Optical glass, optical elements and optical instruments

Abstract

The present invention provides an optical glass, the composition of which, expressed as weight percentage, contains SiO2: 20% to 45%, B2O3: 18% to 38%, Nb2O5: 5% to 25%, ZrO2: 2% to 20%, and Na2O: 1% to 15%. By rationally designing the composition, it is possible to obtain optical glass having the desired refractive index and Abbe number of the present invention at low cost, and the glass of the present invention has low relative partial dispersion P g,F and negative anomalous dispersion, which meets the application of high-end optoelectronic products.

Description

[Technical field]

[0001] The present invention relates to optical glass, and more particularly to optical glass having a refractive index of 1.56 to 1.66 and an Abbe number of 40 to 48, and to an optical element and optical device produced from the same. [Background technology]

[0002] Optical glass is an important component of optoelectronic products. In recent years, with the rapid development of optoelectronic products such as smartphones, single-lens reflex cameras and security cameras, higher requirements are being placed on the performance of optical glass. For example, in optical design, it is desired that optical glass has the performance of properly eliminating or reducing the residual chromatic aberration of the secondary spectrum as much as possible, so that optical glass has a lower relative partial dispersion (P g,F ) and negative anomalous dispersion.

[0003] Optical glass having a refractive index in the range of 1.56 to 1.66 and an Abbe number in the range of 40 to 48 can be widely applied to various optical systems. In the prior art, optical glass in this range has a relative partial dispersion P g,F Therefore, it is difficult to meet the requirement of eliminating the residual chromatic aberration of the secondary spectrum. For example, CN103466936A discloses an optical glass having a refractive index of 1.50 or more and an Abbe number of 55 or less, which does not have negative anomalous dispersion, contains a high content of GeO2 composition, and has high raw material costs. Therefore, it is difficult to meet the requirement of eliminating the residual chromatic aberration of the secondary spectrum. g,F The development of optical glass having low optical transmittance, negative anomalous dispersion and low cost is of great significance to the development of the photoelectric field. Summary of the Invention [Problem to be solved by the invention]

[0004] The problem to be solved by the present invention is to reduce the relative partial variance (P g,F The object of the present invention is to provide an optical glass having low optical dispersion, negative anomalous dispersion, and low cost. [Means for solving the problem]

[0005] The means adopted by the present invention to solve the problems are as follows.

[0006] It is an optical glass and contains, in weight percentage, SiO2: 20% to 45%, B2O3: 18% to 38%, Nb2O5: 5% to 25%, ZrO2: 2% to 20%, and Na2O: 1% to 15%.

[0007] Furthermore, the optical glass has a composition expressed by weight percentage of MgO: 0 to 5%, and / or CaO: 0 to 10%, and / or SrO: 0 to 5%, and / or BaO: 0 to 5%, and / or Li2O: 0 to 5%, and / or K2O: 0 to 10%, and / or WO3: 0 to 5%, and / or Ta2O5: 0 to 12%, and / or TiO2: 0 to 5%, and / or ZnO : 0-5%, and / or Ln2O3: 0-5%, and / or Al2O3: 0-5%, and / or GeO2: 0-5%, and / or a fining agent: 0-1%, wherein the Ln2O3 is one or more of La2O3, Gd2O3, Y2O3, Yb2O3, and Lu2O3, and the fining agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0008] It is an optical glass whose composition, expressed as a weight percentage, is as follows: SiO2: 20% to 45%, B2O3: 18% to 38%, Nb2O5: 5% to 25%, ZrO2: 2% to 20%, Na2O: 1% to 15%, MgO: 0 to 5%, CaO: 0 to 10%, SrO: 0 to 5%, BaO: 0 to 5%, Li2O: 0 to 5%, K2O: 0 to 10%, WO3: 0 to 5%, Ta2O5: 0 The composition is composed of: 0-12%, TiO2: 0-5%, ZnO: 0-5%, Ln2O3: 0-5%, Al2O3: 0-5%, GeO2: 0-5%, and fining agent: 0-1%, wherein the Ln2O3 is one or more of La2O3, Gd2O3, Y2O3, Yb2O3, and Lu2O3, and the fining agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0009] Furthermore, the optical glass has a composition, expressed as a weight percentage, of B2O3 / SiO2 in the range of 0.51 to 1.6, preferably in the range of 0.6 to 1.5, more preferably in the range of 0.7 to 1.2, and even more preferably in the range of 0.75 to 1.0.

[0010] Furthermore, the optical glass has a composition, expressed as weight percentage, of Nb2O5 / B2O3 in a range of 0.15 to 1.0, preferably in a range of 0.2 to 0.9, more preferably in a range of 0.3 to 0.8, and even more preferably in a range of 0.4 to 0.7.

[0011] Furthermore, the optical glass has a composition, expressed as weight percentage, of B2O3 / (Nb2O5+ZrO2) in the range of 0.5 to 2.5, preferably B2O3 / (Nb2O5+ZrO2) in the range of 0.6 to 2.0, more preferably B2O3 / (Nb2O5+ZrO2) in the range of 0.7 to 1.5, and even more preferably B2O3 / (Nb2O5+ZrO2) in the range of 0.8 to 1.3.

[0012] Furthermore, when the composition of the optical glass is expressed as weight percentage, CaO / ZrO2 is 2.0 or less, preferably CaO / ZrO2 is 0.05 to 1.5, more preferably CaO / ZrO2 is 0.1 to 1.0, and even more preferably CaO / ZrO2 is 0.1 to 0.8.

[0013] Furthermore, the optical glass has a composition, expressed as a weight percentage, of 0.6 to 2.0 (SiO2+BaO) / B2O3, preferably 0.7 to 1.8 (SiO2+BaO) / B2O3, more preferably 0.8 to 1.6, and even more preferably 1.0 to 1.5 (SiO2+BaO) / B2O3.

[0014] Furthermore, in the optical glass, when the composition is expressed as a weight percentage, (Nb2O5+Na2O+BaO) / B2O3 is 0.5 to 1.5, preferably (Nb2O5+Na2O+BaO) / B2O3 is 0.65 to 0.95, more preferably (Nb2O5+Na2O+BaO) / B2O3 is 0.7 to 0.95, and even more preferably (Nb2O5+Na2O+BaO) / B2O3 is 0.7 to 0.9.

