Optical glass, optical elements and optical equipment

Abstract

The present invention provides an optical glass containing the following components by weight: SiO2: 1-12%, B2O3: 5-18%, La2O3: 40-60%, Y2O3: 4-20%, ZrO2: 1-12%, Nb2O5: 4-20%, and TiO2: 4-18%. By rationally designing the components, the present invention enables the production of optical glass with excellent devitrification resistance at lower raw material costs.

Description

[Technical Field]

[0001] The present invention relates to optical glass, and more particularly to optical glass having a refractive index of 1.92 to 1.98 and an Abbe number of 29 to 36, and to optical elements and optical instruments manufactured from the same. [Background technology]

[0002] In recent years, advances in science and technology have led to the continuous upgrading of optoelectronic information products, resulting in an ever-increasing demand for optical glass, and increasingly stringent performance requirements for optical glass. For the same radius of curvature, the higher the refractive index of the glass, the larger the imaging field that can be obtained. As optical devices become increasingly miniaturized, the demand for high refractive index glass is on the rise. Optical glass with a refractive index of 1.92 to 1.98 and an Abbe number of 29 to 36 has a relatively high refractive index, making it easy to achieve miniaturization, ultra-thinness, and wide-angle lenses, and its application scenarios are widespread. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Chinese Patent Application Publication No. 110128005 [Patent Document 2] Japanese Patent Application Publication No. 2019-11232 Summary of the Invention [Problem to be solved by the invention]

[0004] Because there is a high demand for high refractive index optical glass, it is desirable to be able to produce it at lower raw material costs in order to increase sustainable supply capacity. Patent Document 1 (China Patent Application Publication No. 110128005) discloses high refractive index optical glass with a refractive index of 1.87 or more and an Abbe number of 40 or less, but the glass contains large amounts of Gd2O3 and WO3, which makes it difficult to control costs. Patent Document 2 (Japanese Patent Laid-Open Publication No. 2019-11232) discloses high refractive index optical glass that contains a large amount of BaO and requires improved devitrification resistance.

[0005] The technical problem to be solved by the present invention is to provide an optical glass that is low in raw material cost and has excellent resistance to devitrification. [Means for solving the problem]

[0006] The technical solutions adopted by the present invention to solve the technical problems are as follows. Optical glass containing the following components by weight: SiO2: 1-12%, B2O3: 5-18%, La2O3: 40-60%, Y2O3: 4-20%, ZrO2: 1-12%, Nb2O5: 4-20%, TiO2: 4-18%.

[0007] The optical glass further contains the following components in weight percent: Gd2O3: 0-9%, and / or Ta2O5: 0-8%, and / or RO: 0-9%, and / or Rn2O: 0-6%, and / or WO3: 0-6%, and / or ZnO: 0-8%, and / or Al2O3: 0-5%, and / or Yb2O3: 0-10%, and / or GeO2: 0-5%, and / or a fining agent: 0-2%, where RO is one or more of MgO, CaO, SrO, and BaO, Rn2O is one or more of Li2O, Na2O, and K2O, and the fining agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0008] Optical glass containing the following components by weight: SiO2: 1-12%, B2O3: 5-18%, La2O3: 40-60%, Y2O3: 4-20%, ZrO2: 1-12%, Nb2O5: 4-20%, TiO2: 4-18%, Gd2O3: 0-9%, Ta2O5: 0-8%, RO: 0-9%, Rn2O: 0-6%, WO3: 0-6% , ZnO: 0-8%, Al2O3: 0-5%, Yb2O3: 0-10%, GeO2: 0-5%, fining agent: 0-2%, RO is one or more of MgO, CaO, SrO, BaO, Rn2O is one or more of Li2O, Na2O, K2O, and the fining agent is one or more of Sb2O3, SnO, SnO2, CeO2.

[0009] The optical glass further contains the following components in weight percent: La2O3+Y2O3+Gd2O3 is 46 to 70%, preferably La2O3+Y2O3+Gd2O3 is 50 to 68%, more preferably La2O3+Y2O3+Gd2O3 is 55 to 65%.

[0010] The optical glass further contains the following components in weight percent: SiO2+B2O3 is 8 to 28%, preferably SiO2+B2O3 is 10 to 25%, more preferably SiO2+B2O3 is 12 to 20%.

[0011] The optical glass further contains the following components in weight percent: (B2O3+TiO2) / (SiO2+ZnO) is 1.0 to 10.0, preferably (B2O3+TiO2) / (SiO2+ZnO) is 1.0 to 8.0, more preferably (B2O3+TiO2) / (SiO2+ZnO) is 1.5 to 7.0, and even more preferably (B2O3+TiO2) / (SiO2+ZnO) is 2.0 to 5.0.

[0012] Furthermore, the optical glass contains the following components in weight percent: (Ta2O5+Gd2O3) / Y2O3 is 1.0 or less, preferably (Ta2O5+Gd2O3) / Y2O3 is 0.6 or less, more preferably (Ta2O5+Gd2O3) / Y2O3 is 0.4 or less, and even more preferably (Ta2O5+Gd2O3) / Y2O3 is 0.1 or less.

[0013] The optical glass further contains the following components in weight percent: TiO2 / Y2O3 is 0.3 to 4.0, preferably TiO2 / Y2O3 is 0.5 to 3.0, more preferably TiO2 / Y2O3 is 0.6 to 2.0, and even more preferably TiO2 / Y2O3 is 0.75 to 1.5.

[0014] The optical glass further contains the following components in weight percent: Y2O3 / B2O3 is 0.4 to 3.0, preferably Y2O3 / B2O3 is 0.5 to 2.5, more preferably Y2O3 / B2O3 is 0.6 to 1.5, and even more preferably Y2O3 / B2O3 is 0.7 to 1.2.

[0015] The optical glass further contains the following components in weight percent: La2O3 / (TiO2+Nb2O5) is 1.2 to 6.0, preferably La2O3 / (TiO2+Nb2O5) is 1.5 to 5.0, more preferably La2O3 / (TiO2+Nb2O5) is 2.0 to 4.0, and even more preferably La2O3 / (TiO2+Nb2O5) is 2.5 to 3.5.

[0016] The optical glass further contains the following components in weight percent: TiO2 / (Nb2O5+WO3) is 0.3 to 3.0, preferably TiO2 / (Nb2O5+WO3) is 0.4 to 2.0, more preferably TiO2 / (Nb2O5+WO3) is 0.6 to 1.5, and even more preferably TiO2 / (Nb2O5+WO3) is 0.8 to 1.3.

