High refractive index, low dispersion optical glass, glass preforms, optical elements and optical equipment

Abstract

To provide a high-refractive low-dispersion optical glass with superior chemical stability and devitrification resistance.SOLUTION: A high-refractive low-dispersion optical glass comprises following components, expressed in wt.%: SiO2: 3-20%, B2O3: 10-25%, La2O3: 35-65%, Y2O3: 5-30%, and ZrO2: 2-15%. The inventive optical glass features a rational component design, allowing for achievement of a desired refractive index and Abbe number, as well as superior chemical stability and devitrification resistance.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to optical glass, and more particularly to a high refractive index, low dispersion optical glass, and a glass preform, optical element, and optical instrument manufactured therefrom. [Background technology]

[0002] Lenses made from high-refractive-index, low-dispersion optical glass can be combined with lenses made from extra-low-dispersion glass to produce cemented lenses, which correct chromatic aberration and enable optical systems to be made more compact. Therefore, high-refractive-index, low-dispersion optical glass occupies a very important position as an optical element that constitutes imaging optical systems and projection optical systems such as projectors.

[0003] Optical glass with a refractive index of 1.78 to 1.86 and an Abbe number of 42 to 50 belongs to the category of high-refractive-index, low-dispersion optical glass, and has been widely used in recent years in fields such as automotive applications and surveillance security. Because optical glass comes into contact with large amounts of corrosive media during processing, poor acid resistance and water resistance will affect the imaging quality of the optical glass. Meanwhile, Patent Document 1 discloses optical glass containing 17 to 35% ZnO, having a refractive index of 1.80 to 1.84 and an Abbe number of 40.0 to 45.0, which is necessary to improve the devitrification resistance of the glass. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Chinese Patent Application Publication No. 101041552 Summary of the Invention [Problem to be solved by the invention]

[0005] The technical problem to be solved by the present invention is to provide a high refractive index, low dispersion optical glass having excellent chemical stability and 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:

[0007] High refractive index, low dispersion optical glass containing the following components by weight: SiO2: 3-20%, B2O3: 10-25%, La2O3: 35-65%, Y2O3: 5-30%, ZrO2: 2-15%.

[0008] The high refractive index, low dispersion optical glass further contains the following components in weight percent: Ta2O5: 0-10%, and / or Gd2O3: 0-10%, and / or Nb2O5: 0-5%, and / or TiO2: 0-5%, and / or RO: 0-8%, and / or Rn2O: 0-8%, and / or WO3: 0-5%, and / or ZnO: 0-8%, and / or Al2O3: 0-8%, and / or Yb2O3: 0-8%, and / or GeO2: 0-5%, and / or a fining agent: 0-2%, wherein the RO is one or more of MgO, CaO, SrO, and BaO; the Rn2O is one or more of Li2O, Na2O, and K2O; and the fining agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0009] The high refractive index, low dispersion optical glass further contains the following components in weight percent: SiO2: 3-20%, B2O3: 10-25%, La2O3: 35-65%, Y2O3: 5-30%, ZrO2: 2-15%, Ta2O5: 0-10%, Gd2O3: 0-10%, Nb2O5: 0-5%, TiO2: 0-5%, RO: 0-8%, Rn2O: 0-8%, WO3: 0- 5%, ZnO: 0-8%, Al2O3: 0-8%, Yb2O3: 0-8%, GeO2: 0-5%, fining agent: 0-2%, provided that the RO is one or more of MgO, CaO, SrO, and BaO, the Rn2O is one or more of Li2O, Na2O, and K2O, and the fining agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0010] Furthermore, the high refractive index, low dispersion optical glass contains the following components in weight percent: 45 to 75% La2O3 + Y2O3 + Gd2O3, preferably 50 to 75% La2O3 + Y2O3 + Gd2O3, more preferably 55 to 70% La2O3 + Y2O3 + Gd2O3, and even more preferably 60 to 70% La2O3 + Y2O3 + Gd2O3.

[0011] Furthermore, the high refractive index, low dispersion optical glass contains the following components in weight percent: (Gd2O3+ZnO) / Y2O3 is 1.0 or less, preferably (Gd2O3+ZnO) / Y2O3 is 0.8 or less, more preferably (Gd2O3+ZnO) / Y2O3 is 0.6 or less, and even more preferably (Gd2O3+ZnO) / Y2O3 is 0.4 or less.

[0012] The high refractive index, low dispersion optical glass further contains the following components in weight percent: (Gd2O3+Ta2O5) / Y2O3 is 1.5 or less, preferably (Gd2O3+Ta2O5) / Y2O3 is 0.05 to 1.0, more preferably (Gd2O3+Ta2O5) / Y2O3 is 0.1 to 0.8, and even more preferably (Gd2O3+Ta2O5) / Y2O3 is 0.1 to 0.6.

