4.0 or less. By setting the ratio to 1.1 or more and 4.0 or less, it is possible to obtain a desired viscosity suitable for sheet forming, and it is possible to suppress deterioration of refractive index and deterioration of devitrification resistance. Therefore, the lower limit of the value of the above (La ₂ O ₃ +BaO)/SiO ₂ is preferably 1.1, more preferably 1.2, and most preferably 1.3. Further, the upper limit of the value of the above (La ₂ O ₃ +BaO)/SiO ₂ is preferably 4.0, more preferably 3.8, and most preferably 3.5.

When the Y ₂ O ₃ component contains more than 0%, it is an element having a high refractive index and a specific gravity lowering.

On the other hand, by setting the content of the Y ₂ O ₃ component to 40% or less, the decrease in the refractive index of the glass can be suppressed, and the devitrification resistance of the glass can be improved. Therefore, the upper limit of the content of the Y ₂ O ₃ component is preferably 40%, more preferably 30%, still more preferably 15%, most preferably 10%.

When the Nb ₂ O ₅ component contains more than 0%, the refractive index of the glass can be increased, and any component which is resistant to devitrification can be improved. Therefore, the lower limit of the content of the Nb ₂ O ₅ component may be preferably more than 0%, more preferably 1%, still more preferably 1.7%.

On the other hand, by setting the content of the Nb ₂ O ₅ component to 20% or less, the cost of the material can be suppressed, and the deterioration of the devitrification resistance of the glass due to the excessive Nb ₂ O ₅ component can be suppressed. Or a decrease in the transmittance of visible light. Therefore, the upper limit of the content of the Nb ₂ O ₅ component is preferably 20%, more preferably 14%, most preferably 9.8%.

When the B ₂ O ₃ component contains more than 0%, it can be used as an optional component which forms an oxide of glass.

By containing a B ₂ O ₃ component, the devitrification resistance of the glass can be improved. Therefore, in the case of containing a B ₂ O ₃ component, the lower limit of the content may be more preferably 0.1%, still more preferably 2.5%, most preferably 5.0%.

On the other hand, by setting the content of the B ₂ O ₃ component to 15% or less, a larger refractive index can be easily obtained, and deterioration in chemical durability can be suppressed. Therefore, the upper limit of the content of the B ₂ O ₃ component is preferably 15%, more preferably 10%, still more preferably 7.9%, most preferably 8%.

The glass of the present invention preferably has a mass ratio (SiO ₂ + B ₂ O ₃ ) / SiO ₂ of a total content of the SiO ₂ component and the B ₂ O ₃ component to the content of the SiO ₂ component of 1.0 or more and 2.00 or less. By setting the ratio to 1.0 or more and 2.00 or less, the desired viscosity suitable for sheet metal forming can be obtained, and an effect of excellent durability can be obtained. Therefore, the lower limit of the value of the above (SiO ₂ + B ₂ O ₃ ) / SiO ₂ is preferably 1.0, more preferably 1.1, and most preferably 1.2. Further, the upper limit of the value of the above (SiO ₂ + B ₂ O ₃ ) / SiO ₂ is preferably 2.00, more preferably 1.90, most preferably 1.80.

The glass of the present invention preferably has a sum of the content of the SiO ₂ component and the B ₂ O ₃ component of 19% or more. By setting the sum of the contents of the SiO ₂ component and the B ₂ O ₃ component to 19% or more, the desired viscosity suitable for sheet forming can be obtained, and the deterioration of the devitrification resistance can be suppressed. Therefore, the sum of the contents of the SiO ₂ component and the B ₂ O ₃ component is preferably 19% or more, more preferably 20% or more, and most preferably 21% or more. Further, the sum of the contents of the SiO ₂ component and the B ₂ O ₃ component is preferably 50% or less, more preferably 45% or less, still more preferably 40% or less, and most preferably 33% or less.