[0015] Furthermore, the optical glass has a composition, expressed as a weight percentage, of CaO / K2O in a range of 0.1 to 5.0, preferably 0.3 to 3.0, more preferably 0.5 to 2.5, and even more preferably 0.8 to 2.0.

[0016] Furthermore, the optical glass has a composition, expressed as a weight percentage, of 0.05 to 0.8 (CaO+K2O) / SiO2, preferably 0.05 to 0.6 (CaO+K2O) / SiO2, more preferably 0.1 to 0.5, and even more preferably 0.1 to 0.4 (CaO+K2O) / SiO2).

[0017] Furthermore, in the optical glass, when the composition is expressed as a weight percentage, (Li2O+Na2O+K2O) / B2O3 is 0.1 to 1.5, preferably (Li2O+Na2O+K2O) / B2O3 is 0.15 to 1.0, more preferably (Li2O+Na2O+K2O) / B2O3 is 0.2 to 0.9, and even more preferably (Li2O+Na2O+K2O) / B2O3 is 0.25 to 0.7.

[0018] Furthermore, the optical glass has a composition expressed by weight percentage of SiO2: 25% to 40%, preferably SiO2: 28% to 38%, and / or B2O3: 21% to 35%, preferably B2O3: 23% to 30%, and / or Nb2O5: 8% to 20%, preferably Nb2O5: 10% to 18%, and / or ZrO2: 5% to 18%, preferably ZrO2: 7% to 15%, and / or Na2 O: 3% to 13%, preferably Na2O: 5% to 12%, and / or MgO: 0 to 2%, preferably MgO: 0 to 1%, and / or CaO: 0.5 to 8%, preferably CaO: 1 to 6%, and / or SrO: 0 to 2%, preferably SrO: 0 to 1%, and / or BaO: 0 to 3%, preferably BaO: 0 to 2%, and / or Li2O: 0 to 3%, preferably Li2O: 0 to 2%, and / or or K2O: 0.5-8%, preferably K2O: 1-6%, and / or WO3: 0-3%, preferably WO3: 0-1%, and / or Ta2O5: 0-5%, preferably Ta2O5: 0-1%, and / or TiO2: 0-1%, and / or ZnO: 0-3%, preferably ZnO: 0-1%, and / or Ln2O3: 0-3%, preferably Ln2O3: 0-1%, and / or Al2O3: 0 The Ln2O3 is one or more of La2O3, Gd2O3, Y2O3, Yb2O3, and Lu2O3, and the fining agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0019] Furthermore, the optical glass has a composition that does not contain TiO2, and / or does not contain WO3, and / or does not contain Ta2O5, and / or does not contain GeO2, and / or does not contain ZnO, and / or does not contain Ln2O3, and / or does not contain Al2O3, and the Ln2O3 includes one or more of La2O3, Gd2O3, Y2O3, Yb2O3, and Lu2O3.

[0020] Furthermore, the refractive index n dis 1.56 to 1.66, preferably 1.58 to 1.65, more preferably 1.60 to 1.64, and / or the Abbe number v d is 40-48, preferably 41-47, and more preferably 42-46.

[0021] Furthermore, the relative partial dispersion P g,F is 0.7000 or less, preferably 0.6500 or less, more preferably 0.6000 or less, and / or the relative partial dispersion deviation value ΔP g,F is −0.0040 or less, preferably −0.0050 or less, more preferably −0.0060 or less, and even more preferably −0.0065 or less.

[0022] Furthermore, the density ρ of the optical glass is 3.0 g / cm 3 or less, preferably 2.90 g / cm 3 More preferably, it is 2.85 g / cm 3 and / or the thermal expansion coefficient α 100 / 300℃ is 95×10 -7 / K or less, preferably 90×10 -7 / K or less, and more preferably 85×10 -7 / K or less, and / or the transition temperature T g is 560° C. or less, preferably 550° C. or less, more preferably 540° C. or less, and / or λ 80 is 390 nm or less, and preferably, 80 is 380 nm or less, and more preferably, 80 is 370 nm or less, and / or λ5 is 350 nm or less, preferably λ5 is 340 nm or less, more preferably λ5 is 330 nm or less, and / or weather resistance CR is class 2 or more, preferably class 1, and / or Knoop hardness H K 450 x 10 7 Pa or more, preferably 480×10 7 Pa, more preferably 500×10 7 Pa and / or wear degree FA is 80 to 130, preferably 90 to 120, and more preferably 95 to 115.

[0023] A glass preform is made of the optical glass.

[0024] An optical element is made of the optical glass or made of the glass preform.

[0025] An optical instrument contains the optical glass and / or contains the optical element. Effect of the Invention

[0026] The beneficial effects of the present invention are that optical glass having the desired refractive index and Abbe number of the present invention can be obtained at low cost by rational composition design, and that the glass of the present invention has low relative partial dispersion (P g,F ) and negative anomalous dispersion, which meets the needs of high-end optoelectronic products. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0027] Hereinafter, the embodiments of the optical glass of the present invention will be described in detail, but the present invention is not limited to the following embodiments, and can be appropriately modified and practiced within the scope of the object of the present invention. Note that, although duplicated explanations may be omitted as appropriate, this does not limit the gist of the invention, and hereinafter, the optical glass of the present invention may be simply referred to as glass.

[0028] [Optical glass] The range of each composition (component) of the optical glass of the present invention will be explained below. In the present invention, unless otherwise specified, the content of each composition and the total content are all expressed as weight percentage (wt%), that is, the content of each composition and the total content are expressed as weight percentage with respect to the total amount of glass material of the oxide-equivalent composition. Here, the "composition in oxide equivalent" refers to the case where oxides, composite salts, hydroxides, etc. used as raw materials of the composition components of the optical glass of the present invention are decomposed and converted into oxides during melting, and the total amount of the oxide material is taken as 100%.

[0029] The numerical ranges described in the present invention include upper and lower limits, and "greater than" and "less than" include the endpoints, and all integers and fractions contained within the range, unless otherwise stated in a specific instance, and are not limited to the specific values ​​stated when the range is limited. As used herein, "and / or" is inclusive, for example, "A and / or B" means only A, or only B, or both A and B.