[0013] The high refractive index, low dispersion optical glass further contains the following components in weight percent: (B2O3+Gd2O3+Ta2O5) / SiO2 is 0.8 to 8.0, preferably (B2O3+Gd2O3+Ta2O5) / SiO2 is 1.0 to 6.0, more preferably (B2O3+Gd2O3+Ta2O5) / SiO2 is 1.5 to 5.0, and even more preferably (B2O3+Gd2O3+Ta2O5) / SiO2 is 1.5 to 3.5.

[0014] The high refractive index, low dispersion optical glass further contains the following components in weight percent: SiO2 / (B2O3+Nb2O5) is 0.15 to 1.5, preferably SiO2 / (B2O3+Nb2O5) is 0.2 to 1.0, more preferably SiO2 / (B2O3+Nb2O5) is 0.2 to 0.8, and even more preferably SiO2 / (B2O3+Nb2O5) is 0.25 to 0.65.

[0015] The high refractive index, low dispersion optical glass further contains the following components in weight percent: Y2O3 / (B2O3+Nb2O5) is 0.3 to 2.0, preferably Y2O3 / (B2O3+Nb2O5) is 0.4 to 1.8, more preferably Y2O3 / (B2O3+Nb2O5) is 0.5 to 1.5, and even more preferably Y2O3 / (B2O3+Nb2O5) is 0.6 to 1.2.

[0016] The high refractive index, low dispersion optical glass further contains the following components in weight percent: Ta2O5 / B2O3 is 0.85 or less, preferably Ta2O5 / B2O3 is 0.05 to 0.7, more preferably Ta2O5 / B2O3 is 0.1 to 0.6, and even more preferably Ta2O5 / B2O3 is 0.15 to 0.5.

[0017] Furthermore, the high refractive index, low dispersion optical glass contains the following components in weight percent: (Al2O3+Gd2O3) / ZrO2 is 2.5 or less, preferably (Al2O3+Gd2O3) / ZrO2 is 2.0 or less, more preferably (Al2O3+Gd2O3) / ZrO2 is 1.5 or less, and even more preferably (Al2O3+Gd2O3) / ZrO2 is 1.0 or less.

[0018] Furthermore, the high refractive index, low dispersion optical glass contains the following components in weight percent: (TiO2+WO3+Nb2O5) / Ta2O5 is 1.5 or less, preferably (TiO2+WO3+Nb2O5) / Ta2O5 is 1.0 or less, more preferably (TiO2+WO3+Nb2O5) / Ta2O5 is 0.8 or less, and even more preferably (TiO2+WO3+Nb2O5) / Ta2O5 is 0.5 or less.

[0019] The high refractive index, low dispersion optical glass further contains the following components in weight percent: SiO2: 4 to 15%, preferably SiO2: 5 to 12%, and / or B2O3: 12 to 22%, preferably B2O3: 14 to 20%, and / or La2O3: 40 to 60%, preferably La2O3: 42 to 55%, and / or Y2O3: 6 to 25%, preferably Y2O3: 8 to 22%, more preferably Y2O3: 11%. ~22%, and / or ZrO2: 3-12%, preferably ZrO2: 4-10%, and / or Nb2O5: 0-3%, preferably Nb2O5: 0-2%, and / or Ta2O5: 2-8%, preferably Ta2O5: 3-6%, and / or Gd2O3: 0-8%, preferably Gd2O3: 0-5%, more preferably Gd2O3: 0-3%, and / or TiO2: 0-3%, preferably TiO 2: 0-2%, and / or RO: 0-3%, preferably RO: 0-2%, and / or Rn2O: 0-3%, preferably Rn2O: 0-2%, and / or WO3: 0-3%, preferably WO3: 0-2%, and / or ZnO: 0-4%, preferably ZnO: 0-2%, and / or Al2O3: 0-4%, preferably Al2O3: 0-2%, and / or Yb2O3: 0-5%, preferably Yb Rn2O3: 0-3%, and / or GeO2: 0-3%, preferably GeO2: 0-1%, and / or fining agent: 0-1%, preferably fining agent: 0-0.5%, provided that the Rn2O is one or more of MgO, CaO, SrO, and BaO, the Rn2O is one or more of Li2O, Na2O, and K2O, and the fining agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0020] The high refractive index, low dispersion optical glass further comprises: said components being free of WO3, and / or free of TiO2, 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; provided that said RO is one or more of MgO, CaO, SrO, and BaO; and said Rn2O is one or more of Li2O, Na2O, and K2O.

[0021] Furthermore, the high refractive index, low dispersion optical glass contains the following components in weight percent: SiO2, B2O3, La2O3, Y2O3, ZrO2, and Ta2O5 with a total content of 86% or more, preferably SiO2, B2O3, La2O3, Y2O3, ZrO2, and Ta2O5 with a total content of 88% or more, more preferably SiO2, B2O3, La2O3, Y2O3, ZrO2, and Ta2O5 with a total content of 90% or more, and even more preferably SiO2, B2O3, La2O3, Y2O3, ZrO2, and Ta2O5 with a total content of 95% or more.