The glass of the present invention preferably has a mass ratio Nb ₂ O ₅ /SiO ₂ of a content of the Nb ₂ O ₅ component to the content of the SiO ₂ component of 0.60 or less. By setting the ratio to 0.60 or less, the desired viscosity suitable for sheet metal forming can be obtained, the material cost can be suppressed, and the effect of excellent devitrification resistance can be obtained. Therefore, the upper limit of the value of the above Nb ₂ O ₅ /SiO ₂ is preferably 0.60, more preferably 0.56, still more preferably 0.53, most preferably 0.50. Further, the lower limit of the value of the above Nb ₂ O ₅ /SiO ₂ may be set to zero.

When the Gd ₂ O ₃ component contains more than 0%, it can increase any component of the refractive index of the glass.

On the other hand, by lowering the expensive Gd ₂ O ₃ component, which is also expensive among rare earth elements, to 40.0% or less, the material cost of the glass can be lowered. Further, it is possible to suppress an increase in the Abbe number of the glass or more. Therefore, the upper limit of the content of the Gd ₂ O ₃ component is preferably 40.0%, more preferably 30.0%, still more preferably 10%, still more preferably 5%, most preferably 3%.

When the Al ₂ O ₃ component and the Ga ₂ O ₃ component are contained in an amount exceeding 0%, the chemical durability of the glass can be improved, and any component which is resistant to devitrification of the glass can be improved.

On the other hand, by setting the respective contents of the Al ₂ O ₃ component and the Ga ₂ O ₃ component to 15% or less, it is possible to suppress a decrease in the devitrification resistance of the glass due to the excessive content of the components. Therefore, the upper limit of the respective contents of the Al ₂ O ₃ component and the Ga ₂ O ₃ component is preferably 15%, more preferably 5.0%, and most preferably 3.0%.

When the MgO component is contained in an amount of more than 0%, the composition of the glass raw material can be improved in meltability or resistance to devitrification of the glass.

On the other hand, by setting the content of the MgO component to 15% or less, it is possible to suppress a decrease in the refractive index or a decrease in the devitrification resistance due to the excessive content of the components. Therefore, the upper limit of the content of the MgO component is preferably 15%, more preferably 12%, still more preferably 10%, most preferably 5%.

When the CaO component is contained in an amount exceeding 0%, the composition of the glass raw material can be improved in meltability or devitrification resistance of the glass. However, by setting the content of the CaO component to 15% or less, it is possible to suppress a decrease in refractive index or a decrease in devitrification resistance caused by the excessive inclusion of such components. Therefore, the upper limit of the content of CaO is preferably 15%, more preferably 12%, most preferably 10.3%.

When the SrO component is contained in an amount exceeding 0%, the composition of the glass raw material can be improved in meltability or resistance to devitrification of the glass.

On the other hand, by setting the content of the SrO component to 15% or less, it is possible to suppress a decrease in the refractive index or a decrease in the devitrification resistance due to the excessive content of the components. Therefore, the upper limit of the content of the SrO component is preferably 15%, more preferably 12%, and most preferably 10%.

The total content (mass sum) of the content of the RO component (wherein R is selected from one or more of the group consisting of Mg, Ca, Sr, and Ba) is preferably 50% or less. Thereby, it is possible to suppress a decrease in the refractive index of the glass or a decrease in the devitrification resistance caused by the excessive RO component. Therefore, the upper limit of the sum of the masses of the RO components is preferably 50%, more preferably 45%, and most preferably 40%.

On the other hand, the lower limit of the sum of the masses of the RO components may be preferably more than 0%, more preferably from the viewpoint of improving the meltability of the glass raw material or the resistance to devitrification of the glass. 5%, more preferably 7%, still more preferably 10.9%, still more preferably 15%, still more preferably 20%.

When the Ta ₂ O ₅ component contains more than 0%, the refractive index of the glass can be increased, the devitrification resistance can be improved, and any component which can improve the viscosity of the molten glass can be obtained. On the other hand, by setting the expensive Ta ₂ O ₅ component to 10% or less, the material cost of the glass can be reduced. Therefore, the upper limit of the content of the Ta ₂ O ₅ component is preferably 10%, more preferably 7%, most preferably 5%.