[0017] Furthermore, the optical glass contains the following components in weight percent: ZnO / (SiO2+B2O3) is 0.5 or less, preferably ZnO / (SiO2+B2O3) is 0.3 or less, more preferably ZnO / (SiO2+B2O3) is 0.2 or less, and even more preferably ZnO / (SiO2+B2O3) is 0.1 or less.

[0018] The optical glass further contains the following components in weight percent: (Gd2O3+ZnO) / Y2O3 is 1.0 or less, preferably (Gd2O3+ZnO) / Y2O3 is 0.6 or less, more preferably (Gd2O3+ZnO) / Y2O3 is 0.3 or less, and even more preferably (Gd2O3+ZnO) / Y2O3 is 0.1 or less.

[0019] The optical glass further contains the following components in weight percent: WO3 / Y2O3 is 0.8 or less, preferably WO3 / Y2O3 is 0.6 or less, more preferably WO3 / Y2O3 is 0.02 to 0.5, and even more preferably WO3 / Y2O3 is 0.05 to 0.3.

[0020] The optical glass further contains the following components in weight percent: SiO2: 2 to 10%, preferably SiO2: 4 to 9%, and / or B2O3: 6 to 14%, preferably B2O3: 7 to 12%, and / or La2O3: 43 to 58%, preferably La2O3: 46 to 53%, and / or Y2O3: 5 to 15%, preferably Y2O3: 6 to 12%, and / or ZrO2: 3 to 10%. %, preferably ZrO2: 4 to 9%, and / or Nb2O5: 5 to 15%, preferably Nb2O5: 7 to 12%, and / or Ta2O5: 0 to 4%, preferably Ta2O5: 0 to 2%, and / or Gd2O3: 0 to 5%, preferably Gd2O3: 0 to 3%, more preferably Gd2O3: 0 to 1%, and / or TiO2: 5 to 13%, preferably TiO2: 6 to 12%, and and / or RO: 0-4%, preferably RO: 0-2%, and / or Rn2O: 0-4%, preferably Rn2O: 0-1%, and / or WO3: 0-4%, preferably WO3: 0.5-3%, and / or ZnO: 0-4%, preferably ZnO: 0-2%, and / or Al2O3: 0-3%, preferably Al2O3: 0-1%, and / or Yb2O3: 0-5%, preferably Yb2O3: 0-1%, and / or GeO2: 0-3%, preferably GeO2: 0-1%, and / or fining agent: 0-1%, preferably fining agent: 0-0.5%, RO is one or more of MgO, CaO, SrO, BaO, Rn2O is one or more of Li2O, Na2O, K2O, and the fining agent is one or more of Sb2O3, SnO, SnO2, CeO2.

[0021] The optical glass further contains the following components in weight percent: SiO2, B2O3, La2O3, Y2O3, ZrO2, Nb2O5, and TiO2, with a total content of 88% or more, preferably SiO2, B2O3, La2O3, Y2O3, ZrO2, Nb2O5, and TiO2 of 90% or more, more preferably SiO2, B2O3, La2O3, Y2O3, ZrO2, Nb2O5, and TiO2 of 92% or more, and even more preferably SiO2, B2O3, La2O3, Y2O3, ZrO2, Nb2O5, and TiO2 of 95% or more.

[0022] The optical glass further comprises components that are free of Ta2O5, and / or free of Yb2O3, and / or free of RO, and / or free of Rn2O, and / or free of ZnO, and / or free of Al2O3, and / or free of GeO2, wherein RO is one or more of MgO, CaO, SrO, and BaO, and Rn2O is one or more of Li2O, Na2O, and K2O.

[0023] Furthermore, the refractive index n of the optical glass d is 1.92 to 1.98, preferably 1.93 to 1.97, more preferably 1.94 to 1.96, and Abbe number v d is 29 to 36, preferably 30 to 35, and more preferably 31 to 34.

[0024] Furthermore, the density ρ of the optical glass is 5.10 g / cm 3 or less, preferably 5.00 g / cm 3 or less, more preferably 4.95 g / cm 3 and / or the thermal expansion coefficient α -30 / 70℃ is 85 x 10 -7 / K or less, preferably 80×10 -7 / K or less, preferably 75×10 -7 / K or less, more preferably 70×10 -7 / K or less, and / or water resistance stability D W is Class 2 or more, preferably Class 1, and / or acid resistance stability D A is class 2 or more, preferably class 1, and / or λ 70 is 425 nm or less, preferably λ 70 is 420 nm or less, more preferably λ 70 is 415 nm or less, and / or λ5 is 375 nm or less, preferably λ5 is 370 nm or less, more preferably λ5 is 365 nm or less, and / or weather resistance CR is Class 2 or more, preferably Class 1, and / or Knoop hardness H K is 650 x 10 7 Pa or more, preferably 660 x 10 7 Pa or more, preferably 670×10 7 Pa or more, more preferably 680 × 10 7Pa or more, and / or Young's modulus E is 11000 × 10 7 Pa~15000×10 7 Pa, preferably 11500 x 10 7 Pa~14500×10 7 Pa, more preferably 12000×10 7 Pa~14000×10 7 Pa, more preferably 12500×10 7 Pa~13500×10 7 Pa and / or foaming degree is A class or higher, preferably A0 class or higher, more preferably A 00 Grade and / or wear level F A is 80 to 130, preferably 90 to 120, and more preferably 95 to 115.

[0025] A glass preform manufactured from the above optical glass. An optical element manufactured from the above optical glass or the above glass preform. An optical instrument comprising the optical glass and / or the optical element. [Effects of the Invention]

[0026] The beneficial effects of the present invention are as follows: By rationally designing the components, the present invention makes it possible to obtain optical glass having excellent resistance to devitrification at lower raw material costs. DETAILED DESCRIPTION OF THE INVENTION

[0027] Hereinafter, embodiments of the optical glass according to the present invention will be described in detail, but the present invention is not limited to the embodiments described below, and can be practiced by making appropriate modifications within the scope of the object of the present invention. Furthermore, although some omissions may be made, the gist of the present invention is not limited by repetition of the description, and hereinafter the optical glass of the present invention may also be referred to simply as glass.