[0022] Furthermore, the refractive index n of the high refractive index, low dispersion optical glass d is 1.78 to 1.86, preferably 1.79 to 1.84, more preferably 1.80 to 1.83, and Abbe number v d is 42 to 50, preferably 44 to 48, and more preferably 45 to 47.5.

[0023] Furthermore, the density ρ of the high refractive index, low dispersion optical glass is 5.10 g / cm 3 or less, preferably 5.00 g / cm 3 or less, more preferably 4.90 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 λ 80 is 410 nm or less, preferably λ 80 is 400 nm or less, more preferably λ 80 is 395 nm or less, and / or λ5 is 325 nm or less, preferably λ5 is 315 nm or less, more preferably λ5 is 310 nm or less, and / or weather resistance CR is Class 2 or more, preferably Class 1, and / or Knoop hardness H K is 680 x 10 7 Pa or more, preferably 690 x 10 7 Pa or more, preferably 700×10 7Pa or more, more preferably 710 × 10 7 Pa or more, and / or Young's modulus E is 10500 × 10 7 Pa~14000×10 7 Pa, preferably 11000 x 10 7 Pa~13500×10 7 Pa, more preferably 11500×10 7 Pa~13000×10 7 Pa and / or wear rate F A and / or the foaming degree is class A or higher, preferably class A0 or higher, more preferably class A. 00 It is a grade.

[0024] A glass preform manufactured from the high refractive index, low dispersion optical glass.

[0025] An optical element manufactured from the high refractive index, low dispersion optical glass or the glass preform.

[0026] An optical instrument comprising the high refractive index, low dispersion optical glass and / or the optical element. [Effects of the Invention]

[0027] The beneficial effects of the present invention are as follows: Due to a rational component design, the optical glass obtained by the present invention has a desired refractive index and Abbe number, as well as excellent chemical stability and resistance to devitrification. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, embodiments of the high refractive index, low dispersion 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 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 high refractive index, low dispersion optical glass of the present invention may be referred to simply as optical glass or glass.

[0029] [High refractive index, low dispersion optical glass] The range of each constituent element (component) of the high refractive index, low dispersion optical glass of the present invention is explained below. In this specification, the content and total content of each component are expressed in weight percent (wt%) unless otherwise specified. That is, the content and total content of each component are expressed as weight percent relative to the total weight of the glass material converted into an oxide composition. Here, "converted into an oxide composition" 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%.

[0030] 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.

[0031] <Required and optional ingredients> SiO2 is the skeleton of optical glass and, as a glass network generator, maintains the chemical stability of the glass and enhances its resistance to devitrification. In the present invention, 3% or more of SiO2 is added to achieve the above effects, preferably with an SiO2 content of 4% or more, and more preferably with an SiO2 content of 5% or more. If the SiO2 content exceeds 20%, the meltability of the glass decreases and the transition temperature increases. Therefore, the upper limit of the SiO2 content is 20%, preferably 15%, and more preferably 12%.

[0032] B2O3 is a component that forms a glass network structure. In the present invention, adding 10% or more B2O3 maintains the stability of glass formation and improves the meltability and devitrification resistance of the glass. Therefore, the B2O3 content is preferably 12% or more, and more preferably 14% or more. However, if the B2O3 content exceeds 25%, the chemical stability of the glass decreases and the refractive index decreases. Therefore, in the present invention, the upper limit of the B2O3 content is 25%, preferably 22%, and more preferably 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 35%, it is difficult to achieve the desired optical constants, and if its content exceeds 65%, the tendency of the glass to devitrify increases and thermal stability decreases. Therefore, the La2O3 content is 35 to 65%, preferably 40 to 60%, and more preferably 42 to 55%.

[0034] Y2O3 maintains low dispersion while increasing the refractive index and devitrification resistance of the glass and adjusting the Young's modulus of the glass. To achieve these effects, the present invention adds 5% or more of Y2O3. However, if the Y2O3 content exceeds 30%, the chemical stability and weather resistance of the glass deteriorate. Therefore, the Y2O3 content in the present invention is 5 to 30%, preferably 6 to 25%, more preferably 8 to 22%, and even more preferably 11 to 22%.

[0035] Although Gd2O3 can increase the refractive index and chemical stability of glass, if its content exceeds 10%, the devitrification resistance of the glass decreases and the abrasion resistance increases. Therefore, the Gd2O3 content is 0 to 10%, preferably 0 to 8%, more preferably 0 to 5%, and even more preferably 0 to 3%.