[0030] <Essential and optional ingredients> SiO2 has the effect of improving the chemical stability of glass, maintaining a suitable viscosity for molten glass, and reducing erosion of refractories. In the present invention, the above effect is obtained by including 20% ​​or more of SiO2, and preferably, the SiO2 content is 25% or more, and more preferably, the SiO2 content is 28% or more. If the SiO2 content is too high, the glass becomes more difficult to melt, which is disadvantageous for dissolving ZrO2 in the composition. Therefore, in the present invention, the upper limit of the SiO2 content is 45%, preferably 40%, and more preferably 38%.

[0031] B2O3 is advantageous in lowering the short-wave special dispersion of the glass, so that the glass has high negative anomalous dispersion performance. If the B2O3 content is less than 18%, the high-temperature viscosity of the glass is high, the melting performance is low, and the negative anomalous dispersion is unlikely to reach the design requirement. If the B2O3 content exceeds 38%, the chemical stability of the glass is low, and the glass is likely to devitrify. Therefore, the B2O3 content is 18% to 38%, preferably 21% to 35%, and more preferably 23% to 30%.

[0032] Through numerous experimental studies, the inventors have found that, in some embodiments, the ratio B2O3 / SiO2 between the content of B2O3 and the content of SiO2 is controlled within the range of 0.51 to 1.6, thereby making it possible to obtain a glass P g,F value and ΔP g,F It has been found that this is advantageous in lowering the value and obtaining a low transition temperature. Therefore, preferably, B2O3 / SiO2 is 0.51 to 1.6, and more preferably, B2O3 / SiO2 is 0.6 to 1.5. Furthermore, by controlling B2O3 / SiO2 within the range of 0.7 to 1.2, it is advantageous in obtaining an appropriate abrasion degree of the glass and improving the hardness of the glass. Therefore, more preferably, B2O3 / SiO2 is 0.7 to 1.2, and even more preferably, B2O3 / SiO2 is 0.75 to 1.0.

[0033] Nb2O5 is a high refractive index and high dispersion component that improves the refractive index and devitrification resistance of the glass, reduces the thermal expansion coefficient of the glass, and g,F Value and ΔP g,F In the present invention, the above effect can be obtained by containing 5% or more of Nb2O5, and the lower limit of the content of Nb2O5 is preferably 8%, more preferably 10%. If the content of Nb2O5 exceeds 25%, the thermal stability and weather resistance of the glass are reduced, and the light transmittance is reduced. Therefore, in the present invention, the upper limit of the content of Nb2O5 is 25%, preferably 20%, more preferably 18%.

[0034] In some embodiments, the ratio Nb2O5 / B2O3 between the content of Nb2O5 and the content of B2O3 is controlled within a range of 0.15 to 1.0, thereby reducing the P of the glass. g,F value and ΔP g,F It is possible to reduce the value and prevent a decrease in the light transmittance of the glass. Therefore, preferably, Nb2O5 / B2O3 is 0.15 to 1.0, and more preferably, Nb2O5 / B2O3 is 0.2 to 0.9. Furthermore, when Nb2O5 / B2O3 is in the range of 0.3 to 0.8, it is advantageous to reduce the thermal expansion coefficient and transition temperature of the glass. Therefore, more preferably, Nb2O5 / B2O3 is 0.3 to 0.8, and even more preferably, Nb2O5 / B2O3 is 0.4 to 0.7.

[0035] ZrO2 increases the refractive index of the glass and adjusts the special dispersion of short waves, decreasing the ΔP of the glass. g,F The value can be reduced, and the devitrification resistance and strength of the glass can be improved. In the present invention, the above effect can be obtained by containing 2% or more of ZrO2, and preferably contains 5% or more of ZrO2, and more preferably contains 7% or more of ZrO2. If the content of ZrO2 exceeds 20%, it becomes difficult to melt the glass, the melting temperature increases, inclusions enter the inside of the glass, and the light transmittance decreases. Therefore, the content of ZrO2 is 20% or less, preferably 18% or less, and more preferably 15% or less.

[0036] In some embodiments, the ratio B2O3 / (Nb2O5+ZrO2) between the content of B2O3 and the total content of Nb2O5 and ZrO2, Nb2O5+ZrO2, is controlled within a range of 0.5 to 2.5, thereby improving the P of the glass. g,F value and ΔP g、FIt is possible to reduce the value and prevent an increase in glass density. Therefore, preferably, B2O3 / (Nb2O5+ZrO2) is 0.5 to 2.5, and more preferably, B2O3 / (Nb2O5+ZrO2) is 0.6 to 2.0. Furthermore, by controlling B2O3 / (Nb2O5+ZrO2) within the range of 0.7 to 1.5, it is advantageous to improve the weather resistance and bubble content of the glass. Therefore, more preferably, B2O3 / (Nb2O5+ZrO2) is 0.7 to 1.5, and even more preferably, B2O3 / (Nb2O5+ZrO2) is 0.8 to 1.3.

[0037] Although MgO can reduce the refractive index and melting temperature of the glass, if the content of MgO is too high, the devitrification resistance and stability of the glass decrease and the cost of the glass increases. Therefore, the content of MgO is limited to 0 to 5%, preferably 0 to 2%, and more preferably 0 to 1%.

[0038] CaO contributes to adjusting the optical constants of the glass, improves the processing performance of the glass, and reduces the density of the glass, but if the CaO content is too high, the devitrification resistance of the glass decreases. Therefore, the CaO content is limited to 0 to 10%, preferably 0.5 to 8%, and more preferably 1 to 6%.

[0039] In some embodiments, by controlling the ratio CaO / ZrO2 between the CaO content and the ZrO2 content to 2.0 or less, the glass has an appropriate degree of abrasion and prevents the deterioration of the devitrification resistance of the glass. Therefore, preferably, CaO / ZrO2 is 2.0 or less. Furthermore, by controlling CaO / ZrO2 within the range of 0.05 to 1.5, it is advantageous to improve the weather resistance and alkali resistance of the glass. Therefore, more preferably, CaO / ZrO2 is 0.05 to 1.5, even more preferably, CaO / ZrO2 is 0.1 to 1.0, and even more preferably, CaO / ZrO2 is 0.1 to 0.8.

[0040] Although SrO can adjust the refractive index and Abbe number of the glass, if the content is too high, the chemical stability of the glass decreases and the cost of the glass increases rapidly. Therefore, the SrO content is limited to 0 to 5%, preferably 0 to 2%, and more preferably 0 to 1%.

[0041] BaO can increase the devitrification resistance and hardness of the glass and decrease the refractive index temperature coefficient and thermal expansion coefficient of the glass. However, if the BaO content is high, the weather resistance and chemical stability of the glass decrease. Therefore, the BaO content is 5% or less, preferably 3% or less, and more preferably 2% or less.

