Glass material

Abstract

The present invention provides a glass material that maintains desired optical properties and is less likely to exhibit defects such as crystallization or devitrification products. The glass material of the present invention is characterized in that the refractive index is 1.8 or more, and the content of Al2O3 is more than 0 and 500 ppm or less.

Description

Technical Field

[0001] The present invention relates to a glass material for optical elements such as cameras, microscopes, and endoscopes. Background Art

[0002] In recent years, with the miniaturization and lightening of optical systems used in cameras, microscopes, endoscopes, etc., optical elements such as optical lenses used require optical characteristics of high refractive index and high dispersion. In order to make the glass used for optical elements have a higher refractive index, it is necessary to reduce the content of the main framework components SiO 2 , B 2 O 3 and contain a large amount of rare earth oxides such as La 2 O 3 , Gd 2 O 3 , Ta 2 O 5 or intermediate oxides such as Nb 2 O 5 , TiO 2 . However, if the framework components are reduced and a large amount of intermediate oxides are contained, the glass-forming ability decreases and vitrification becomes difficult. General optical glass is produced by melting raw materials in a melting container such as a crucible and then cooling. In the case of a glass composition with poor glass-forming ability, in the existing production method, crystallization easily occurs starting from the contact interface with the melting container.

[0003] Even for a composition that is difficult to vitrify, by not coming into contact with the melting container and accelerating the cooling rate from the molten state, vitrification can be achieved. As such a method, there is known a containerless floating method (containerless solidification method) in which raw materials are melted and cooled in a floating state. When using this method, the molten glass can hardly come into contact with the melting container and is rapidly cooled, so even a composition that is difficult to vitrify as described above can be vitrified. For example, in Patent Document 1, a glass containing only TiO 2 and BaO as the glass composition was produced by the containerless floating method.

[0004] Prior Art Documents

[0005] Patent Documents

[0006] Patent Document 1: Japanese Patent No. 4789086 Gazette Summary of the Invention

[0007] Technical Problem to be Solved by the Invention

[0008] Even when using the containerless floating method, there are cases where crystallization occurs during the manufacturing process and a glass material cannot be obtained, or cases where devitrification products are formed in the obtained glass. This tendency is particularly significant in the case of compositions that are difficult to vitrify.

[0009] To prevent the occurrence of crystallization or devitrification products, adding network-forming oxides is useful, but generally, network-forming oxides have the effect of reducing the refractive index, and there is a concern that the desired optical properties cannot be obtained.

[0010] In view of the above, an object of the present invention is to provide a glass material that maintains the desired optical properties and is less likely to exhibit defects such as crystallization or devitrification products.

[0011] Technical solution for solving the technical problem

[0012] The glass material of the present invention is characterized in that the refractive index is 1.8 or more, and the content of Al 2 O 3 exceeds 0 and is 500 ppm or less.

[0013] Thus, only a very small amount of Al 2 O 3 exceeding 0 and being 500 ppm or less is contained as an essential component in the glass material, so that the occurrence of crystallization or devitrification products can be suppressed without reducing the refractive index.

[0014] The glass material of the present invention is characterized in that it contains, in mol%, more than 0 and 70% or less of La 2 O 3 , more than 0 and less than 100% of Gd 2 O 3 +Y 2 O 3 +Yb 2 O 3 +Lu 2 O 3 +ZrO 2 +TiO 2 +Nb 2 O 5 +Ta 2 O 5 +WO 3 +Ga 2 O 3 +GeO 2 +B 2 O 3 +SiO 2 +P 2 O 5In the present invention, "○+○+..." represents the total amount of the contents of each component. Here, each component does not necessarily have to be contained as an essential component, and it is also possible that there is a component that is not contained (0%).

[0015] According to the above constitution, a glass material having a refractive index of 1.8 or more can be easily obtained.

[0016] The glass material of the present invention is preferably used as an optical element.

[0017] The glass material of the present invention is preferably used for decorative purposes.

[0018] The method for producing the glass material of the present invention is a method for producing any one of the above glass materials, and is characterized by including: a step of heating and melting a raw material block to obtain molten glass by ejecting a gas from a gas ejection hole that opens on a forming surface of a forming die, floating the raw material block on the forming surface and maintaining it, and then cooling the molten glass.

[0019] Effects of the Invention

[0020] According to the present invention, it is possible to obtain a glass material that maintains desired optical properties and is less likely to exhibit defects such as crystallization or devitrification. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 is a schematic cross-sectional view showing an embodiment of an apparatus for producing the glass material of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0022] The refractive index (nd) of the glass material of the present invention is 1.8 or more, preferably 1.9 or more, and particularly preferably 2.0 or more. Thus, it is suitable for use in optical elements and decorative applications.