[0036] In some embodiments, by controlling the total content of La2O3, Y2O3, and Gd2O3 (La2O3 + Y2O3 + Gd2O3) to within 45 to 75%, 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, preferably, La2O3 + Y2O3 + Gd2O3 is 45 to 75%, more preferably, La2O3 + Y2O3 + Gd2O3 is 50 to 75%, even more preferably, La2O3 + Y2O3 + Gd2O3 is 55 to 70%, and even more preferably, La2O3 + Y2O3 + Gd2O3 is 60 to 70%.

[0037] Yb2O3 is also a component that imparts high refractive index and low dispersion to the glass, and if its content exceeds 8%, the crystallization resistance of the glass decreases. Therefore, the Yb2O3 content should be 0 to 8%, preferably 0 to 5%, more preferably 0 to 3%, and even more preferably no Yb2O3.

[0038] ZrO2 can increase the viscosity, hardness, refractive index, and chemical stability of optical glass and can also reduce the thermal expansion coefficient of glass, but if the ZrO2 content is too high, the devitrification resistance of the glass decreases, the melting difficulty increases, the melting temperature rises, inclusions occur inside the glass, and the light transmittance decreases. Therefore, in the present invention, the ZrO2 content is 2 to 15%, preferably 3 to 12%, and more preferably 4 to 10%.

[0039] Although TiO2 can increase the refractive index of glass, too high a content significantly reduces the dispersion coefficient, increases the tendency for crystallization, and causes obvious coloration of the glass. Therefore, the TiO2 content is limited to 0-5%, preferably 0-3%, and more preferably 0-2%. In some embodiments, it is even more preferable to have no TiO2.

[0040] 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, 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, so from the perspective of practicality and cost, it is necessary to reduce its use as much as possible. Therefore, the Ta2O5 content in the present invention is limited to 0 to 10%, preferably 2 to 8%, and more preferably 3 to 6%.

[0041] In some embodiments, the chemical stability and devitrification resistance of the glass can be improved by controlling the ratio of the Ta2O5 content to the B2O3 content (Ta2O5 / B2O3) to 0.85 or less. Therefore, Ta2O5 / B2O3 is preferably 0.85 or less. Furthermore, the weather resistance and abrasion resistance of the glass can be further optimized by controlling Ta2O5 / B2O3 to a range of 0.05 to 0.7. Therefore, Ta2O5 / B2O3 is more preferably 0.05 to 0.7, even more preferably 0.1 to 0.6, and even more preferably 0.15 to 0.5.

[0042] In some embodiments, controlling the ratio of the total content of Gd2O3 and Ta2O5 (Gd2O3 + Ta2O5) to the content of Y2O3 (Gd2O3 + Ta2O5) / Y2O3 to 1.5 or less is advantageous for achieving an appropriate abrasion resistance of the glass and preventing a decrease in the chemical stability of the glass. Therefore, (Gd2O3 + Ta2O5) / Y2O3 is preferably 1.5 or less. Furthermore, controlling (Gd2O3 + Ta2O5) / Y2O3 to a value between 0.05 and 1.0 further optimizes the density and Young's modulus of the glass. Therefore, more preferably, (Gd2O3 + Ta2O5) / Y2O3 is between 0.05 and 1.0, even more preferably between 0.1 and 0.8, and even more preferably between 0.1 and 0.6.

[0043] In some embodiments, the ratio of the total content of B2O3, Gd2O3, and Ta2O5 (B2O3 + Gd2O3 + Ta2O5) to the content of SiO2 ((B2O3 + Gd2O3 + Ta2O5) / SiO2)) is controlled within a range of 0.8 to 8.0, thereby increasing the hardness of the glass and preventing a decrease in the weather resistance of the glass. Therefore, (B2O3 + Gd2O3 + Ta2O5) / SiO2 is preferably 0.8 to 8.0, and more preferably 1.0 to 6.0. Furthermore, by controlling (B2O3 + Gd2O3 + Ta2O5) / SiO2) within a range of 1.5 to 5.0, the cellular content and thermal expansion coefficient of the glass can be further optimized. Therefore, more preferably, (B2O3+Gd2O3+Ta2O5) / SiO2 is 1.5 to 5.0, and even more preferably, (B2O3+Gd2O3+Ta2O5) / SiO2 is 1.5 to 3.5.

[0044] Nb2O5 can increase the refractive index of the glass and improve the chemical stability and devitrification resistance of the glass. However, if the Nb2O5 content is too high, the dispersion of the glass increases, making it difficult to obtain glass with the desired optical constants, and also increasing the cost and density of the glass and reducing the short-wave transmittance in the visible light region. Therefore, the Nb2O5 content in the present invention is 5% or less, preferably 3% or less, and more preferably 2% or less.