[0028] [Optical glass] The range of components of the optical glass of the present invention will be explained below. In this specification, the content and total content of each component will be expressed in weight percent (wt%) unless otherwise specified. That is, the content and total content of each component will be expressed as a weight percent relative to the total weight of the glass material converted into an oxide composition. "Converted to an oxide composition" here refers to the case where the total weight of the oxide material when the oxides, complex salts, hydroxides, etc. used as raw materials for the optical glass composition of the present invention are decomposed and converted into oxides during melting is taken as 100%.

[0029] Specifically, the numerical ranges set forth herein include upper and lower limits, and the terms "greater than or equal to" and "less than or equal to" include the endpoints, and all integers and fractions subsumed within the range, but are not limited to the specific values ​​set forth when the range is limited. References herein to "and / or" are inclusive, e.g., "A and / or B" means A only, B only, or both A and B.

[0030] <Required and optional ingredients> In the present invention, B2O3 is a network-forming component that improves the thermal stability and meltability of glass. In order to achieve these effects, 5% or more of B2O3 is added in the present invention, preferably a B2O3 content of 6% or more, and more preferably a B2O3 content of 7% or more. If the B2O3 content is too high, the refractive index of the glass decreases and the chemical stability deteriorates. Therefore, in the present invention, the upper limit of the B2O3 content is 18%, preferably 14%, and more preferably 12%.

[0031] SiO2 improves the chemical stability of glass, maintains a viscosity suitable for forming molten glass, and plays a role in reducing corrosion of refractories, but if its content is too high, it becomes difficult to melt the glass and is also disadvantageous in lowering the glass transition temperature. Therefore, in the present invention, the SiO2 content is 1 to 12%, preferably 2 to 10%, and more preferably 4 to 9%.

[0032] In some embodiments, by controlling the total content of SiO2 and B2O3 (SiO2 + B2O3) to within the range of 8 to 28%, the glass forming stability of the glass can be maintained, while the abrasion resistance and weather resistance of the glass can be optimized and a decrease in the devitrification resistance of the glass can be prevented. Therefore, SiO2 + B2O3 is preferably 8 to 28%, more preferably 10 to 25%, and even more preferably 12 to 20%.

[0033] La2O3 is an effective component for increasing the refractive index of glass and has a significant effect of improving the chemical stability and devitrification resistance of glass, but if its content is less than 40%, it is difficult to achieve the desired optical constants, and if its content exceeds 60%, the tendency of the glass to devitrify increases and thermal stability deteriorates. Therefore, the La2O3 content is 40 to 60%, preferably 43 to 58%, and more preferably 46 to 53%.

[0034] Y2O3 increases the refractive index and devitrification resistance of glass and can adjust the Young's modulus of glass. In the present invention, 4% or more of Y2O3 is added to achieve the above effects. If the content exceeds 20%, the chemical stability and weather resistance of the glass deteriorate. Therefore, in the present invention, the Y2O3 content is 4 to 20%, preferably 5 to 15%, and more preferably 6 to 12%.

[0035] In some embodiments, controlling the ratio of the Y2O3 content to the B2O3 content (Y2O3 / B2O3) within a range of 0.4 to 3.0 is advantageous for achieving an appropriate Young's modulus for the glass. Therefore, Y2O3 / B2O3 is preferably 0.4 to 3.0, and more preferably 0.5 to 2.5. Furthermore, controlling Y2O3 / B2O3 within a range of 0.6 to 1.5 is advantageous for further reducing the thermal expansion coefficient of the glass and optimizing the bubble content of the glass. Therefore, Y2O3 / B2O3 is more preferably 0.6 to 1.5, and even more preferably 0.7 to 1.2.

[0036] Although Gd2O3 can increase the refractive index and chemical stability of glass, if its content is too high, the devitrification resistance and abrasion resistance of the glass deteriorate, and the cost of the glass increases. Therefore, the Gd2O3 content is 0 to 9%, preferably 0 to 5%, more preferably 0 to 3%, and even more preferably 0 to 1%.

[0037] In some embodiments, by controlling the total content of La2O3, Y2O3, and Gd2O3 (La2O3+Y2O3+Gd2O3) to within 46 to 70%, the glass can easily achieve the desired refractive index and Abbe number, and the devitrification resistance and weather resistance of the glass can be optimized. Therefore, La2O3+Y2O3+Gd2O3 is preferably 46 to 70%, more preferably 50 to 68%, and even more preferably 55 to 65%.

[0038] Yb2O3 is also a component that imparts high refractive index and low dispersion to the glass, and if its content exceeds 10%, the crystallization resistance of the glass decreases. Therefore, the Yb2O3 content should be 0 to 10%, preferably 0 to 5%, more preferably 0 to 1%, and even more preferably no Yb2O3.

[0039] ZrO2 can increase the viscosity, hardness, refractive index, and chemical stability of optical glass and can also lower the thermal expansion coefficient of glass, but if the ZrO2 content is too high, the devitrification resistance of the glass will decrease, the melting difficulty will increase, the melting temperature will rise, inclusions will form inside the glass, and the light transmittance will decrease. Therefore, in the present invention, the ZrO2 content is 1 to 12%, preferably 3 to 10%, and more preferably 4 to 9%.

[0040] TiO2 is a high refractive index, high dispersion component, and its addition to glass can significantly improve the refractive index and dispersion of the glass. According to the inventors' research, adding an appropriate amount of TiO2 can increase the stability of the glass. However, if the TiO2 content is too high, the transmittance of the glass decreases significantly and the chemical stability of the glass also tends to deteriorate. Therefore, in the present invention, the TiO2 content is 4 to 18%, preferably 5 to 13%, and more preferably 6 to 12%.

[0041] In some embodiments, the abrasion resistance and weather resistance of the glass can be optimized by controlling the ratio of the TiO2 content to the Y2O3 content, TiO2 / Y2O3, within the range of 0.3 to 4.0. Therefore, TiO2 / Y2O3 is preferably 0.3 to 4.0, and more preferably 0.5 to 3.0. Furthermore, by controlling TiO2 / Y2O3 within the range of 0.6 to 2.0, the chemical stability and bubble content of the glass can be further improved. Therefore, TiO2 / Y2O3 is more preferably 0.6 to 2.0, and even more preferably 0.75 to 1.5.