[0023] The glass material of the present invention contains Al 2 O 3 as an essential component. Al 2 O 3 is a component that suppresses crystallization of the molten glass during cooling or the formation of devitrification in the glass. The content of Al 2 O 3 is more than 0 and 500 ppm or less, preferably 0.5 to 400 ppm, more preferably 1 to 300 ppm, and particularly preferably 3 to 250 ppm. When the content of Al 2 O 3 is too small, it is difficult to obtain the above effects. On the other hand, when the content of Al 2 O 3 is too large, the refractive index decreases, and it is difficult to obtain the desired optical properties.

[0024] The glass article of the present invention preferably contains more than 0 and 70% or less of La in terms of mol%. 2 O 3 、more than 0 and less than 100% of Gd 2 O 3 +Y 2 O 3 +Yb 2 O 3 +Lu 2 O 3 +ZrO 2 +TiO 2 +Nb 2 O 5 +Ta 2 O 5 +WO 3 +Ga 2 O 3 +GeO 2 +B 2 O 3 +SiO 2 +P 2 O 5 。The reasons for limiting the glass composition in this way will be described below. In the following descriptions of the contents of the respective components, unless otherwise specified, "%" means "mol%".

[0025] La 2 O 3 is a component that forms the glass skeleton and is a component that increases the refractive index without reducing the light transmittance. In addition, it also has the effect of improving the weather resistance. The content of La 2 O 3 is preferably more than 0 and 70% or less, 5 to 68%, and particularly preferably 10 to 63%. When the content of La 2 O 3 is too small, it is difficult to obtain the above effects. On the other hand, when the content of La 2 O 3 is too large, vitrification becomes difficult.

[0026] Gd 2 O 3 、Y 2 O 3 、Yb 2 O 3 、Lu 2 O 3 、ZrO 2 、TiO 2 、Nb 2 O 5 、Ta 2 O 5 、WO 3 、Ga 2O 3 , GeO 2 , B 2 O 3 , SiO 2 and P 2 O 5 are components that increase the refractive index and widen the vitrification range. Gd 2 O 3 + Y 2 O 3 + Yb 2 O 3 + Lu 2 O 3 + ZrO 2 + TiO 2 + Nb 2 O 5 + Ta 2 O 5 + WO 3 + Ga 2 O 3 + GeO 2 + B 2 O 3 + SiO 2 + P 2 O 5 The content is preferably more than 0%, more than 5%, more than 10%, more than 20%, especially more than 30%. Gd 2 O 3 + Y 2 O 3 + Yb 2 O 3 + Lu 2 O 3 + ZrO 2 + TiO 2 + Nb 2 O 5 + Ta 2 O 5 + WO 3 + Ga 2 O 3 + GeO 2 + B 2 O 3 + SiO 2 + P 2 O 5 When the content is too small, it is difficult to obtain the above effects. On the other hand, regarding Gd 2 O 3 + Y 2 O 3 + Yb 2 O 3 + Lu 2 O 3+ZrO 2 +TiO 2 +Nb 2 O 5 +Ta 2 O 5 +WO 3 +Ga 2 O 3 +GeO 2 +B 2 O 3 +SiO 2 +P 2 O 5 The upper limit of the content, considering the content of other components, is preferably less than 100%, 99% or less, especially 95% or less. In addition, the total content of any two or more of the above components is also preferably within the above range.

[0027] Next, for Gd 2 O 3 、Y 2 O 3 、Yb 2 O 3 、Lu 2 O 3 、ZrO 2 、TiO 2 、Nb 2 O 5 、Ta 2 O 5 、WO 3 、Ga 2 O 3 、GeO 2 、B 2 O 3 、SiO 2 and P 2 O 5 each component will be described in detail.

[0028] Gd 2 O 3 is a component that increases the refractive index. In addition, it also has the effect of improving weather resistance. However, when the content of Gd 2 O 3 is too high, vitrification becomes difficult. Therefore, the content of Gd 2 O 3 is preferably 0 to 40%, 1 to 35%, especially 3 to 30%.

[0029] Y 2 O 3 is a component that increases the refractive index. In addition, it also has the effect of improving weather resistance. However, when Y 2 O 3When the content of [substance] is excessive, vitrification becomes difficult. Therefore, Y 2 O 3 The content is preferably 0 to 30%, 1 to 25%, particularly 5 to 20%.