[0045] In some embodiments, the hardness and light transmittance of the glass can be increased by controlling the ratio of the SiO2 content to the total content of B2O3 and Nb2O5 (B2O3 + Nb2O5), SiO2 / (B2O3 + Nb2O5), within a range of 0.15 to 1.5. Therefore, SiO2 / (B2O3 + Nb2O5) is preferably 0.15 to 1.5, and more preferably SiO2 / (B2O3 + Nb2O5) is 0.2 to 1.0. Furthermore, by controlling SiO2 / (B2O3 + Nb2O5) within a range of 0.2 to 0.8, the thermal expansion coefficient and Young's modulus of the glass can be further optimized. Therefore, SiO2 / (B2O3 + Nb2O5) is more preferably 0.2 to 0.8, and even more preferably SiO2 / (B2O3 + Nb2O5) is 0.2 to 0.65.

[0046] In some embodiments, the ratio of the Y2O3 content to the total content of B2O3 and Nb2O5 (B2O3 + Nb2O5), Y2O3 / (B2O3 + Nb2O5), can be controlled within a range of 0.3 to 2.0 to enhance the chemical stability of the glass, prevent an increase in glass density, and optimize the abrasion resistance of the glass. Therefore, Y2O3 / (B2O3 + Nb2O5) is preferably 0.3 to 2.0, more preferably 0.4 to 1.8, even more preferably 0.5 to 1.5, and even more preferably 0.6 to 1.2.

[0047] Alkaline earth metal oxides RO (RO is one or more of MgO, CaO, SrO, and BaO) can adjust the optical constants of glass and optimize the chemical stability of the glass, but a high RO content reduces the devitrification resistance of the glass. Therefore, the RO content is limited to 0 to 8%, preferably 0 to 3%, and more preferably 0 to 2%. In some embodiments, it is even more preferable that the glass does not contain RO.

[0048] Alkaline metal oxide RnO (RnO is one or more of LiO, NaO, and KO) lowers the glass transition temperature, adjusts the optical constants and high-temperature viscosity of glass, and can improve the meltability of glass. However, a high RnO content reduces the devitrification resistance and chemical stability of the glass. Therefore, in the present invention, the RnO content is 0 to 8%, preferably 0 to 3%, and more preferably 0 to 2%. In some embodiments, it is even more preferable that no RnO is contained.

[0049] Although WO3 can increase the refractive index and mechanical strength of glass, a WO3 content exceeding 5% reduces the thermal stability and devitrification resistance of the glass. Therefore, the upper limit of the WO3 content is 5%, preferably 3%, and more preferably 2%. In some embodiments, it is even more preferable to have no WO3.

[0050] In some embodiments, the ratio of the total content of TiO2, WO3, and Nb2O5 (TiO2 + WO3 + Nb2O5) to the content of Ta2O5 ((TiO2 + WO3 + Nb2O5)) / Ta2O5) is controlled to 1.5 or less, thereby reducing the coefficient of thermal expansion of the glass and preventing a decrease in light transmittance. Therefore, preferably, (TiO2 + WO3 + Nb2O5) / Ta2O5 is 1.5 or less, and more preferably, (TiO2 + WO3 + Nb2O5) / Ta2O5 is 1.0 or less. Furthermore, by controlling (TiO2 + WO3 + Nb2O5) / Ta2O5 to 0.8 or less, the degree of bubbles in the glass can be further optimized. Therefore, more preferably, (TiO2 + WO3 + Nb2O5) / Ta2O5 is 0.8 or less, and even more preferably, (TiO2 + WO3 + Nb2O5) / Ta2O5 is 0.5 or less.

[0051] 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 decreases. 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.

[0052] In some embodiments, the ratio of the total content of Gd2O3 and ZnO (Gd2O3 + ZnO) to the content of Y2O3 (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, (Gd2O3 + ZnO) / Y2O3 is preferably 1.0 or less, and more preferably 0.8 or less. Furthermore, controlling (Gd2O3 + ZnO) / Y2O3 to 0.6 or less makes it easier for the glass to achieve an appropriate Young's modulus and prevents a decrease in glass hardness. Therefore, (Gd2O3 + ZnO) / Y2O3 is more preferably 0.6 or less, and even more preferably 0.4 or less.

[0053] Although Al2O3 can improve the chemical stability of glass, if its content exceeds 8%, the meltability and light transmittance of the glass decrease. Therefore, in the present invention, the Al2O3 content is 0 to 8%, preferably 0 to 4%, and more preferably 0 to 2%. In some embodiments, it is even more preferable that Al2O3 is not contained.

[0054] In some embodiments, by controlling the ratio of the total content of Al2O3 and Gd2O3 (Al2O3 + Gd2O3) to the content of ZrO2 ((Al2O3 + Gd2O3) / ZrO2)) to 2.5 or less, the glass can easily achieve an appropriate abrasion resistance and Young's modulus and prevent a decrease in light transmittance. Therefore, preferably, (Al2O3 + Gd2O3) / ZrO2 is 2.5 or less, more preferably, (Al2O3 + Gd2O3) / ZrO2 is 2.0 or less, even more preferably, (Al2O3 + Gd2O3) / ZrO2 is 1.5 or less, and even more preferably, (Al2O3 + Gd2O3) / ZrO2 is 1.0 or less.