[0042] In some embodiments, the ratio (SiO2+BaO) / B2O3 between the total content of SiO2 and BaO (SiO2+BaO) and the content of B2O3 is controlled within the range of 0.6 to 2.0, thereby optimizing the hardness and abrasion resistance of the glass and preventing an increase in the transition temperature of the glass. Therefore, preferably, (SiO2+BaO) / B2O3 is 0.6 to 2.0, more preferably, (SiO2+BaO) / B2O3 is 0.7 to 1.8, even more preferably, (SiO2+BaO) / B2O3 is 0.8 to 1.6, and even more preferably, (SiO2+BaO) / B2O3 is 1.0 to 1.5.

[0043] Li2O can lower the glass transition temperature, adjust the high-temperature viscosity of glass, and improve the melting property of glass, but a high content of Li2O is disadvantageous to the stability and cost-effectiveness of glass. Therefore, in the present invention, the content of Li2O is 5% or less, preferably 3% or less, and more preferably 2% or less.

[0044] Na2O has the effect of improving the meltability of glass, and can enhance the glass melting effect. g,F value and ΔP g,FWhen the Na2O content exceeds 15%, the chemical stability and weather resistance of the glass decrease. Therefore, the Na2O content is 1% to 15%, preferably the Na2O content is 3% to 13%, and more preferably the Na2O content is 5% to 12%.

[0045] In some embodiments, the ratio (Nb2O5+Na2O+BaO) / B2O3 between the total content of Nb2O5, Na2O, and BaO (Nb2O5+Na2O+BaO) and the content of B2O3 is controlled within a range of 0.5 to 1.5, thereby improving the P content of the glass. g,F value and ΔP g,F The value of the glass composition can be reduced, and the thermal expansion coefficient of the glass can be reduced. Therefore, preferably, (Nb2O5+Na2O+BaO) / B2O3 is 0.5 to 1.5. Furthermore, by controlling (Nb2O5+Na2O+BaO) / B2O3 within the range of 0.65 to 0.95, it is advantageous to improve the hardness and weather resistance of the glass. Therefore, more preferably, (Nb2O5+Na2O+BaO) / B2O3 is 0.65 to 0.95, even more preferably, (Nb2O5+Na2O+BaO) / B2O3 is 0.7 to 0.95, and even more preferably, (Nb2O5+Na2O+BaO) / B2O3 is 0.7 to 0.9.

[0046] K2O has the effect of improving the thermal stability and meltability of glass, but if its content exceeds 10%, the devitrification resistance and chemical stability of the glass decrease. Therefore, in the present invention, the K2O content is 10% or less, preferably, the K2O content is 0.5% to 8%, and more preferably, the K2O content is 1% to 6%.

[0047] In some embodiments, the ratio CaO / K2O between the CaO content and the K2O content is controlled within the range of 0.1 to 5.0, thereby improving the devitrification resistance of the glass and decreasing the density of the glass. Therefore, preferably, CaO / K2O is 0.1 to 5.0, and more preferably, 0.3 to 3.0. Furthermore, by controlling CaO / K2O within the range of 0.5 to 2.5, it is advantageous to decrease the thermal expansion coefficient of the glass and optimize the striae of the glass. Therefore, more preferably, CaO / K2O is 0.5 to 2.5, and even more preferably, 0.8 to 2.0.

[0048] In some embodiments, the ratio (CaO+K2O) / SiO2 between the total content of CaO and K2O (CaO+K2O) and the content of SiO2 is controlled within the range of 0.05 to 0.8, so that the glass can obtain an appropriate abrasion resistance and excellent striae. Therefore, preferably, (CaO+K2O) / SiO2 is 0.05 to 0.8, and more preferably, (CaO+K2O) / SiO2 is 0.05 to 0.6. Furthermore, by controlling (CaO+K2O) / SiO2 within the range of 0.1 to 0.5, it is advantageous to improve the light transmittance and hardness of the glass. Therefore, more preferably, (CaO+K2O) / SiO2 is 0.1 to 0.5, and even more preferably, (CaO+K2O) / SiO2 is 0.1 to 0.4.

[0049] In some embodiments, the ratio (Li2O+Na2O+K2O) / B2O3 between the total content of alkali metal oxides Li2O+Na2O+K2O and the content of B2O3 is controlled within the range of 0.1 to 1.5, thereby lowering the transition temperature and density of the glass and improving the light transmittance of the glass. Therefore, preferably, (Li2O+Na2O+K2O) / B2O3 is 0.1 to 1.5, more preferably, (Li2O+Na2O+K2O) / B2O3 is 0.15 to 1.0, even more preferably, (Li2O+Na2O+K2O) / B2O3 is 0.2 to 0.9, and even more preferably, (Li2O+Na2O+K2O) / B2O3 is 0.25 to 0.7.

[0050] WO3 can increase the refractive index and mechanical strength of glass, and if the content of WO3 exceeds 5%, the thermal stability of glass decreases and the devitrification resistance decreases. Therefore, the upper limit of the content of WO3 is 5%, preferably 3%, and more preferably 1%. In some embodiments, it is more preferable that WO3 is not contained.

[0051] Ta2O5 has the effect of increasing the refractive index and improving the devitrification resistance of the glass, but if the content is too high, the thermal stability of the glass decreases, the density increases, and it becomes difficult to control the optical constants within the desired range. On the other hand, Ta2O5 is very expensive compared to other components, and from the viewpoint of practical use and economy, it is necessary to reduce the amount of Ta2O5 used as much as possible. Therefore, in the present invention, the content of Ta2O5 is limited to 0 to 12%, preferably 0 to 5%, more preferably 0 to 1%, and even more preferably, Ta2O5 is not contained.

[0052] GeO2 has the effect of improving the refractive index and devitrification resistance, but if its content is too high, the chemical stability of the glass decreases, making it difficult to control the optical constants within the desired range. On the other hand, compared with other components, GeO2 is very expensive, and from the viewpoint of practical use and economy, it is necessary to reduce its usage amount as much as possible. Therefore, in the present invention, the content of GeO2 is limited to 0 to 5%, preferably 0 to 3%, more preferably 0 to 1%, and further preferably, GeO2 is not contained.