When the TeO ₂ component contains more than 0%, the refractive index can be increased, and any component of the glass transition point can be lowered.

However, TeO ₂ has a problem in that it is alloyed with platinum when it is melted in a molten bath formed of platinum in a crucible made of platinum or in a molten bath formed of platinum. Therefore, the upper limit of the content of the TeO ₂ component is preferably 10%, more preferably 5%, most preferably 3%, and further preferably is not contained.

When the WO ₃ component is contained in an amount of more than 0%, it is possible to reduce the coloration of the glass caused by other high refractive index components and to increase the refractive index, and to improve the devitrification resistance of the glass. Therefore, the lower limit of the content of the WO ₃ component may be more preferably more than 0%, still more preferably 1.0%.

On the other hand, by setting the content of the WO ₃ component to 10% or less, the coloring of the glass due to the WO ₃ component can be reduced, and the visible light transmittance can be improved. Therefore, the upper limit of the content of the WO ₃ component is preferably 10%, more preferably 5%, most preferably 3%.

When the Bi ₂ O ₃ component contains more than 0%, the refractive index can be increased, and any component of the glass transition point can be lowered.

On the other hand, by setting the content of the Bi ₂ O ₃ component to 10.0% or less, the devitrification resistance of the glass can be improved, and the coloring of the glass can be reduced, and the visible light transmittance can be improved. Therefore, the upper limit of the content of the Bi ₂ O ₃ component is preferably 10%, more preferably 5%, most preferably 3%.

When the Yb ₂ O ₃ component contains more than 0%, the refractive index of the glass can be increased, and any component of the Abbe number can be increased.

On the other hand, when the Yb ₂ O ₃ component is excessively added, the devitrification resistance of the glass is easily impaired. Therefore, the upper limit of the content of the Yb ₂ O ₃ component is preferably 5%, more preferably 2%, still more preferably 0.9%, still more preferably 0.5%, and most preferably no Yb ₂ O ₃ component. .

The Rn ₂ O component (wherein Rn is one or more selected from the group consisting of Li, Na, K, and Cs) may be arbitrarily added. However, if it is added excessively, the viscosity of the glass becomes low, and it becomes difficult to obtain a desired viscosity, and it becomes difficult to obtain a high refractive index. Therefore, the content of the Rn ₂ O component is preferably less than 4%, preferably 2% or less, and most preferably is not contained.

When the Li ₂ O component contains more than 0%, the meltability of the glass is improved, and any component of the glass transition point can be lowered. However, when it is added excessively, the viscosity of the glass becomes low, and it becomes difficult to obtain a desired viscosity, and it becomes difficult to obtain a high refractive index. Therefore, it is preferable to set the content to 2% or less. Better not to contain.

When the Na ₂ O component, the K ₂ O component, and the Cs ₂ O component are contained in an amount of more than 0%, the meltability of the glass is improved, the devitrification resistance of the glass is improved, and any component of the glass transition point can be lowered. When it is added excessively, the viscosity of the glass becomes low, and it becomes difficult to obtain a desired viscosity, and it becomes difficult to obtain a high refractive index. Therefore, it is preferable to use a Na ₂ O component and a K ₂ O component. The content of each of the Cs ₂ O components is 2% or less, and more preferably, each component of Na ₂ O, K ₂ O, and Cs ₂ O is not contained.

The ZnO component is an optional component which increases the refractive index and improves chemical durability when it contains more than 0%. Therefore, the content of the ZnO component may preferably be more than 0%, more preferably more than 1.0%.

On the other hand, by setting the content of the ZnO component to 10% or less, it is possible to suppress a decrease in the refractive index of the glass or a decrease in viscosity, and it is possible to reduce the occurrence of streaks on the glass. Therefore, the upper limit of the content of the ZnO component is preferably 10%, more preferably 8%, most preferably 6%.