[0042] Nb2O5 is a high-refractive, high-dispersion component that can increase the refractive index and devitrification resistance of glass and reduce the thermal expansion coefficient of glass. In order to achieve the above effects, the present invention adds 4% or more Nb2O5, with the lower limit of the Nb2O5 content being preferably 5%, more preferably 7%. If the Nb2O5 content exceeds 20%, the thermal stability and weather resistance of the glass will decrease and the light transmittance will decrease, so the upper limit of the Nb2O5 content in the present invention is 20%, preferably 15%, more preferably 12%.

[0043] In some embodiments, controlling the ratio of the La2O3 content to the total content of TiO2 and Nb2O5 (La2O3 / (TiO2+Nb2O5)) within the range of 1.2 to 6.0 is advantageous for increasing the Young's modulus of the glass and preventing a decrease in the glass's light transmittance. Therefore, La2O3 / (TiO2+Nb2O5) is preferably 1.2 to 6.0, and more preferably 1.5 to 5.0. Furthermore, controlling La2O3 / (TiO2+Nb2O5) within the range of 2.0 to 4.0 can further reduce the thermal expansion coefficient and density of the glass. Therefore, La2O3 / (TiO2+Nb2O5) is more preferably 2.0 to 4.0, and even more preferably 2.5 to 3.5.

[0044] Alkaline earth metal oxides RO (RO is one or more of MgO, CaO, SrO, and BaO) adjust the optical constants of the glass and can optimize the chemical stability of the glass, but a high RO content reduces the devitrification resistance of the glass. Therefore, the RO content is 0 to 9%, preferably 0 to 4%, and more preferably 0 to 2%. In some embodiments, it is even more preferable that the glass does not contain RO.

[0045] The alkaline metal oxide RnO (RnO is one or more of LiO, NaO, and KO) can lower the glass transition temperature, adjust the optical constants and high-temperature viscosity of the glass, and improve the meltability of the glass. However, if the RnO content is high, the devitrification resistance and chemical stability of the glass decrease. Therefore, in the present invention, the RnO content is 0 to 6%, preferably 0 to 4%, and more preferably 0 to 1%. In some embodiments, it is even more preferable that the glass does not contain RnO.

[0046] Although WO3 can increase the refractive index and mechanical strength of glass, if the WO3 content exceeds 6%, the thermal stability of the glass decreases, and the devitrification resistance decreases. Therefore, the WO3 content is 0 to 6%, preferably 0 to 4%, and more preferably 0.5 to 3%.

[0047] In some embodiments, controlling the ratio of the WO3 content to the Y2O3 content, WO3 / Y2O3, to 0.8 or less is advantageous for improving the chemical stability and crystallization resistance of the glass. Therefore, WO3 / Y2O3 is preferably 0.8 or less, and more preferably 0.6 or less. Furthermore, controlling WO3 / Y2O3 within the range of 0.02 to 0.5 can further optimize the hardness and bubble content of the glass. Therefore, WO3 / Y2O3 is more preferably 0.02 to 0.5, and even more preferably 0.05 to 0.3.

[0048] In some embodiments, controlling the ratio of TiO2 content to the total content of Nb2O5 and WO3 (Nb2O5 + WO3), TiO2 / (Nb2O5 + WO3), within the range of 0.3 to 3.0 can reduce the density of the glass while simultaneously preventing a decrease in the light transmittance of the glass. Therefore, TiO2 / (Nb2O5 + WO3) is preferably 0.3 to 3.0, and more preferably 0.4 to 2.0. Furthermore, controlling TiO2 / (Nb2O5 + WO3) within the range of 0.6 to 1.5 can further optimize the Young's modulus and weather resistance of the glass. Therefore, TiO2 / (Nb2O5 + WO3) is more preferably 0.6 to 1.5, and even more preferably 0.8 to 1.3.

[0049] ZnO adjusts the refractive index and dispersion of the glass, and can lower the high-temperature viscosity and transition temperature of the glass. If the ZnO content is too high, the glass becomes more difficult to mold and its crystallization resistance deteriorates. Therefore, the ZnO content is 0 to 8%, preferably 0 to 4%, and more preferably 0 to 2%. In some embodiments, it is even more preferable that no ZnO is contained.

[0050] In some embodiments, the ratio of ZnO to the total content of SiO and B O (SiO + B O), ZnO / (SiO + B O), can be controlled to 0.5 or less to improve the meltability of the glass, increase the degree of foaming, and optimize the abrasion resistance. Therefore, ZnO / (SiO + B O) is preferably 0.5 or less, more preferably 0.3 or less, even more preferably 0.2 or less, and even more preferably 0.1 or less.

[0051] In some embodiments, the ratio (B2O3+TiO2) / (SiO2+ZnO) of the total content of B2O3 and TiO2 (B2O3+TiO2) to the total content of SiO2 and ZnO (SiO2+ZnO) is controlled to 1.0 to 10.0, thereby improving the chemical stability of the glass and preventing a decrease in the light transmittance of the glass. Therefore, preferably, (B2O3+TiO2) / (SiO2+ZnO) is 1.0 to 10.0, and more preferably, (B2O3+TiO2) / (SiO2+ZnO) is 1.0 to 8.0. Furthermore, by controlling the ratio (B2O3+TiO2) / (SiO2+ZnO) to within the range of 1.5 to 7.0, the thermal expansion coefficient of the glass can be further reduced, thereby increasing the hardness of the glass. Therefore, more preferably, (B2O3+TiO2) / (SiO2+ZnO) is 1.5 to 7.0, and even more preferably, (B2O3+TiO2) / (SiO2+ZnO) is 2.0 to 5.0.

[0052] In some embodiments, the ratio of the total content of Gd2O3 and ZnO (Gd2O3 + ZnO) to the content of Y2O3 (Gd2O3 + ZnO) (Gd2O3 + ZnO) / Y2O3) is controlled to 1.0 or less, thereby reducing the thermal expansion coefficient of the glass and optimizing its wear resistance. Therefore, it is preferable that (Gd2O3 + ZnO) / Y2O3 is 1.0 or less, and more preferably, it is 0.6 or less. Furthermore, by controlling the ratio (Gd2O3 + ZnO) / Y2O3 to 0.3 or less, it is possible to easily obtain an appropriate Young's modulus for the glass and prevent a decrease in glass hardness. Therefore, it is more preferable that (Gd2O3 + ZnO) / Y2O3 is 0.3 or less, and even more preferably, it is 0.1 or less.