[0055] Although GeO2 can increase the refractive index and devitrification resistance of glass, if its content is too high, the chemical stability of the glass decreases. On the other hand, GeO2 is very expensive compared to other components, and from the viewpoint of practicality and cost, it is necessary to minimize its use. 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.

[0056] In the present invention, the addition of 0 to 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 bubble content of the glass. The fining agent content is preferably 0 to 1%, more preferably 0 to 0.5%. If the Sb2O3 content exceeds 2%, the fining ability of the glass tends to decrease, and its strong oxidizing effect accelerates corrosion of platinum or platinum alloy containers used for melting the glass and deterioration of molding dies. Therefore, the Sb2O3 content in the present invention is 0 to 2%, more preferably 0 to 1%, and even more preferably 0 to 0.5%. SnO and SnO2 can also be used as fining agents, but if their content exceeds 2%, the glass tends to become more colored. Furthermore, when the glass is heated, softened, and remolded by press molding, Sn tends to act as a starting point for crystal nucleation, resulting in devitrification. Therefore, the content of SnO2 in the present invention is preferably 0 to 2%, more preferably 0 to 1%, and even more preferably 0 to 0.5%, and the content of SnO is preferably 0 to 2%, more preferably 0 to 1%, and even more preferably 0 to 0.5%. The function and content of CeO2 are the same as those of SnO2, and its content is preferably 0 to 2%, more preferably 0 to 1%, and even more preferably 0 to 0.5%, and even more preferably does not contain CeO2.

[0057] In some embodiments, in order to obtain a low coefficient of thermal expansion and density, high hardness, and suitable wear resistance and Young's modulus for the optical glass of the present invention, the total content of SiO2, B2O3, La2O3, Y2O3, ZrO2, and Ta2O5 is preferably 86% or more, more preferably 88% or more, even more preferably 90% or more, and still more preferably 95% or more.

[0058] <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.

[0059] In recent years, there has been a trend toward restricting the use of oxides of Th, Cd, Tl, Os, Be, and Se as hazardous 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 the need for special environmental measures.

[0060] In consideration of the environment, the optical glass of the present invention preferably does not contain As2O3 and PbO.

[0061] 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 present invention.

[0062] The performance of the high refractive index, low dispersion 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 (ν d ) has been tested according to the method specified in GB / T 7962.1-2010.

[0064] In some embodiments, the refractive index (nd ) has a lower limit of 1.78, preferably 1.79, and more preferably 1.80.

[0065] In some embodiments, the refractive index (n d ) is 1.86, preferably 1.84, and more preferably 1.83.

[0066] In some embodiments, the Abbe number (ν d ) has a lower limit of 42, preferably a lower limit of 44, and more preferably a lower limit of 45.

[0067] In some embodiments, the Abbe number (ν d ) has an upper limit of 50, preferably 48, and more preferably 47.5.

[0068] <density> The density (ρ) of optical glass is tested according to the method described in GB / T7962.20-2010.

[0069] 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 4.90 g / cm 3 The following is the result.

[0070] <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.

[0071] 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.

[0072] <Water resistance stability> Water resistance stability of optical glass (D W ) (powder method) is tested according to the method specified in GB / T 17129.

[0073] In some embodiments, the water resistance stability (D W ) is class 2 or more, preferably class 1.

[0074] <Coloring degree> The short-wave transmission spectrum characteristics of the glass of the present invention are determined by the coloring degree (λ 80 and λ5). 80 λ refers to the wavelength at which the glass transmittance reaches 80%. 80 In the measurement, a glass with a thickness of 10±0.1 mm having two parallel, optically polished flat surfaces is used, and the spectral transmittance is measured in the wavelength range from 280 nm to 700 nm, and the wavelength at which the transmittance is 80% is shown. Spectral transmittance or transmittance is the intensity I in The light is incident on the glass and passes through it with an intensity of I out When light of λ is emitted from a single plane, it is expressed as Iout / Iin, and 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 80 The smaller the value, the less coloring there is in the glass itself and the higher the light transmittance.

[0075] In some embodiments, the λ 80 is 410 nm or less, preferably λ 80 is 400 nm or less, more preferably λ 80 is 395 nm or less.

[0076] In some embodiments, the λ5 of the optical glass of the present invention is 325 nm or less, preferably λ5 is 315 nm or less, and more preferably λ5 is 310 nm or less.

[0077] <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.

[0078] [Table 1]

[0079] In some embodiments, the weather resistance (CR) of the optical glass of the present invention is Class 2 or higher, preferably Class 1.

[0080] <Knoop hardness> Knoop hardness of optical glass (H K ) has been tested in accordance with the test method specified in GB / T 7962.18-2010.

[0081] In some embodiments, the Knoop hardness (H K ) is 680 x 10 7 Pa or more, preferably 690 x 10 7 Pa or more, preferably 700×10 7 Pa or more, more preferably 710 × 10 7 Pa or more.