[0030] Yb 2 O 3 is a component that increases the refractive index. However, when the content of Yb 2 O 3 is excessive, vitrification becomes difficult. Also, there is a tendency for the raw material cost to increase. Therefore, the content of Y 2 O 3 is preferably 0 to 30%, 1 to 25%, particularly 5 to 20%.

[0031] Lu 2 O 3 is a component that increases the refractive index. However, when the content of Lu 2 O 3 is excessive, vitrification becomes difficult, and there is a tendency for the raw material cost to increase. Therefore, the content of Lu 2 O 3 is preferably 0 to 20%, 1 to 15%, particularly 5 to 10%.

[0032] ZrO 2 is a component that increases the refractive index. In addition, it forms the glass skeleton as an intermediate oxide, so it has the effect of expanding the vitrification range. However, when the content of ZrO 2 is excessive, vitrification becomes difficult and the melting temperature becomes too high. Therefore, the content of ZrO 2 is preferably 0 to 40%, 1 to 30%, 3 to 25%, particularly 5 to 20%.

[0033] TiO 2 is a component with a relatively large effect of increasing the refractive index, and also has the effect of improving chemical durability. And it has the effect of expanding the vitrification range. The content of TiO 2 is preferably 0 to 90%, 5 to 85%, particularly 10 to 80%. When the content of TiO 2 is excessive, since the absorption edge shifts to the long wavelength side, the transmittance of visible light (especially visible light in the short wavelength region) tends to decrease. In addition, vitrification becomes difficult.

[0034] Nb 2 O 5 is a component with a relatively large effect of increasing the refractive index, and also has the effect of expanding the vitrification range. The content of Nb 2 O 5 is preferably 0 to 80%, 1 to 75%, 5 to 70%, particularly 10 to 65%. Nb 2 O5 When the content is too small, it is difficult to obtain the above effects. On the other hand, when the content of Nb 2 O 5 is too large, vitrification becomes difficult.

[0035] Ta 2 O 5 is a component that has a relatively large effect on increasing the refractive index. However, when the content of Ta 2 O 5 is too large, vitrification becomes difficult, and there is a tendency for the raw material cost to increase. Therefore, the content of Ta 2 O 5 is preferably 0 to 60%, 0.1 to 50%, 3 to 45%, and particularly 5 to 40%.

[0036] WO 3 is a component that increases the refractive index. However, when the content of WO 3 is too large, vitrification becomes difficult. Therefore, the content of WO 3 is preferably 0 to 30%, 1 to 25%, and particularly 5 to 20%.

[0037] Ga 2 O 3 is a component that expands the vitrification range because it forms a glass skeleton as an intermediate oxide. In addition, it has the effect of increasing the refractive index. However, when the content of Ga 2 O 3 is too large, vitrification becomes difficult, and there is a tendency for the raw material cost to increase. Therefore, the content of Ga 2 O 3 is preferably 0 to 60%, 0 to 50%, 0 to 40%, and particularly 0 to 30%.

[0038] GeO 2 is a component that increases the refractive index and also has the effect of expanding the vitrification range. However, when the content of GeO 2 is too large, there is a tendency for the raw material cost to increase. Therefore, the content of GeO 2 is preferably 0 to 10%, more preferably 0 to 5%.

[0039] B 2 O 3 is a component that constitutes the glass skeleton and expands the vitrification range. In addition, it lowers the glass transition temperature and makes press molding easier. However, when the content of B 2 O 3 is too large, the refractive index decreases, and it is difficult to obtain the desired optical properties. Therefore, the content of B 2 O 3 is preferably 0 to 50%, 0.1 to 40%, 3 to 38%, and particularly 5 to 37%.

[0040] SiO 2 is a component that forms the glass skeleton and expands the vitrification range. However, when the content of SiO 2 is too high, the refractive index decreases, and it is difficult to obtain the desired optical properties. Therefore, the content of SiO 2 is preferably 0 to 40%, 0 to 30%, particularly 0.1 to 20%.

[0041] P 2 O 5 is a component that forms the glass skeleton and has the effect of expanding the vitrification range. However, when its content is too high, phase separation becomes easy. Therefore, the content of P 2 O 5 is preferably 0 to 10%, more preferably 0 to 5%.