[0053] Ta2O5 can increase the refractive index and improve the devitrification resistance of glass, but if its content is too high, the thermal stability of the glass decreases and the density increases. Furthermore, Ta2O5 is very expensive compared to other components, and from the viewpoints of practicality and cost, it is necessary to minimize its use. Therefore, in the present invention, the Ta2O5 content is limited to 0 to 8%, preferably 0 to 4%, and more preferably 0 to 2%. In some embodiments, it is even more preferable that Ta2O5 is not included.

[0054] In some embodiments, controlling the ratio of the total content of Ta2O5 and Gd2O3 (Ta2O5 + Gd2O3) to the content of YO3 ((Ta2O5 + Gd2O3) / YO3) to 1.0 or less is advantageous for achieving an appropriate abrasion rate, optimizing the density and Young's modulus of the glass, and preventing a decrease in the chemical stability of the glass. Therefore, preferably, (Ta2O5 + Gd2O3) / YO3 is 1.0 or less, more preferably, 0.6 or less, even more preferably, 0.4 or less, and even more preferably, 0.1 or less.

[0055] Although Al2O3 can improve the chemical stability of glass, if its content exceeds 5%, the meltability and light transmittance of the glass deteriorate. Therefore, in the present invention, the Al2O3 content is 0 to 5%, preferably 0 to 3%, and more preferably 0 to 1%. In some embodiments, it is even more preferable that Al2O3 is not contained.

[0056] Although GeO2 can increase the refractive index and devitrification resistance, if its content is too high, the chemical stability of the glass decreases. Furthermore, GeO2 is very expensive compared to other components, and from the viewpoint of practicality and cost, its use amount must be reduced as much as possible. Therefore, the GeO2 content in the present invention is limited to 0 to 5%, preferably 0 to 3%, more preferably 0 to 1%, and even more preferably, GeO2 is not included.

[0057] In the present invention, the addition of 0-2% of one or more of Sb2O3, SnO, SnO2, and CeO2 as a fining agent can enhance the fining effect of the glass and improve the glass's cellularity. The fining agent content is preferably 0-1%, and more preferably 0-0.5%. Because the types and contents of the components of the optical glass of the present invention are rationally designed and the glass has an excellent cellularity, it is even more preferable in some embodiments to not contain a fining agent. If the Sb2O3 content exceeds 2%, the glass's fining tends to decrease, and its strong oxidizing effect accelerates corrosion of platinum or platinum alloy containers for molten glass and deterioration of molding dies. Therefore, the Sb2O3 content in the present invention is preferably 0-2%, more preferably 0-1%, even more preferably 0-0.5%, and even more preferably no Sb2O3. SnO and SnO2 can also be used as fining agents, but if their content exceeds 2%, the glass's tendency to discolor increases, or when the glass is heated, softened, and reshaped by press molding or the like, Sn acts as a starting point for crystal nucleation, leading to devitrification. Therefore, the SnO2 content in the present invention is preferably 0-2%, more preferably 0-1%, even more preferably 0-0.5%, and even more preferably no SnO2 is present. The SnO content is preferably 0-2%, more preferably 0-1%, even more preferably 0-0.5%, and even more preferably no SnO is present. The function and content of CeO2 are identical to those of SnO2, and its content is preferably 0-2%, more preferably 0-1%, even more preferably 0-0.5%, and even more preferably no CeO2 is present.

[0058] In some embodiments, in order to obtain a low coefficient of thermal expansion and density, a relatively high light transmittance and porosity, and an appropriate abrasion resistance and Young's modulus for the optical glass of the present invention, the total content of SiO2, B2O3, La2O3, Y2O3, ZrO2, Nb2O5, and TiO2 is preferably 88% or more, more preferably 90% or more, even more preferably 92% or more, and still more preferably 95% or more.

[0059] <Ingredients that should not be included> 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, even in small amounts, the glass is colored and specific wavelengths in the visible light region are absorbed, weakening the visible light transmission effect of the present invention. Therefore, it is preferable that optical glasses that require wavelength transmittance in the visible light region in particular do not actually contain these oxides. In recent years, there has been a trend toward restricting the use of oxides of Th, Cd, Tl, Os, Be, and Se as harmful chemicals, necessitating environmental protection efforts not only in the glass manufacturing process but also in the processing and disposal of finished products. Therefore, when environmental impact is a major concern, it is preferable to avoid these elements except for unavoidable contamination. This ensures that the optical glass does not contain substances that actually pollute the environment. Therefore, the optical glass of the present invention can be manufactured, processed, and disposed of without requiring special environmental measures. In consideration of the environment, the optical glass of the present invention preferably does not contain As2O3 and PbO.

[0060] The terms "not added," "not containing," and "0%" used herein mean that the component was not intentionally added as a raw material for the glass of the present invention. However, impurities or components not intentionally added as raw materials and / or equipment for producing the glass may exist in small or trace amounts in the final glass, and these are also within the scope of the patent of the present invention.

[0061] The properties of the optical glass of the present invention will be described below. <Refractive index and Abbe number> The refractive index of optical glass (n d ) and Abbe number (ν d ) has been tested in accordance with the method specified in "GB / T7962.1-2010". In some embodiments, the refractive index (n d ) has a lower limit of 1.92, preferably 1.93, and more preferably 1.94. In some embodiments, the refractive index (n d ) has an upper limit of 1.98, preferably 1.97, and more preferably 1.96. In some embodiments, the Abbe number (ν d ) has a lower limit of 29, preferably a lower limit of 30, and more preferably a lower limit of 31. In some embodiments, the Abbe number (ν d ) has an upper limit of 36, preferably 35, and more preferably 34.

[0062] <density> The density (ρ) of optical glass is tested according to the method described in "GB / T7962.20-2010". In some embodiments, the density (ρ) of the optical glass of the present invention is 5.10 g / cm 3 or less, preferably 5.00 g / cm 3 or less, more preferably 4.95 g / cm 3 The following is the result.

[0063] <Thermal expansion coefficient> The thermal expansion coefficient of optical glass (α -30 / 70℃ ) is measured at -30 to 70°C according to the method described in "GB / T7962.16-2010". In some embodiments, the thermal expansion coefficient (α -30 / 70℃ ) is 85 x 10 -7 / K or less, preferably 80×10 -7 / K or less, preferably 75×10 -7 / K or less, more preferably 70×10 -7 / K or less.

[0064] <Water resistance stability> Water resistance stability of optical glass (D W ) (powder method) is tested according to the method specified in "GB / T17129". In some embodiments, the water resistance stability (D W ) is class 2 or more, preferably class 1.