When the P ₂ O ₅ component is contained in an amount exceeding 0%, the component which is resistant to devitrification of the glass can be improved. In particular, by setting the content of the P ₂ O ₅ component to 10.0% or less, the chemical durability of the glass, particularly the water resistance, can be suppressed. Therefore, the upper limit of the content of the P ₂ O ₅ component is preferably 10.0%, more preferably 5.0%, still more preferably 3.0%.

When the GeO ₂ component contains more than 0%, the refractive index of the glass can be increased, and any component which is resistant to devitrification can be improved. However, since the price of the GeO ₂ raw material is high, if the amount is large, the material cost becomes high. Therefore, the upper limit of the content of the GeO ₂ component is preferably 10.0%, more preferably 8.0%, still more preferably 5.0%, still more preferably 3.0%.

When the content of the SnO ₂ component is more than 0%, the oxidation of the molten glass can be alleviated and clarified, and any component of the visible light transmittance of the glass can be improved.

On the other hand, by setting the content of the SnO ₂ component to 1.0% or less, it is possible to reduce the coloration of the glass caused by the reduction of the molten glass or the devitrification of the glass. Further, since the alloying of the SnO ₂ component and the melting device (especially a noble metal such as Pt) can be alleviated, the longevity of the melting device can be achieved. Therefore, the upper limit of the content of the SnO ₂ component is preferably 1.0%, more preferably 0.7%, still more preferably 0.5%.

The Sb ₂ O ₃ component is an optional component which can defoam the molten glass when it contains more than 0%.

On the other hand, when the amount of Sb ₂ O ₃ is too large, the transmittance in the short-wavelength region in the visible light region is deteriorated. Therefore, the upper limit of the content of the Sb ₂ O ₃ component is preferably less than 0.5%, more preferably 0.4%.

Since the As ₂ O ₃ component is a component having a high environmental load, it is preferable to set the content to less than 0.5%, and more preferably it is not contained.

Further, the component for clarifying and defoaming the glass is not limited to the above Sb ₂ O ₃ component, and a known clarifying agent, an antifoaming agent or a combination thereof may be used in the field of glass production.

<About ingredients that should not be included>

Secondly, the optical glass of the present invention should not contain components and should not be contained. The points are explained.

Other components not described above may be added as needed within the scope of the characteristics of the glass of the invention of the present invention. In addition to Ti, Zr, Nb, W, La, Gd, Y, Yb, and Lu, each of the transition metal components such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo is contained in a small amount or When it is combined and contained in a small amount, the glass is colored to absorb the specific wavelength of the visible light region, and therefore it is preferably substantially not contained.

Further, since a lead compound such as PbO is a component having a high environmental load, it is preferably substantially not contained, that is, it is not contained at all except inevitably.

Further, in recent years, various components of Th, Cd, Tl, Os, Be, and Se have been favorably used as harmful chemical materials, and environmental measures are required not only for the manufacturing steps of the glass but also for the processing steps and after the product is processed. The measures on it. Therefore, when it is important to pay attention to the influence of the environment, it is preferable that it does not substantially contain such.

[Production method]

The glass of the present invention is produced, for example, by the following method. That is, the raw materials are uniformly mixed so that the respective components are within a specific content, and the produced mixture is put into platinum crucible, and melted in a temperature range of 1100 to 1500 ° C in an electric furnace according to the melting difficulty of the glass composition. After ~5 hours, the mixture was homogenized, lowered to a suitable temperature, cast into a mold and slowly cooled, thereby being produced.

[physical property]

The glass of the present invention preferably has a high refractive index. In particular, the lower limit of the refractive index (n _d ) of the glass of the present invention is preferably 1.75, more preferably 1.76, most preferably 1.77. The upper limit of the refractive index may be preferably 1.91, more preferably 1.90, still more preferably 1.89. When the glass substrate for an organic EL is produced using the glass of the present invention by having such a high refractive index, total reflection is suppressed at the interface between the organic light-emitting layer or the transparent electrode layer and the glass substrate, and the light extraction efficiency can be improved. Moreover, even when the glass of the present invention is used for an optical element such as a lens, even if the optical element is made thinner, a large amount of refraction of light can be obtained.