[0053] TiO2 has the effect of increasing the refractive index and dispersion of glass, and when contained in an appropriate amount, it can make glass more stable and reduce the viscosity of glass. If the TiO2 content exceeds 5%, the crystallization tendency of glass increases, the transition temperature rises, and the P of glass decreases. g,F Value and ΔP g,FTherefore, in the present invention, the content of TiO2 is 5% or less, preferably 1% or less, and more preferably, no TiO2 is contained.

[0054] ZnO can adjust the refractive index and dispersion of glass, reduce the high-temperature viscosity and transition temperature of glass, melt glass at a low temperature, and improve the light transmittance of glass. If the ZnO content is too high, the glass becomes more difficult to mold, the devitrification resistance decreases, and it is disadvantageous in obtaining negative anomalous dispersion of glass. Therefore, the ZnO content is 0 to 5%, preferably 0 to 3%, and more preferably 0 to 1%. In some embodiments, it is more preferable that ZnO is not contained.

[0055] Ln2O3 (Ln2O3 is one or more of La2O3, Gd2O3, Y2O3, Yb2O3, and Lu2O3) is a component that improves the refractive index and chemical stability of glass, and by controlling the Ln2O3 content to 5% or less, it is possible to prevent a decrease in the devitrification resistance of the glass, and the upper limit of the Ln2O3 content range is preferably 3%, and more preferably 1%. In some embodiments, it is even more preferable that Ln2O3 is not contained.

[0056] Although Al2O3 can improve the chemical stability of glass, if its content exceeds 5%, the melting property and light transmittance of glass decrease. Therefore, in the present invention, the content of Al2O3 is 0 to 5%, preferably 0 to 3%, and more preferably 0 to 1%. In some embodiments, it is more preferable that Al2O3 is not contained.

[0057] In the present invention, the clarification effect of glass can be improved by containing one or more components selected from 0 to 1% of Sb2O3, SnO, SnO2, and CeO2 as a clarifier, and the content of the clarifier is preferably 0 to 0.8%, more preferably 0 to 0.5%. If the content of Sb2O3 exceeds 1%, the clarification performance of glass tends to decrease, and its strong oxidizing effect promotes corrosion of the platinum or platinum alloy container for melting the glass and deterioration of the molding die, so in the present invention, the content of Sb2O3 is preferably 0 to 1%, more preferably 0 to 0.5%. SnO and SnO2 may be used as clarifiers, but if the content exceeds 1%, the coloring tendency of glass increases, and when the glass is heated, softened, and remolded by press molding, Sn tends to become the starting point of crystal nucleation and devitrification occurs. Therefore, the content of SnO2 in the present invention is preferably 0-1%, more preferably 0-0.5%, and the content of SnO is preferably 0-1%, more preferably 0-0.5%. The function and content ratio of CeO2 are the same as those of SnO2, and the content is preferably 0-1%, more preferably 0-0.5%, and even more preferably CeO2 is not contained.

[0058] <Prohibited ingredients> In the glass of the present invention, even when oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo are contained alone or in combination in small amounts, the glass is colored and absorption occurs at specific wavelengths in the visible light region, thereby weakening the property of the present invention of improving the visible light transmittance effect. Therefore, it is preferable that these oxides are not substantially contained in optical glass, particularly in optical glass that is required to have transmittance at wavelengths in the visible light region.

[0059] In recent years, there has been a trend to refrain from using oxides of Th, Cd, Tl, Os, Be and Se as harmful chemical substances, and measures to protect the environment are required not only in the glass manufacturing process, but also in the processing process and disposal after commercialization. Therefore, when the impact on the environment is important, it is preferable that they are not substantially contained except for unavoidable contamination. This makes the optical glass substantially free of substances that pollute the environment. Therefore, the optical glass of the present invention can be manufactured, processed and disposed of without taking special measures for environmental protection.

[0060] Due to environmental considerations, the optical glass of the present invention preferably does not contain As2O3 and PbO.

[0061] The terms "not contained" and "0%" used in this specification mean that the relevant compound, molecule, element, etc. is not intentionally added to the optical glass of the present invention as a raw material. However, there may be some impurities or components that are not intentionally added to the raw materials and / or equipment used to produce the optical glass, and these may be contained in small or trace amounts in the final optical glass. Such cases also fall within the scope of protection of the patent of the present invention.

[0062] The performance of the optical glass of the present invention will now be described.

[0063] <Refractive index and Abbe number> The refractive index of optical glass (n d ) and Abbe number (v d ) is tested in accordance with the method specified in GB / T7962.1-2010.

[0064] In some embodiments, the refractive index (n d The lower limit of the refractive index (n d ) is 1.66, preferably 1.65, and more preferably 1.64.

[0065] In some embodiments, the Abbe number (ν d ) is 40, preferably 41, and more preferably 42. In some embodiments, the lower limit of the Abbe number (ν d ) is 48, preferably 47, and more preferably 46.

[0066] <density> The density (ρ) of optical glass is tested according to the method specified in GB / T7962.20-2010.

[0067] In some embodiments, the optical glass of the present invention has a density (ρ) of 3.0 g / cm 3 or less, preferably 2.90 g / cm 3 More preferably, it is 2.85 g / cm 3 The following is the result.

[0068] <Thermal expansion coefficient> Thermal expansion coefficient of optical glass (α 100 / 300℃ ) tests data from 100℃ to 300℃ according to the method specified in GB / T7962.16-2010.

[0069] In some embodiments, the optical glass of the present invention has a coefficient of thermal expansion (α 100 / 300℃ ) is 95 x 10 -7 / K or less, preferably 90×10 -7 / K or less, and more preferably 85×10 -7 / K or less.

[0070] <Transition temperature> Transition temperature of optical glass (T g ) is tested in accordance with the method specified in GB / T7962.16-2010.

[0071] In some embodiments, the optical glass of the present invention has a transition temperature (T g ) is 560° C. or less, preferably 550° C. or less, and more preferably 540° C. or less.

[0072] <Coloring degree> The short-wave transmission spectrum characteristics of the glass of the present invention are 80 and λ5). 80 λ means the corresponding wavelength when the glass transmittance reaches 80%. 80 The measurement is carried out by measuring the spectral transmittance in the wavelength range of 280 nm to 700 nm using a glass (thickness 10 ± 0.1 mm) having two parallel, optically polished, opposing flat surfaces, and using a wavelength that shows a transmittance of 80%. The so-called spectral transmittance or transmittance is the intensity I in The light is incident vertically and passes through the glass with intensity I out When light of I is emitted, out / I in This is the transmittance including the surface reflection loss at the above-mentioned surface of the glass. The higher the refractive index of the glass, the greater the surface reflection loss. Therefore, in high refractive index glass, λ 80 A small value means that the coloring of the glass itself is extremely small and the light transmittance is high.