[0082] <Young's modulus> Young's modulus (E) is calculated by measuring the longitudinal and shear wave velocities using ultrasound, according to the following formula:

number

[0083] In some embodiments, the lower limit of the Young's modulus (E) of the optical glass of the present invention is 10500×10 7 Pa, preferably with a lower limit of 11000×10 7 Pa, and more preferably, the lower limit is 11500×10 7 It is Pa.

[0084] In some embodiments, the upper limit of the Young's modulus (E) of the optical glass of the present invention is 14000×10 7 Pa, preferably with an upper limit of 13500×10 7 Pa, and more preferably, the upper limit is 13,000×10 7 It is Pa.

[0085] <Wear Level> Optical glass wear rate (F A ) is the ratio of the wear volume of the sample to the wear volume of a standard sample (H-K9 glass) under the 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.

[0086] In some embodiments, the abrasion rate (F A ) The lower limit is 100, preferably 105, more preferably 110, and even more preferably 115.

[0087] In some embodiments, the abrasion rate (F A) The upper limit is 150, preferably 145, more preferably 140, and even more preferably 135.

[0088] <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.

[0089] [Optical glass manufacturing method] The high refractive index, low dispersion optical glass of the present invention is manufactured by the following method: 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 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, manufacturing methods, and process parameters according to actual needs.

[0090] [Glass preforms and optical elements] Glass preforms can be manufactured from high-refractive-index, low-dispersion optical glass produced using direct drop molding or polishing, or press molding such as hot press molding. That is, molten optical glass can be produced into a precision glass preform by direct precision drop molding, or a glass preform can be produced by mechanical processing such as grinding or polishing, or a preform blank for press molding can be produced using optical glass, and this preform blank can be hot pressed and polished to produce a glass preform. It should be understood that the means for manufacturing optical preforms are not limited to the above means.

[0091] As described above, the high refractive index, low dispersion optical glass of the present invention is useful for a variety of optical elements and optical designs, and it is particularly preferred to form a preform from the high refractive index, low dispersion optical glass of the present invention and use this preform to produce optical elements such as lenses and prisms through reheat press molding, precision press molding, etc.

[0092] The glass preform and optical element of the present invention are both formed from the high-refractive-index, low-dispersion optical glass of the present invention. The glass preform of the present invention has the excellent properties of high-refractive-index, low-dispersion optical glass, and the optical element of the present invention has the excellent properties of optical glass, making it possible to provide various lenses, prisms, and other optical elements of high optical value.

[0093] 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.

[0094] [Optical equipment] Optical elements formed from the high refractive index, low dispersion optical glass of the present invention can be used to manufacture optical equipment such as photographic devices, imaging devices, projectors, display devices, in-vehicle devices, and monitoring devices. [Example]

[0095] <Examples of high refractive index, low dispersion optical glass> To further clearly illustrate the technical solutions of the present invention, the following non-limiting examples are provided.

[0096] In this example, high refractive index, low dispersion optical glasses having the components shown in Tables 2-1 to 4-2 were obtained using the above-described optical glass manufacturing method. The properties of each glass were measured using the test methods described in the present invention, and the results are shown in Tables 2-1 to 4-2.

[0097] [Table 2]

[0098] [Table 3]

[0099] [Table 4]

[0100] [Table 5]

[0101] [Table 6]

[0102] [Table 7]

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

[0104] <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.

[0105] 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.

[0106] <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. A high refractive index, low dispersion optical glass containing the following components in weight percent: SiO ２ : 3-20%, B ２ O ３ :10~25%, La ２ O ３ : 35-65%, Y ２ O ３ :5~30%, ZrO ２ : 2 to 15%, ZnO: 0 to 2.0%, but Ta ２ O ５ / B ２ O ３ is 0.037 to 0.85, The total content of SiO 2 , B 2 O 3 , La 2 O 3 , Y 2 O 3 , ZrO 2 and Ta 2 O 5 is 88% or more by weight, The refractive index n of the high refractive index, low dispersion optical glass ｄ is 1.80 to 1.83, and the Abbe number v ｄ is 45 to 47.

5.

2. 2. The high refractive index, low dispersion optical glass according to claim 1, further comprising the following components in weight percent: Ta ２ O ５ : 0.37 to 10%, and / or Gd ２ O ３ : 0 to 10%, and / or Nb ２ O ５ : 0 to 5%, and / or TiO ２ : 0 to 5%, and / or RO: 0 to 8%, and / or Rn ２ O: 0 to 8%, and / or WO ３ : 0 to 5%, and / or Al ２ O ３ : 0 to 8%, and / or Yb ２ O ３ : 0 to 8%, and / or GeO ２ : 0 to 5%, and / or clarifier: 0 to 2%, However, the RO is one or more of MgO, CaO, SrO and BaO, and the Rn ２ O is Li ２ O, Na ２ O and K ２ O, and the fining agent is Sb ２ O ３ , SnO, SnO ２ and CeO ２ It is one or more of the following.