[0065] <Acid resistance stability> Acid resistance stability of optical glass (D A ) (powder method) is tested according to the method specified in "GB / T17129". In some embodiments, the acid resistance stability (D A ) is class 2 or more, preferably class 1.

[0066] <Coloring degree> The short-wave transmission spectrum characteristics of the glass of the present invention are determined by the coloring degree (λ 70 and λ5). 70 λ refers to the wavelength at which the glass transmittance reaches 70%. 70 The measurement is carried out using a glass with a thickness of 10±0.1 mm having two parallel, optically polished flat surfaces, and measuring the spectral transmittance in the wavelength range from 280 nm to 700 nm, and indicates the wavelength at which the transmittance is 70%. Spectral transmittance or transmittance is the wavelength at which the intensity I is measured perpendicular to the surface of the glass. in The light is incident on the glass and passes through it with an intensity of Iout When light of λ is emitted from a single plane, it is expressed as Iout / Iin, and it also includes the transmittance of the surface reflection loss at the surface of the glass. The higher the refractive index of the glass, the greater the surface reflection loss. Therefore, for high refractive index glass, λ 70 The smaller the value, the less coloring there is in the glass itself and the higher the light transmittance. In some embodiments, the λ 70 is 425 nm or less, preferably λ 70 is 420 nm or less, more preferably λ 70 is 415 nm or less. In some embodiments, the optical glass of the present invention has a λ5 of 375 nm or less, preferably a λ5 of 370 nm or less, and more preferably a λ5 of 365 nm or less.

[0067] <Weather resistance> The weather resistance (CR) test method for optical glass is as follows: the sample is placed in a test box in a saturated water vapor environment with a relative humidity of 90%, and the temperature is alternately circulated at 40-50°C every hour for 15 cycles. The weather resistance categories are classified based on the amount of turbidity change before and after leaving the sample, and the weather resistance categories are shown in Table 1.

[0068] [Table 1]

[0069] In some embodiments, the weather resistance (CR) of the optical glass of the present invention is Class 2 or higher, preferably Class 1.

[0070] <Knoop hardness> Knoop hardness of optical glass (H K ) has been tested in accordance with the test method specified in "GB / T7962.18-2010". In some embodiments, the Knoop hardness (H K ) is 650 x 10 7 Pa or more, preferably 660 x 10 7 Pa or more, preferably 670×107 Pa or more, more preferably 680 × 10 7 Pa or more.

[0071] <Young's modulus> Young's modulus (E) is calculated by measuring the longitudinal and shear wave velocities using ultrasound, according to the following formula:

[0072]

number

[0073] In some embodiments, the lower limit of the Young's modulus (E) of the optical glass of the present invention is 11000×10 7 Pa, preferably with a lower limit of 11500×10 7 Pa, and more preferably, the lower limit is 12000×10 7 Pa, and more preferably the lower limit is 12500×10 7 It is Pa. In some embodiments, the upper limit of the Young's modulus (E) of the optical glass of the present invention is 15000×10 7 Pa, preferably with an upper limit of 14500×10 7 Pa, and more preferably, the upper limit is 14000×10 7 Pa, and more preferably, the upper limit is 13500×10 7 It is Pa.

[0074] <Bubble content> The bubble content of optical glass is tested according to the method specified in "GB / T7962.8-2010". In some embodiments, the bubble content of the optical glass of the present invention is Class A or higher, preferably Class A0 or higher, more preferably Class A 00 It is a grade.

[0075] <Wear Level> Optical glass wear rate (F A ) is the ratio of the wear volume of the sample to the wear volume (volume) of a standard sample (H-K9 glass) under the exact same conditions, multiplied by 100, and the formula is as follows: F A =V / V0×100=(W / ρ) / (W0 / ρ0)×100 where V is the volumetric wear volume of the sample to be measured; V0 - volumetric wear volume of the standard sample; W - mass wear of the sample to be measured; W0 - quality wear volume of the standard sample; ρ - density of the sample to be measured; ρ0 - density of the standard sample.

[0076] In some embodiments, the abrasion rate (F A ) has a lower limit of 80, preferably 90, and more preferably 95. In some embodiments, the abrasion rate (F A ) The upper limit is 130, preferably 120, and more preferably 115.

[0077] [Optical glass manufacturing method] The method for producing the optical glass of the present invention is as follows: After mixing conventional raw materials, including but not limited to oxides, hydroxides, complex salts (carbonates, nitrates, sulfates, etc.), boric acid, etc., using conventional processes, the resulting furnace material is placed in a melting furnace (platinum or platinum alloy crucible) at 1200°C to 1450°C and melted. The mixture is then refined and homogenized to obtain a homogeneous molten glass free of bubbles and undissolved materials, which is then cast into a mold and annealed. Those skilled in the art will be able to select the appropriate raw materials, production methods, and process parameters according to actual needs.

[0078] [Glass preforms and optical elements] Glass preforms can be manufactured from optical glass prepared using press molding methods such as direct drop molding, polishing, or hot press molding. That is, molten optical glass can be made into a precision glass preform by direct precision drop molding, or a glass preform can be manufactured by mechanical processing such as grinding or polishing, or a preform blank for press molding can be prepared using optical glass, and this preform blank can be hot pressed and polished to produce a glass preform. It should be noted that the means for manufacturing optical preforms are not limited to the above means.

[0079] 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 blank from the optical glass of the present invention and use this blank to carry out hot press molding, precision press molding, or the like to produce optical elements such as lenses and prisms.

[0080] The optical preform and optical element of the present invention are both formed from the optical glass of the present invention. The optical 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.

[0081] Examples of lenses include various lenses 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, each having a spherical or aspherical lens surface.

[0082] [Optical equipment] Optical elements formed from the optical glass of the present invention can be used to manufacture optical equipment such as photographic devices, imaging devices, projection devices, display devices, in-vehicle devices, and monitoring devices. [Example]

[0083] <Optical Glass Examples> To further clearly illustrate the technical solutions of the present invention, the following non-limiting examples are provided. In the present examples, the above-described optical glass manufacturing method was used to obtain optical glasses having the components shown in Tables 2 to 4. The properties of each glass were measured using the test methods described in the present invention, and the results are shown in Tables 2 to 4.