[0073] In some embodiments, the λ 80 is 390 nm or less, preferably 380 nm or less, and more preferably 370 nm or less.

[0074] In some embodiments, the λ5 of the optical glass of the present invention is 350 nm or less, preferably 340 nm or less, and more preferably 330 nm or less.

[0075] <Weather resistance> The weather resistance (CR) test method for optical glass is as follows: The sample is placed in a test box with a saturated water vapor atmosphere of 90% relative humidity, and circulated at 40-50°C every hour for 15 cycles. The weather resistance class is determined by the amount of turbidity change before and after leaving the sample, and the weather resistance classification is shown in Table 1.

[0076] [Table 1]

[0077] In some embodiments, the weatherability (CR) of the optical glass of the present invention is Class 2 or higher, and preferably Class 1.

[0078] <Knoop hardness> Knoop hardness of optical glass (H K ) is tested in accordance with the test methods specified in GB / T7962.18-2010.

[0079] In some embodiments, the optical glass of the present invention has a Knoop hardness (H K ) is 450 x 10 7 Pa or more, preferably 480×10 7 Pa or more, more preferably 500×10 7 Pa or more.

[0080] <Relative partial variance and relative partial variance deviation value> Relative partial variance (P g,F ) and relative partial variance deviation (ΔP g,F The origin of is explained in the following formula.

[0081] The relative partial dispersion for wavelengths x and y is expressed by the following formula (1).

[0082] P x,y =(n x -n y ) / (n F -n C ) (1) From the Abbe number formula, the following formula (2) holds for many so-called "normal glasses" (hereinafter, H-K6 and F4 are selected as "normal glasses").

[0083] P x,y =m x,y ·v d +b x,y (2) Such a linear relationship is x,y is the ordinate, v dis expressed as the abscissa, where m x,y is the slope, and b x,y is the intercept.

[0084] As is well known, the correction of the secondary spectrum, i.e., the achromatization for two or more wavelengths, requires the correction of at least one glass that does not conform to the above formula (2) (i.e., its P x,y The deviation value from the Abbe number empirical formula is required, and the deviation value is ΔP x,y When expressed as x,y -v d ΔP relative to the "normal line" where the points fit the above equation (2) x,y Thus, the ΔP of each glass x,y The value is calculated using the following formula (3).

[0085] P x,y =m x,y ·v d +b x,y +ΔP x,y (3) Therefore, ΔP x,y indicates quantitatively the deviation characteristic of special dispersion when compared with "normal glass".

[0086] Therefore, the relative partial variance (P g,F ) and relative partial variance deviation (ΔP g,F The calculation formulas for (a) are the following formulas (4) and (5).

[0087] P g,F =(n g -n F ) / (n F -n C ) (4) ΔP g,F =P g,F -0.6457+0.001703v d (5) In some embodiments, the optical glasses of the present invention have a relative partial dispersion (P g,F ) is 0.7000 or less, preferably 0.6500 or less, and more preferably 0.6000 or less.

[0088] In some embodiments, the optical glass of the present invention has a relative partial dispersion deviation value (ΔP g,F ) is −0.0040 or less, preferably −0.0050 or less, more preferably −0.0060 or less, and even more preferably −0.0065 or less.

[0089] <Abrasion level> Abrasion rate of optical glass (F A ) is the ratio of the amount of wear of the sample to the amount of wear (volume) of the standard sample (K9 glass) multiplied by 100 under the same conditions, and is expressed by the following formula.

[0090] F A =V / V0×100=(W / ρ) / (W0 / ρ0)×100 Where V is the volumetric wear of the test sample; V0 - volumetric wear volume of the standard sample; W - mass wear of the test sample; W0 - mass wear amount of the standard sample; ρ - density of the test sample, ρ0 - density of the standard sample.

[0091] In some embodiments, the optical glass of the present invention has a wear rate (F A ) is 80, preferably 90, more preferably 95, and the abrasion degree (F A ) is 130, preferably 120, and more preferably 115.

[0092] [Method of manufacturing optical glass] The method for producing the optical glass of the present invention is as follows. The glass of the present invention is produced using ordinary raw materials and processes, and raw materials including, but not limited to, oxides, hydroxides, fluorides, complex salts (e.g., carbonates, nitrates, phosphates, metaphosphates, etc.), boric acid, etc. are used, and the raw materials are mixed in an ordinary manner, and then the mixed furnace material is put into a melting furnace (e.g., platinum or platinum alloy crucible) at 1200°C to 1500°C for melting, and after clarification and homogenization, a homogeneous molten glass without bubbles or undissolved substances is obtained, and this molten glass is cast into a mold and annealed to produce the glass. Those skilled in the art can appropriately select the raw materials, process methods, and process parameters according to actual needs.

[0093] [Glass preforms and optical elements] From the produced optical glass, a glass preform can be produced by, for example, direct gob molding, polishing, or press molding such as hot press molding. That is, a glass preform can be produced by directly subjecting molten optical glass to precision gob molding to produce a precision glass preform, by subjecting the glass to mechanical processing such as grinding and polishing to produce a glass preform, or by producing a preform for press molding from optical glass, re-hot press molding the preform, and then polishing the preform. The means for producing a glass preform are not limited to the above means.

[0094] As described above, the optical glass of the present invention is useful for various optical elements and optical designs, and it is particularly preferable to form a preform from the optical glass of the present invention and use the preform to carry out reheat press molding, precision press molding, or the like to produce optical elements such as lenses and prisms.

[0095] The glass preform and optical element of the present invention are both formed from the optical glass of the present invention. The glass preform of the present invention has the excellent properties of optical glass, and the optical element of the present invention has the excellent properties of optical glass, making it possible to provide optical elements such as various lenses and prisms with high optical value.

[0096] Examples of the lens include various lenses whose lens surfaces are spherical or aspherical, such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens, and a plano-concave lens.

[0097] [Optical equipment] Optical elements formed from the optical glass of the present invention can be used to manufacture optical devices such as camera devices, imaging devices, projection devices, display devices, in-vehicle devices, and monitoring devices.