[0042] In addition, in order to obtain optical properties with a high refractive index, it is preferable to adjust the content of Gd 2 O 3 +Y 2 O 3 +Yb 2 O 3 +Lu 2 O 3 +ZrO 2 +TiO 2 +Nb 2 O 5 +Ta 2 O 5 +WO 3 +Ga 2 O 3 +GeO 2 . The content of Gd 2 O 3 +Y 2 O 3 +Yb 2 O 3 +Lu 2 O 3 +ZrO 2 +TiO 2 +Nb 2 O 5 +Ta 2 O 5 +WO 3 +Ga 2 O 3 +GeO 2 is preferably 0% or more, more than 0%, 5% or more, 10% or more, 20% or more, particularly 30% or more. However, when Gd 2 O 3 +Y 2 O3 +Yb 2 O 3 +Lu 2 O 3 +ZrO 2 +TiO 2 +Nb 2 O 5 +Ta 2 O 5 +WO 3 +Ga 2 O 3 +GeO 2 When the content of [substance] is too high, vitrification becomes difficult. Therefore, it is preferably less than 100%, 99% or less, especially 95%.

[0043] In addition, in order to facilitate vitrification, it is preferable to adjust the content of B 2 O 3 +SiO 2 +P 2 O 5 The content of B 2 O 3 +SiO 2 +P 2 O 5 is preferably 0% or more, more than 0%, 0.1% or more, 3% or more, especially 5% or more. However, when the content of B 2 O 3 +SiO 2 +P 2 O 5 is too high, the refractive index decreases and it is difficult to obtain the desired optical properties. Therefore, it is preferably 80% or less, 75% or less, especially 70% or less.

[0044] The glass article of the present invention can suppress inappropriate crystallization during the production of glass and easily increase the size of the glass article (for example, 2 mm or more, 3 mm or more, 4 mm or more, especially 5 mm or more in diameter) by actively containing components such as La 2 O 3 , Nb 2 O 5 , TiO 2 , B 2 O 3 that expand the vitrification range.

[0045] The glass article of the present invention can contain the following components in addition to the above components.

[0046] MgO, CaO, SrO, BaO, and ZnO are components that expand the vitrification range. These components can each be contained in a range of 10% or less. When the content of these components is excessive, the refractive index decreases, and it becomes difficult to obtain the desired optical properties.

[0047] By containing a coloring component including an oxide of V, Cr, Mn, Fe, Co, Ni, Cu, Mo, Ru, Ce, Pr, or Er, the glass article can be adjusted to the desired hue and can be well used for decorative purposes. These coloring components can be contained individually or two or more of them can be contained. The content of these oxides (the total amount in the case of containing two or more) is preferably 0 to 20%, 0.001 to 10%, 0.005 to 5%, particularly 0.01 to 1%. Additionally, depending on the components contained, the coloring may become too strong and the visible light transmittance is likely to decrease. As a result, sometimes the desired brilliance and fire cannot be obtained, and it is difficult to be used as a decoration. In such a case, the content of the above oxides can also be less than 1%, 0.5% or less, and further 0.1% or less.

[0048] In addition, as a specific example of the composition of the glass article, La 2 O 3 -Nb 2 O 5 system, La 2 O 3 -TiO 2 system, La 2 O 3 -Ta 2 O 5 system, La 2 O 3 -B 2 O 3 system can be cited.

[0049] As for the La 2 O 3 -Nb 2 O 5 system, it can be cited that it contains 5 to 80% (preferably 10 to 70%) of La 2 O 3 , 1 to 80% (preferably 20 to 70%) of Nb 2 O 5 , 0 to 80% (preferably 0 to 75%) of TiO 2 , 0 to 45% (preferably 0 to 40%) of Ta 2 O 5 , 0 to 20% (preferably 0 to 15%) of Gd 2 O 3 , 0 to 25% (preferably 0 to 20%) of ZrO 2, 0 to 30% (preferably 0 to 20%) of WO 3 , 0 to 50% (preferably 0 to 40%) of B 2 O 3 , 0 to 40% (preferably 0 to 35%) of SiO 2 , 0 to 70% (preferably 0 to 60%) of Ga 2 O 3 , 0 to 50% (preferably 0 to 40%) of ZnO.

[0050] As the La 2 O 3 -TiO 2 system, it can be exemplified that it contains 5 to 40% (preferably 10 to 35%) of La 2 O 3 , 40 to 85% (preferably 50 to 80%) of TiO 2 , 0 to 55% (preferably 0 to 50%) of Ta 2 O 5 , 0 to 20% (preferably 1 to 15%) of Gd 2 O 3 , 0 to 25% (preferably 5 to 20%) of ZrO 2 , 0 to 30% (preferably 0 to 20%) of WO 3 , 0 to 50% (preferably 0 to 40%) of B 2 O 3 , 0 to 40% (preferably 0 to 35%) of SiO 2 , 0 to 70% (preferably 0 to 60%) of Ga 2 O 3 , 0 to 50% (preferably 0 to 40%) of ZnO.