The glass of the present invention preferably has a high dispersion (low Abbe number). In particular, the upper limit of the Abbe number (ν _d ) of the glass of the present invention is preferably 45, more preferably 42, more preferably 40, most preferably 38. The lower limit of the Abbe number may also be set to preferably 20, more preferably 22, and still more preferably 25.

The glass of the present invention preferably has a higher resistance to devitrification and, more specifically, a lower liquidus temperature. That is, the upper limit of the liquidus temperature of the glass of the present invention is preferably 1300 ° C, more preferably 1250 ° C, still more preferably 1200 ° C. Thereby, even if the molten glass flows out at a lower temperature, the crystallization of the produced glass can be reduced, so that the devitrification of the glass when the glass is formed from the molten state can be reduced, and the substrate or the optical element for using the glass can be lightened. The effect of optical properties. Moreover, since the glass can be formed even if the melting temperature of the glass is made low, the manufacturing cost can be reduced by suppressing the energy consumed during the glass molding. On the other hand, the lower limit of the liquidus temperature of the glass of the present invention is not particularly limited, and the lower limit of the liquidus temperature of the glass obtained by the present invention may be preferably 500 ° C, more preferably 600 ° C, and further It is preferably 700 °C.

In addition, the "liquidus temperature" in the present specification means that a 30 cc glass-like glass sample is placed in a platinum crucible having a capacity of 50 ml, and is completely melted at 1,350 ° C, and is cooled to a specific temperature. The temperature was maintained for 12 hours, and after taking out to the outside of the furnace and cooling, immediately observe the presence or absence of crystals on the surface of the glass and the glass, and the lowest temperature of crystallization was not observed. Here, the specific temperature at the time of temperature lowering is a temperature at intervals of 10 ° C up to 500 ° C.

The glass of the present invention has a viscosity of a glass melt at a liquidus temperature of 10.0 dPa ‧ s or more. By having such a viscosity, generation of streaks can be suppressed, and the molten glass can be formed into a thin plate. Therefore, the viscosity of the glass melt at the liquidus temperature of the glass of the present invention is preferably 10.0 dPa ‧ or more, more preferably 31.6 dPa ‧ s or more, and most preferably 100.0 dPa ‧ s or more . Further, the upper limit of the viscosity of the glass melt at the liquidus temperature is not particularly set, and the upper limit of the range of the viscosity of the glass of the present invention is 10 ^4.5 dPa‧s.

Further, the viscosity of the glass melt at the liquidus temperature can be measured in advance by measuring the liquidus temperature of the glass of the object, and the glass is kept at this temperature and measured by a pull ball type viscometer (manufactured by OPT Co., Ltd.).

The glass of the present invention preferably has a high transmittance of visible light transmittance, particularly light on the short-wavelength side in visible light, and therefore has less coloration.

When the glass of the present invention is expressed by the transmittance of glass, the upper limit of the wavelength (λ ₇₀ ) at which the spectral transmittance of 70% is displayed as a sample having a thickness of 10 mm is preferably 600 nm, more preferably 550 nm, and still more preferably 500 nm, and more preferably 470 nm.

Further, the sample having a thickness of 10 mm of the optical glass of the present invention exhibits an upper limit of the shortest wavelength (λ ₅ ) of 5% of the spectral transmittance, preferably 470 nm, more preferably 460 nm, still more preferably 400 nm.

As a result, the absorption end of the glass is in the vicinity of the ultraviolet ray region, and the transparency to the visible light is improved. Therefore, the glass can be preferably used as an optical element for transmitting light such as a substrate or a lens for organic EL illumination.