[0098] Working Example <Examples of optical glass> In order to more clearly interpret and explain the technical solutions of the present invention, the following non-limiting examples are provided.

[0099] In the present examples, the above-mentioned optical glass manufacturing method is used to obtain optical glasses having the compositions shown in Tables 2 to 4. In addition, the properties of each glass are measured by the test methods described in the present invention, and the measurement results are shown in Tables 2 to 4.

[0100] [Table 2] TIFF2025514420000003.tif84168

[0101] [Table 3] TIFF2025514420000005.tif73168

[0102] [Table 4] TIFF2025514420000007.tif75168

[0103] <Example of glass preform> From the glasses obtained in Examples 1 to 24 of the optical glass, various lenses such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, plano-concave lenses, and preforms such as prisms are manufactured using, for example, polishing means or press molding means such as reheat press molding and precision press molding.

[0104] <Examples of optical elements> The preform obtained in the above glass preform example is annealed to finely adjust the refractive index while reducing the stress inside the glass so that the optical properties such as the refractive index become the desired values.

[0105] Next, each preform is ground and polished to produce various lenses and prisms, such as a concave meniscus lens, a convex meniscus lens, a biconvex lens, a biconcave lens, a plano-convex lens, a plano-concave lens, etc. An anti-reflection film can also be applied to the surface of the obtained optical element.

[0106] <Examples of optical equipment> Optical elements manufactured from the above optical element embodiments can be used in optical designs to form optical components or optical assemblies using one or more optical elements, for example for use in imaging equipment, sensors, microscopes, medical technology, digital projection, communications, optical communication technology / information transmission, optics / illumination in the automotive field, lithography technology, excimer lasers, wafers, computer chips, and integrated circuits and electronic devices containing such circuits and chips.

Claims

1. The composition expressed in weight percentage is SiO ２ :20%~45%, B ２ O ３ :18%~38%, Nb ２ O ５ :5% to 25%, ZrO ２ : 2% to 20%, and Na ２ An optical glass containing 1% to 15% O.

2. The composition expressed in weight percentage is: MgO: 0-5%, and / or CaO: 0-10%, and / or SrO: 0-5%, and / or BaO: 0-5%, and / or Li ２ O: 0 to 5% and / or K ２ O: 0 to 10% and / or WO ３ : 0 to 5%, and / or Ta ２ O ５ : 0 to 12%, and / or TiO ２ : 0 to 5%, and / or ZnO: 0 to 5%, and / or Ln ２ O ３ : 0 to 5%, and / or Al ２ O ３ : 0 to 5%, and / or GeO ２ : 0 to 5%, and / or fining agent: 0 to 1%, ２ O ３ Is La ２ O ３ , Gd ２ O ３ , Y ２ O ３ , Yb ２ O ３ , Lu ２ O ３ The fining agent is one or more of Sb ２ O ３ , SnO, SnO ２ , CeO ２ 2. The optical glass according to claim 1, characterized in that the optical glass is one or more of the following:

3. The composition expressed in weight percentage is SiO ２ :20%~45%, B ２ O ３ :18%~38%, Nb ２ O ５ :5% to 25%, ZrO ２ :2%~20%, Na ２ O: 1% to 15%, MgO: 0 to 5%, CaO: 0 to 10%, SrO: 0 to 5%, BaO: 0 to 5%, Li ２ O: 0-5%, K ２ O: 0-10%, WO ３ : 0 to 5%, Ta ２ O ５ :0~12%, TiO ２ :0~5%, ZnO:0~5%, Ln ２ O ３ : 0 to 5%, Al ２ O ３ : 0-5%, GeO ２ : 0 to 5%, and clarifier: 0 to 1%, ２ O ３ Is La ２ O ３ , Gd ２ O ３ , Y ２ O ３ , Yb ２ O ３ , Lu ２ O ３ The fining agent is one or more of Sb ２ O ３ , SnO, SnO ２ , CeO ２ The optical glass is characterized in that it is one or more of the following:

4. When the composition is expressed in weight percentage, B ２ O ３ / SiO ２ is 0.51 to 1.6, preferably B ２ O ３ / SiO ２ is 0.6 to 1.5, and more preferably, B ２ O ３ / SiO ２ is 0.7 to 1.2, and more preferably B ２ O ３ / SiO ２ 4. The optical glass according to claim 1, wherein the refractive index is 0.75 to 1.

0.

5. The composition expressed in weight percentage is Nb ２ O ５ / B ２ O ３ is 0.15 to 1.0, preferably Nb ２ O ５ / B ２ O ３ is 0.2 to 0.9, and more preferably, Nb ２ O ５ / B ２ O ３ is 0.3 to 0.8, and more preferably, Nb ２ O ５ / B ２ O ３ 4. The optical glass according to claim 1, wherein the refractive index is 0.4 to 0.

7.

6. When the composition is expressed in weight percentage, B ２ O ３ / (Nb ２ O ５ + ZrO ２ ) is 0.5 to 2.5, and preferably B ２ O ３ / (Nb ２ O ５ + ZrO ２ ) is 0.6 to 2.0, and more preferably, B ２ O ３ / (Nb ２ O ５ + ZrO ２ ) is 0.7 to 1.5, and more preferably B ２ O ３ / (Nb ２ O ５ + ZrO ２ 4. The optical glass according to claim 1, wherein the refractive index is 0.8 to 1.

3.

7. The composition expressed as a weight percentage is CaO / ZrO ２ is 2.0 or less, and preferably, CaO / ZrO ２ is 0.05 to 1.5, and more preferably, CaO / ZrO ２ is 0.1 to 1.0, and more preferably, CaO / ZrO ２ 4. The optical glass according to claim 1, wherein the refractive index is 0.1 to 0.

8.

8. The composition expressed in weight percentage is (SiO ２ +BaO) / B ２ O ３ is 0.6 to 2.0, and preferably (SiO ２ +BaO) / B ２ O ３ is 0.7 to 1.8, and more preferably (SiO ２ +BaO) / B ２ O ３ is 0.8 to 1.6, and more preferably (SiO ２ +BaO) / B ２ O ３ 4. The optical glass according to claim 1, wherein the refractive index is 1.0 to 1.

5.