[0051] As the La 2 O 3 -Ta 2 O 5 system, it can be exemplified that it contains 10 to 80% (preferably 20 to 70%) of La 2 O 3 , 5 to 70% (preferably 10 to 60%) of Ta 2 O 5 , 0 to 20% (preferably 0 to 15%) of Gd 2 O 3 , 0 to 25% (preferably 0 to 20%) of ZrO 2 , 0 to 30% (preferably 0 to 20%) of WO 3 , 0 to 50% (preferably 0 to 40%) of B 2 O 3 , 0 to 40% (preferably 0 to 35%) of SiO2 , 0 to 70% (preferably 0 to 60%) of Ga 2 O 3 , 0 to 50% (preferably 0 to 40%) of ZnO.

[0052] As for the La 2 O 3 -B 2 O 3 system, examples include those containing 20 to 75% (preferably 30 to 70%) of La 2 O 3 , 5 to 70% (preferably 10 to 60%) of B 2 O 3 , 0 to 20% (preferably 0 to 15%) of Gd 2 O 3 , 0 to 25% (preferably 0 to 20%) of ZrO 2 , 0 to 30% (preferably 0 to 20%) of WO 3 , 0 to 40% (preferably 0 to 35%) of SiO 2 , 0 to 50% (preferably 0 to 40%) of Ga 2 O 3 , 0 to 50% (preferably 0 to 40%) of ZnO.

[0053] As for the La 2 O 3 -Ga 2 O 3 , examples include those containing 10 to 60% (preferably 20 to 55%) of La 2 O 3 , 5 to 75% (preferably 10 to 60%) of Ga 2 O 3 , 0 to 20% (preferably 0 to 15%) of Gd 2 O 3 , 0 to 25% (preferably 0 to 20%) of ZrO 2 , 0 to 30% (preferably 0 to 20%) of WO 3 , 0 to 40% (preferably 0 to 35%) of SiO 2 , 0 to 50% (preferably 0 to 40%) of ZnO.

[0054] The glass material of the present invention can be used for optical elements such as lenses or prisms, or for decorative purposes such as jewelry, artworks, and tableware.

[0055] Figure 1This is an example of a schematic cross-sectional view showing a manufacturing apparatus for producing the glass material of the present invention. The manufacturing apparatus 1 for the glass material has a molding die 10. The molding die 10 also functions as a melting container. The molding die 10 has a molding surface 10a and gas ejection holes 10b that open on the molding surface 10a. A plurality of gas ejection holes 10b are provided. In this way, the raw material block 12, molten glass, and glass material can be stably floated. In addition, a molding die having only one gas ejection hole 10b can also be used. The gas ejection hole 10b is connected to a gas supply mechanism 11 such as a gas cylinder. Gas is supplied from the gas supply mechanism 11 to the molding surface 10a via the gas ejection hole 10b. The type of gas is not particularly limited. For example, it can be air or oxygen, or it can be a reducing gas containing nitrogen, argon, helium, carbon monoxide gas, carbon dioxide gas, and hydrogen.

[0056] When manufacturing the glass material using the manufacturing apparatus 1, first, the raw material block 12 is placed on the molding surface 10a. The raw material block 12 is formed by integrating glass raw material powder through pressure molding or the like, and examples include a sintered body formed by integrating glass raw material powder through pressure molding or the like and then sintering, and an aggregate of crystals having the same composition as the target glass composition. In addition, the above sintered body can be cut or broken and used as the raw material block. Then, by ejecting gas from the gas ejection hole 10b, the raw material block 12 is floated on the molding surface 10a. That is, the raw material block 12 is held in a state of not contacting the molding surface 10a. In this state, laser is irradiated from the laser irradiation device 13 to the raw material block 12. Thereby, the raw material block 12 is heated and melted to obtain molten glass. After that, by cooling the molten glass, a glass material can be obtained. Preferably, during the melting process and the cooling process, gas is continuously ejected at least to prevent the raw material block 12, molten glass, and glass material from contacting the molding surface 10a. In addition to the method of irradiating laser, the heating method can also be radiant heating.