The glass of the present invention preferably has a glass transition point (Tg) of 625 ° C or higher. Thereby, the molten glass can be easily formed into a thin plate shape. Therefore, the lower limit of the glass transition point of the optical glass of the present invention is preferably 625 ° C, more preferably 650 ° C, still more preferably 700 ° C, still more preferably 710 ° C. Furthermore, the upper limit of the glass transition point of the present invention may also be set to preferably 800 °C.

[Formation of thin plate shape]

Since the glass of the present invention has a liquidus temperature and viscosity suitable for forming molten glass into a thin plate shape, the molten glass can be directly formed into a thin plate shape by a known method. Examples of the method of forming the glass of the present invention into a thin plate shape include a floating method, a down-draw method, a melting method, an aqua-float method, and the like. Since the glass of the present invention can directly form the molten glass into a thin plate shape, the substrate for organic EL illumination can be manufactured at low cost His thin sheet for optical use.

Further, since the glass of the present invention has high viscosity at a liquidus temperature, it can be formed into a thin plate shape by a direct press method. The direct pressurization method is a method in which molten glass is directly press-formed in at least two opposing molds. In the manufacture of the glass of the present invention, the direct press method can be suitably used, for example, for producing a molded article of a wafer-level optical optical element group or for forming a wafer-level optical optical element by reheat pressing. The case of the glass substrate of the molded article of the group.

[Glass molded body and optical element]

The glass of the present invention can be used to produce a glass molded body by, for example, a grinding and polishing method. That is, the glass can be subjected to mechanical processing such as grinding and polishing to produce a glass molded body. Further, the method of producing the glass molded body is not limited to these methods, and the above direct press method or reheat press method may be used.

Thus, the glass formed body formed by the glass of the present invention is useful for various optical elements and optical designs, and particularly preferably used for optical elements such as lenses or iridium. As a result, a glass molded body having a large diameter can be formed, so that an increase in size of the optical element can be achieved, and high-definition and high-precision imaging characteristics and projection can be realized when used in an optical device such as a camera or a projector. characteristic.

[Examples]

The composition of the glass of the present invention, the refractive index (n _d ), the Abbe number (ν _d ), and the spectral transmittance of the glass are shown as wavelengths of 5% and 70% (λ ₅ and λ ₇₀ ), The results of the liquid phase temperature, the viscosity at the liquidus temperature, and the glass transition point (Tg) are shown in Tables 1 to 27. Furthermore, the following examples are for illustrative purposes and are not limited to the embodiments.

In the glass of the examples of the present invention, oxides, hydroxides, carbonates, nitrates, fluorides, hydroxides, metaphosphoric compounds, etc., which are respectively equivalent to the raw materials of the respective components, are selected for high purity of optical glass. The raw materials were weighed and uniformly mixed in such a manner as to be a ratio of the compositions of the respective examples shown in the table, and then introduced into a platinum crucible. According to the melting difficulty of the glass composition, it is melted in an electric furnace at a temperature of 1100 to 1500 ° C for 2 to 5 hours, and then homogenized, cast into a mold or the like, and slowly cooled to prepare a glass.

Here, the refractive index and Abbe number of the glass of the examples were measured based on the Japan Optical Glass Industry Association standard JOGIS01-2003. Here, the refractive index and the Abbe number were determined by measuring the glass obtained by setting the slow cooling rate to -25 ° C /hr.

Further, the transmittance of the glass of the examples was measured in accordance with the Japan Optical Glass Industry Association standard JOGIS02-2003. Specifically, according to JIS Z8722, a light transmittance of 200 to 800 nm is measured for a parallel surface-polished product having a thickness of 10 ± 0.1 mm, and λ ₅ (wavelength at a transmittance of 5%) and λ ₇₀ (transmittance at 70) are obtained. The wavelength at %).

Further, the liquid phase temperature of the glass of the example was placed in a glass crucible having a capacity of 50 ml, and a 30 cc glass flake-shaped glass sample was placed, and the molten glass was completely melted at 1,350 ° C, and the temperature was lowered to 1300 ° C to 500 ° C. At any temperature set at intervals of 10 ° C in ° C for 12 hours, the mixture was taken out of the furnace and cooled, and immediately, the presence or absence of crystals in the glass surface and the glass was observed, and the lowest temperature at which no crystals were observed was determined.