[0084] [Table 2]

[0085] [Table 3]

[0086] [Table 4]

[0087] <Example of glass preform> The glasses obtained in Examples 1 to 24 of the optical glass are used to manufacture preforms of various lenses, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses, as well as prisms, using polishing means or press molding means such as reheat press molding and precision press molding.

[0088] <Optical element examples> These preforms obtained in the glass preform examples above are annealed to fine-tune the refractive index while reducing the stress inside the glass so that the optical properties, such as the refractive index, reach the desired values. Each preform is then ground and polished to produce various lenses and prisms, including concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses.Anti-reflection coatings can also be applied to the surfaces of the resulting optical elements.

[0089] <Optical equipment example> The optical elements manufactured according to the above optical element embodiments can be used in imaging devices, sensors, microscopes, medical technology, digital projection, communications, optical communication technology / information transmission, optics / illumination in the automotive field, photolithography technology, excimer lasers, wafers, computer chips and integrated circuits and electronic devices containing such circuits and chips, by using one or more optical elements according to optical design to form optical parts or components.

Claims

1. Optical glass containing the following components in weight percent: SiO 2 : 1-12%, B 2 O 3 : 5-18%, La 2 O 3 : 40-60%, Y 2 O 3 : 4-20%, ZrO 2 : 1-12%, Nb 2 O 5 : 4-20%, TiO 2 : 4 to 18%.

2. 10. The optical glass of claim 1 further comprising the following components in weight percent: Gd 2 O 3 : 0 to 9%, and / or Ta 2 O 5 : 0-8%, and / or RO: 0-9%, and / or Rn 2 O: 0-6% and / or WO 3 : 0-6%, and / or ZnO: 0-8%, and / or Al 2 O 3 : 0 to 5%, and / or Yb 2 O 3 : 0 to 10%, and / or GeO 2 : 0-5%, and / or fining agent: 0-2%, RO is one or more of MgO, CaO, SrO, BaO, Rn 2 O is Li 2 O, Na 2 OK 2 The fining agent is one or more of Sb 2 O 3 , SnO, SnO 2 , CeO 2 It is one or more of the following.

3. Optical glass containing the following components in weight percent: SiO 2 : 1-12%, B 2 O 3 : 5-18%, La 2 O 3 : 40-60%, Y 2 O 3 : 4-20%, ZrO 2 : 1-12%, Nb 2 O 5 : 4-20%, TiO 2 : 4-18%, Gd 2 O 3 : 0 to 9%, Ta 2 O 5 : 0-8%, RO: 0-9%, Rn 2 O: 0-6%, WO 3 : 0-6%, ZnO: 0-8%, Al 2 O 3 : 0-5%, Yb 2 O 3 : 0-10%, GeO 2 : 0-5%, fining agent: 0-2%, RO is one or more of MgO, CaO, SrO, BaO, Rn 2 O is Li 2 O, Na 2 OK 2 The fining agent is one or more of Sb 2 O 3 , SnO, SnO 2 , CeO 2 It is one or more of the following.

4. 4. The optical glass according to claim 1, comprising the following components in weight percent: 2 O 3 +Y 2 O 3 +Gd 2 O 3 is 46-70%, preferably La 2 O 3 +Y 2 O 3 +Gd 2 O 3 is 50 to 68%, more preferably La 2 O 3 +Y 2 O 3 +Gd 2 O 3 is 55-65%.

5. 4. The optical glass according to claim 1, comprising the following components in weight percent: SiO 2 +B 2 O 3 is 8 to 28%, preferably SiO 2 +B 2 O 3 is 10 to 25%, more preferably SiO 2 +B 2 O 3 is 12-20%.

6. 4. The optical glass according to claim 1, comprising the following components in weight percent: 2 O 3 +TiO 2 ) / (SiO 2 +ZnO) is 1.0 to 10.0, preferably (B 2 O 3 +TiO 2 ) / (SiO 2 +ZnO) is 1.0 to 8.0, more preferably (B 2 O 3 +TiO 2 ) / (SiO 2 +ZnO) is 1.5 to 7.0, more preferably (B 2 O 3 +TiO 2 ) / (SiO 2 +ZnO) is 2.0 to 5.

0.

7. 4. The optical glass according to claim 1, comprising the following components in weight percent: 2 O 5 +Gd 2 O 3 ) / Y 2 O 3 is 1.0 or less, preferably (Ta 2 O 5 +Gd 2 O 3 ) / Y 2 O 3 is 0.6 or less, more preferably (Ta 2 O 5 +Gd 2 O 3 ) / Y 2 O 3 is 0.4 or less, more preferably (Ta 2 O 5 +Gd 2 O 3 ) / Y 2 O 3 is less than or equal to 0.

1.

8. 4. The optical glass according to claim 1, comprising the following components in weight percent: TiO 2 / Y 2 O 3 is 0.3 to 4.0, preferably TiO 2 / Y 2 O 3 is 0.5 to 3.0, more preferably TiO 2 / Y 2 O 3 is 0.6 to 2.0, more preferably TiO 2 / Y 2 O 3 is between 0.75 and 1.

5.

9. 4. The optical glass according to claim 1, comprising the following components in weight percent: 2 O 3 / B 2 O 3 is 0.4 to 3.0, preferably Y 2 O 3 / B 2 O 3 is 0.5 to 2.5, more preferably Y 2 O 3 / B 2 O 3 is 0.6 to 1.5, and more preferably Y 2 O 3 / B 2 O 3 is between 0.7 and 1.

2.

10. 4. The optical glass according to claim 1, comprising the following components in weight percent: 2 O 3 / (TiO 2 +Nb 2 O 5 ) is 1.2 to 6.0, preferably La 2 O 3 / (TiO 2 +Nb 2 O 5 ) is 1.5 to 5.0, more preferably La 2 O 3 / (TiO 2 +Nb 2 O 5 ) is 2.0 to 4.0, more preferably La 2 O 3 / (TiO 2 +Nb 2 O 5 ) is 2.5 to 3.

5.

11. 4. The optical glass according to claim 1, comprising the following components in weight percent: TiO 2 / (Nb 2 O 5 +WO 3 ) is 0.3 to 3.0, preferably TiO 2 / (Nb 2 O 5 +WO 3 ) is 0.4 to 2.0, more preferably TiO 2 / (Nb 2 O 5 +WO 3 ) is 0.6 to 1.5, more preferably TiO 2 / (Nb 2 O 5 +WO 3 ) is 0.8 to 1.

3.