[0057] Examples of the material of the molding die include aluminum, aluminum-magnesium alloy, aluminum-silicon alloy, aluminum-magnesium-silicon alloy, aluminum-magnesium-zinc alloy, metallic silicon, stainless steel, duralumin, platinum, platinum-rhodium alloy, tungsten, tungsten alloy, zirconium, titanium, and titanium alloy. Among them, aluminum, aluminum-magnesium alloy, aluminum-silicon alloy, aluminum-magnesium-silicon alloy, and aluminum-magnesium-zinc alloy are preferred in terms of corrosion resistance and workability.

[0058] Examples

[0059] The present invention will be described below based on examples, but the present invention is not limited to the following examples.

[0060] Tables 1 to 4 show the examples (No. 2 to 4, 7, 8, 11 to 13, 16, 17, 20 to 22, 25, 26, 29 to 31, 34, 35) and comparative examples (No. 1, 5, 6, 9, 10, 14, 15, 18, 19, 23, 24, 27, 28, 32, 33, 36) of the present invention.

[0061] [Table 1]

[0062]

[0063] [Table 2]

[0064]

[0065] [Table 3]

[0066]

[0067] [Table 4]

[0068]

[0069] 0.3 to 0.6 g of the raw material powder prepared into the glass composition described in Tables 1 to 4 was press-molded, and a raw material block was produced by sintering at 900 to 1100 °C for 3 to 12 hours.

[0070] Using the raw material block obtained above, by means of Figure 1 the device, a glass material having a substantially spherical shape with a diameter of about 5 to 7 mm was produced by the containerless floating method. 1 to 4 units of 100W CO 2 laser oscillators were used as heat sources. The supply was carried out at a gas flow rate in the range of 1 to 15 L / min. 20 specimens were produced for each glass composition, and the devitrification product generation probability and refractive index (nd) were evaluated as follows.

[0071] Using a stereomicroscope (manufactured by Nikon Corporation, SMZ1000), observation was carried out at 10 times magnification to confirm the presence or absence of devitrification products inside the glass material. The case where the devitrification product generation probability (the ratio of the number of specimens with defects among 20 specimens) was 0 to 10% was judged as "○", the case where it exceeded 10 and was 20% or less was judged as "△", and the case where it exceeded 20% was judged as "×".

[0072] Regarding the refractive index, after bonding the glass material to a soda-lime glass plate substrate with a thickness of 5 mm, right-angle grinding was carried out, and using KPR-2000 manufactured by Shimadzu Corporation, the measured value of the d-ray (587.6 nm) of the helium lamp was evaluated.

[0073] As can be seen from Tables 1 to 4, the glass materials of the examples contain Al in a range exceeding 0 and being 500 ppm or less2 O 3 , and has excellent devitrification resistance. On the other hand, the glass materials of No. 1, 6, 10, 15, 19, 24, 28, 33 without Al 2 O 3 have poor devitrification resistance. In addition, for the glass materials of No. 5, 9, 14, 18, 23, 27, 32, 36 containing more than 500 ppm of Al 2 O 3 , the refractive index is slightly reduced, and the desired optical properties cannot be obtained.

Claims

1. A glass material, characterized in that: Having a refractive index of 2.0 or more and containing, in mol%, 10% or less of ZnO, 30 to 99% of Gd 2 O 3 +Y 2 O 3 +Yb 2 O 3 +Lu 2 O 3 +ZrO 2 +TiO 2 +Nb 2 O 5 +Ta 2 O 5 +WO 3 +Ga 2 O 3 +GeO 2 ,Al 2 O 3 and having a content of 80 ppm to 500 ppm.

2. The glass material according to claim 1, characterized in that: containing more than 0 and up to 68 mol% of La 2 O 3 、30% or more and less than 100% of Gd 2 O 3 +Y 2 O 3 +Yb 2 O 3 +Lu 2 O 3 +ZrO 2 +TiO 2 +Nb 2 O 5 +Ta 2 O 5 +WO 3 +Ga 2 O 3 +GeO 2 +B 2 O 3 +SiO 2 +P 2 O 5 。 3. The glass material according to claim 1 or 2, characterized in that: It is used as an optical element.

4. The glass material according to claim 1 or 2, characterized in that: It is used as an ornament.

5. A method for manufacturing a glass material for manufacturing the glass material according to any one of claims 1 to 4, the manufacturing method is characterized in that comprising: A step of heating and melting the raw material block to obtain molten glass by ejecting gas from a gas ejection hole opened on the molding surface of the molding die, floating the raw material block on the molding surface and maintaining it, and then cooling the molten glass.

Images