9. When the composition is expressed in weight percentage, (Nb ２ O ５ +Na ２ O+BaO) / B ２ O ３ is 0.5 to 1.5, preferably (Nb ２ O ５ +Na ２ O+BaO) / B ２ O ３ is 0.65 to 0.95, and more preferably, (Nb ２ O ５ +Na ２ O+BaO) / B ２ O ３ is 0.7 to 0.95, and more preferably, (Nb ２ O ５ +Na ２ O+BaO) / B ２ O ３ 4. The optical glass according to claim 1, wherein the refractive index is 0.7 to 0.

9.

10. The composition expressed as a weight percentage is CaO / K ２ O is 0.1 to 5.0, preferably CaO / K ２ O is 0.3 to 3.0, and more preferably, CaO / K ２ O is 0.5 to 2.5, and more preferably, CaO / K ２ 4. The optical glass according to claim 1, wherein O is 0.8 to 2.

0.

11. The composition expressed in weight percentage is (CaO + K ２ O) / SiO ２ is 0.05 to 0.8, and preferably (CaO+K ２ O) / SiO ２ is 0.05 to 0.6, and more preferably (CaO+K ２ O) / SiO ２ is 0.1 to 0.5, and more preferably (CaO+K ２ O) / SiO ２ 4. The optical glass according to claim 1, wherein the refractive index is 0.1 to 0.

4.

12. When the composition is expressed in weight percentage, (Li ２ O+Na ２ O+K ２ O) / B ２ O ３ is 0.1 to 1.5, preferably (Li ２ O+Na ２ O+K ２ O) / B ２ O ３ is 0.15 to 1.0, and more preferably (Li ２ O+Na ２ O+K ２ O) / B ２ O ３ is 0.2 to 0.9, and more preferably (Li ２ O+Na ２ O+K ２ O) / B ２ O ３ 4. The optical glass according to claim 1, wherein the refractive index is 0.25 to 0.

7.

13. The composition expressed in weight percentage is SiO ２ : 25% to 40%, preferably SiO ２ : 28% to 38%, and / or B ２ O ３ : 21% to 35%, preferably B ２ O ３ : 23% to 30%, and / or Nb ２ O ５ : 8% to 20%, preferably Nb ２ O ５ : 10% to 18%, and / or ZrO ２ : 5% to 18%, preferably ZrO ２ : 7% to 15%, and / or Na ２ O: 3% to 13%, preferably Na ２ O: 5% to 12%, and / or MgO: 0 to 2%, preferably MgO: 0 to 1%, and / or CaO: 0.5% to 8%, preferably CaO: 1 to 6%, and / or SrO: 0 to 2%, preferably SrO: 0 to 1%, and / or BaO: 0 to 3%, preferably BaO: 0 to 2%, and / or Li ２ O: 0 to 3%, preferably Li ２ O: 0 to 2% and / or K ２ O: 0.5 to 8%, preferably K ２ O: 1% to 6%, and / or WO ３ : 0 to 3%, preferably WO ３ : 0 to 1%, and / or Ta ２ O ５ : 0 to 5%, preferably Ta ２ O ５ : 0 to 1%, and / or TiO ２ : 0-1%, and / or ZnO: 0-3%, preferably ZnO: 0-1%, and / or Ln ２ O ３ : 0 to 3%, preferably Ln ２ O ３ : 0 to 1%, and / or Al ２ O ３ : 0 to 3%, preferably Al ２ O ３ : 0 to 1%, and / or GeO ２ : 0 to 3%, preferably GeO ２ : 0 to 1%, and / or fining agent: 0 to 0.8%, preferably, fining agent: 0 to 0.5%, and the Ln ２ O ３ Is La ２ O ３ , Gd ２ O ３ , Y ２ O ３ , Yb ２ O ３ , Lu ２ O ３ The fining agent is one or more of Sb ２ O ３ , SnO, SnO ２ , CeO ２ 4. The optical glass according to claim 1, wherein the optical glass is one or more of the following:

14. The composition is TiO ２ and / or WO ３ and / or does not contain Ta ２ O ５ and / or GeO ２ and / or does not contain ZnO and / or does not contain Ln ２ O ３ and / or Al ２ O ３ does not contain Ln ２ O ３ Is La ２ O ３ , Gd ２ O ３ , Y ２ O ３ , Yb ２ O ３ , Lu ２ O ３ 4. The optical glass according to claim 1, further comprising one or more of the following:

15. The refractive index n of the optical glass ｄ is 1.56 to 1.66, preferably 1.58 to 1.65, more preferably 1.60 to 1.64, and / or the Abbe number v ｄ The optical glass according to any one of claims 1 to 3, wherein is 40 to 48, preferably 41 to 47, and more preferably 42 to 46.

16. The relative partial dispersion P of the optical glass ｇ，Ｆ is 0.7000 or less, preferably 0.6500 or less, more preferably 0.6000 or less, and / or the relative partial dispersion deviation value ΔP ｇ，Ｆ is not more than −0.0040, preferably not more than −0.0050, more preferably not more than −0.0060, and even more preferably not more than −0.0065.

17. The density ρ of the optical glass is 3.0 g / cm ３ or less, preferably 2.90 g / cm ３ More preferably, 2.85 g / cm ３ and / or a thermal expansion coefficient α １００／３００℃ is 95 x 10 －７ / K or less, preferably 90×10 －７ / K or less, and more preferably 85×10 －７ / K or less, and / or the transition temperature T ｇ is 560° C. or less, preferably 550° C. or less, more preferably 540° C. or less, and / or λ ８０ is 390 nm or less, and preferably, ８０ is 380 nm or less, and more preferably, ８０ is 370 nm or less, and / or λ ５ is 350 nm or less, and preferably, ５ is 340 nm or less, and more preferably, ５ and / or the weather resistance CR is class 2 or higher, preferably class 1, and / or the Knoop hardness H Ｋ is 450 x 10 ７ Pa or more, preferably 480×10 ７ Pa, and more preferably 500×10 ７ Pa and / or wear degree F Ａ The optical glass according to any one of claims 1 to 3, wherein the refractive index is 80-130, preferably 90-120, and more preferably 95-115.

18. A glass preform, characterized in that it is made of the optical glass according to any one of claims 1 to 17.

19. An optical element, characterized in that it is manufactured from the optical glass according to any one of claims 1 to 17, or from the glass preform according to claim 18.

20. An optical instrument comprising the optical glass according to any one of claims 1 to 17 and / or the optical element according to claim 19.

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