12. 4. The optical glass according to claim 1, comprising the following components in weight percent: ZnO / (SiO 2 +B 2 O 3 ) is 0.5 or less, preferably ZnO / (SiO 2 +B 2 O 3 ) is 0.3 or less, and more preferably ZnO / (SiO 2 +B 2 O 3 ) is 0.2 or less, and more preferably ZnO / (SiO 2 +B 2 O 3 ) is less than or equal to 0.

1.

13. 4. The optical glass according to claim 1, comprising the following components in weight percent: 2 O 3 +ZnO) / Y 2 O 3 is 1.0 or less, preferably (Gd 2 O 3 +ZnO) / Y 2 O 3 is 0.6 or less, more preferably (Gd 2 O 3 +ZnO) / Y 2 O 3 is 0.3 or less, more preferably (Gd 2 O 3 +ZnO) / Y 2 O 3 is less than or equal to 0.

1.

14. 4. The optical glass according to claim 1, comprising the following components in weight percent: WO 3 / Y 2 O 3 is 0.8 or less, preferably WO 3 / Y 2 O 3 is 0.6 or less, more preferably WO 3 / Y 2 O 3 is 0.02 to 0.5, more preferably WO 3 / Y 2 O 3 is between 0.05 and 0.

3.

15. 4. The optical glass according to claim 1, comprising the following components in weight percent: SiO 2 : 2 to 10%, preferably SiO 2 : 4-9%, and / or B 2 O 3 : 6 to 14%, preferably B 2 O 3 : 7-12%, and / or La 2 O 3 : 43 to 58%, preferably La 2 O 3 : 46-53%, and / or Y 2 O 3 : 5 to 15%, preferably Y 2 O 3 : 6 to 12%, and / or ZrO 2 : 3 to 10%, preferably ZrO 2 : 4 to 9%, and / or Nb 2 O 5 : 5 to 15%, preferably Nb 2 O 5 : 7 to 12%, and / or Ta 2 O 5 : 0 to 4%, preferably Ta 2 O 5 : 0-2% and / or Gd 2 O 3 : 0 to 5%, preferably Gd 2 O 3 : 0 to 3%, more preferably Gd 2 O 3 : 0 to 1%, and / or TiO 2 : 5 to 13%, preferably TiO 2 : 6 to 12%, and / or RO: 0 to 4%, preferably RO: 0 to 2%, and / or Rn 2 O: 0-4%, preferably Rn 2 O: 0-1% and / or WO 3 : 0 to 4%, preferably WO 3 : 0.5 to 3%, and / or ZnO: 0 to 4%, preferably ZnO: 0 to 2%, and / or Al 2 O 3 : 0 to 3%, preferably Al 2 O 3 : 0 to 1%, and / or Yb 2 O 3 : 0 to 5%, preferably Yb 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 1%, preferably fining agent: 0 to 0.5%, RO is one or more of MgO, CaO, SrO, and BaO, Rn 2 O is Li 2 O, Na 2 OK 2 The fining agent is one or more of Sb 2 O 3 , SnO, SnO 2 , CeO 2 It is one or more of the following.

16. 4. The optical glass according to claim 1, comprising the following components in % by weight: SiO 2 , B 2 O 3 , La 2 O 3 , Y 2 O 3 , ZrO 2 , Nb 2 O 5 , TiO 2 The total content is 88% or more, preferably SiO 2 , B 2 O 3 , La 2 O 3 , Y 2 O 3 , ZrO 2 , Nb 2 O 5 , TiO 2 The total content of is 90% or more, more preferably SiO 2 , B 2 O 3 , La 2 O 3 , Y 2 O 3 , ZrO 2 , Nb 2 O 5 , TiO 2 The total content of is 92% or more, and more preferably SiO 2 , B 2 O 3 , La 2 O 3 , Y 2 O 3 , ZrO 2 , Nb 2 O 5 , TiO 2 The total content is 95% or more.

17. The component is Ta 2 O 5 does not contain Yb 2 O 3 does not contain and / or does not contain RO and / or Rn 2 No O and / or no ZnO and / or Al 2 O 3 and / or GeO 2 does not contain Rn, RO is one or more of MgO, CaO, SrO, BaO 2 O is Li 2 O, Na 2 OK 2 The optical glass according to any one of claims 1 to 3, wherein O is one or more of O.

18. The optical glass according to any one of claims 1 to 3: the refractive index n d is 1.92 to 1.98, preferably 1.93 to 1.97, more preferably 1.94 to 1.96, and Abbe number v d is 29 to 36, preferably 30 to 35, more preferably 31 to 34.

19. The density ρ of the optical glass is 5.10 g / cm 3 or less, preferably 5.00 g / cm 3 or less, more preferably 4.95 g / cm 3 and / or the thermal expansion coefficient α -30 / 70℃ is 85 x 10 -7 / K or less, preferably 80×10 -7 / K or less, preferably 75×10 -7 / K or less, more preferably 70×10 -7 / K or less, and / or water resistance stability D W is Class 2 or more, preferably Class 1, and / or acid resistance stability D A is class 2 or more, preferably class 1, and / or λ 70 is 425 nm or less, preferably λ 70 is 420 nm or less, more preferably λ 70 is 415 nm or less, and / or λ 5 is 375 nm or less, preferably λ 5 is 370 nm or less, more preferably λ 5 is 365 nm or less, and / or weather resistance CR is class 2 or more, preferably class 1, and / or Knoop hardness H K is 650 x 10 7 Pa or more, preferably 660 x 10 7 Pa or more, preferably 670×10 7 Pa or more, more preferably 680 × 10 7 Pa or more, and / or Young's modulus E is 11000 × 10 7 Pa ~ 15000 x 10 7 Pa, preferably 11500 x 10 7 Pa~14500×10 7 Pa, more preferably 12000×10 7 Pa~14000×10 7 Pa, more preferably 12500×10 7 Pa~13500×10 7 Pa and / or foaming degree is A class or higher, preferably A 0 Grade or above, preferably A 00 Grade and / or wear level F A The optical glass according to any one of claims 1 to 3, wherein the refractive index is 80 to 130, preferably 90 to 120, and more preferably 95 to 115.

20. A glass preform made from the optical glass according to any one of claims 1 to 19.

21. An optical element manufactured using the optical glass according to any one of claims 1 to 19, or manufactured using the glass preform according to claim 20.

22. An optical instrument comprising the optical glass according to any one of claims 1 to 19 and / or the optical element according to claim 21.

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