Further, the viscosity of the glass melt at the liquidus temperature of the glass of the example is that the liquidus temperature of the target glass is measured in advance, the glass is kept at this temperature, and the ball viscometer (manufactured by OPT Co., Ltd.) is used. Determination.

Further, the glass transition point (Tg) of the glass of the example was determined by measurement using a transverse expansion tester. Here, the sample used for the measurement is used. For 4.8 mm and length 50 to 55 mm, the heating rate is set to 4 ° C / min.

From this, it is clear that the glass of the examples of the present invention has a refractive index nd of 1.75 or more, and the viscosity of the glass melt at the liquidus temperature is 10.0 dPa·s or more, and the molten glass can be easily formed into a thin plate shape. Further, the liquid phase temperature of the glass of the embodiment of the present invention is 1300 ° C or lower, which is within the desired range. Therefore, it is clear that the optical glass of the embodiment of the present invention has a low liquidus temperature and a high resistance to devitrification.

The glass of the present invention is suitable for use in organic EL illumination substrates, and is also suitable for use in lenses and other optical components.

Claims (12)

A glass containing 5% to 50% of SiO ₂ component, 4% to 35% of La ₂ O ₃ component, 3% to 30% of TiO ₂ component, and 0% of ZrO ₂ component in terms of mass% of oxide. 20%, the BaO component is 5% to 50%, and the mass ratio of the La ₂ O ₃ component and the BaO component to the content of the SiO ₂ component (La ₂ O ₃ +BaO)/SiO ₂ is 1.1 or more. Below 4.0. The glass of claim 1 has a refractive index nd of 1.75 or more. The glass of the claim 1 or 2 contains, in mass% of the oxide, 0% to 40% of the Y ₂ O ₃ component and 0% to 20% of the Nb ₂ O ₅ component. The glass according to any one of claims 1 to 3, wherein the B ₂ O ₃ component is contained in a range of 0% to 15% by mass in terms of oxide, and the total content of the SiO ₂ component and the B ₂ O ₃ component. The mass ratio (SiO ₂ + B ₂ O ₃ ) / SiO ₂ with respect to the content of the SiO ₂ component is 1.0 or more and 2.00 or less. The glass according to any one of claims 1 to 4, wherein the mass ratio of the content of the Nb ₂ O ₅ component to the content of the SiO ₂ component is Nb ₂ O ₅ /SiO _{2 in terms} of mass% of the oxide. Below 0.60. The glass according to any one of claims 1 to 5, which contains, in terms of mass% of oxide, Gd ₂ O ₃ component 0% to 40%, Al ₂ O ₃ component 0% to 15%, and MgO component 0 %~15%, CaO content 0%~15%, and SrO composition 0%~15%. The glass according to any one of claims 1 to 6, wherein the content of the Ta ₂ O ₅ component is 0% to 10%, and the content of the TeO ₂ component is 0% to 10% by mass% of the oxide, WO The content of the _three components is 0% to 10%, the content of the Bi ₂ O ₃ component is 0% to 10%, the content of the Sb ₂ O ₃ component is 0% to less than 0.5%, and the content of the As ₂ O ₃ component is 0. %~ is less than 0.5%, and the content of the Yb ₂ O ₃ component is 0% to 5%, and the content of the Rn ₂ O component (Rn is selected from one or more of Li, Na, and K) is 0% to not Up to 4% range. The glass of any one of claims 1 to 7 has a viscosity at a liquidus temperature of 10.0 dPa ‧ s or more. The glass of any one of claims 1 to 8, which has a glass transition point Tg of 625 ° C or higher. The glass of any one of claims 1 to 9, which has a liquidus temperature of 1300 ° C or less. A glass substrate comprising the glass according to any one of claims 1 to 10. An optical element which uses the glass according to any one of claims 1 to 10 as a base material.