3. A high refractive index, low dispersion optical glass containing the following components in weight percent: SiO ２ : 3-20%, B ２ O ３ :10~25%, La ２ O ３ : 35-65%, Y ２ O ３ :5~30%, ZrO ２ : 2 to 15%, Ta ２ O ５ :0.37~10%, Gd ２ O ３ : 0 to 10%, Nb ２ O ５ : 0 to 5%, TiO ２ : 0-5%, RO: 0-8%, Rn ２ O: 0-8%, WO ３ :0~5%, ZnO:0~2.0%, Al ２ O ３ : 0 to 8%, Yb ２ O ３ : 0 to 8%; GeO ２ : 0 to 5%, fining agent: 0 to 2%, except Ta ２ O ５ / B ２ O ３ is 0.037 to 0.85, The refractive index n of the high refractive index, low dispersion optical glass ｄ is 1.80 to 1.83, and the Abbe number v ｄ is 45 to 47.5, However, the RO is one or more of MgO, CaO, SrO and BaO, and the Rn ２ O is Li ２ O, Na ２ O and K ２ O, and the fining agent is Sb ２ O ３ , SnO, SnO ２ and CeO ２ It is one or more of the following.

4. 2. The high refractive index, low dispersion optical glass according to claim 1, comprising components, expressed in weight percent, that satisfy one or more of the following conditions 1) to 8): 1) La ２ O ３ +Y ２ O ３ +Gd ２ O ３ is 45-75%; 2) (Gd ２ O ３ +ZnO) / Y ２ O ３ is less than or equal to 1.0; 3) (Gd ２ O ３ +Ta ２ O ５ ) / Y ２ O ３ is 1.5 or less; 4) (B ２ O ３ +Gd ２ O ３ +Ta ２ O ５ ) / SiO ２ is 0.8 to 8.0; 5) SiO ２ / (B ２ O ３ +Nb ２ O ５ ) is 0.15 to 1.5; 6) Y ２ O ３ / (B ２ O ３ +Nb ２ O ５ ) is 0.3 to 2.0; 7) (Al ２ O ３ +Gd ２ O ３ ) / ZrO ２ is 2.5 or less; 8) (TiO ２ +WO ３ +Nb ２ O ５ ) / Ta ２ O ５ is 1.5 or less.

5. 2. The high refractive index, low dispersion optical glass according to claim 1, comprising components, expressed in weight percent, that satisfy one or more of the following conditions 1) to 9): 1) La ２ O ３ +Y ２ O ３ +Gd ２ O ３ is 50-75%; 2) (Gd ２ O ３ +ZnO) / Y ２ O ３ is 0.8 or less; 3) (Gd ２ O ３ +Ta ２ O ５ ) / Y ２ O ３ is 0.05 to 1.0; 4) (B ２ O ３ +Gd ２ O ３ +Ta ２ O ５ ) / SiO ２ is 1.0 to 6.0; 5) SiO ２ / (B ２ O ３ +Nb ２ O ５ ) is 0.2 to 1.0; 6) Y ２ O ３ / (B ２ O ３ +Nb ２ O ５ ) is 0.4 to 1.8; 7) Ta ２ O ５ / B ２ O ３ is 0.05 to 0.7; 8) (Al ２ O ３ +Gd ２ O ３ ) / ZrO ２ is 2.0 or less; 9) (TiO ２ +WO ３ +Nb ２ O ５ ) / Ta ２ O ５ is less than or equal to 1.

0.

6. 2. The high refractive index, low dispersion optical glass according to claim 1, comprising components, expressed in weight percent, that satisfy one or more of the following conditions 1) to 9): 1) La ２ O ３ +Y ２ O ３ +Gd ２ O ３ is 55-70%; 2) (Gd ２ O ３ +ZnO) / Y ２ O ３ is 0.6 or less; 3) (Gd ２ O ３ +Ta ２ O ５ ) / Y ２ O ３ is 0.1 to 0.8; 4) (B ２ O ３ +Gd ２ O ３ +Ta ２ O ５ ) / SiO ２ is 1.5 to 5.0; 5) SiO ２ / (B ２ O ３ +Nb ２ O ５ ) is 0.2 to 0.8; 6) Y ２ O ３ / (B ２ O ３ +Nb ２ O ５ ) is 0.5 to 1.5; 7) Ta ２ O ５ / B ２ O ３ is 0.1 to 0.6; 8) (Al ２ O ３ +Gd ２ O ３ ) / ZrO ２ is 1.5 or less; 9) (TiO ２ +WO ３ +Nb ２ O ５ ) / Ta ２ O ５ is 0.8 or less.

7. 2. The high refractive index, low dispersion optical glass according to claim 1, comprising components, expressed in weight percent, that satisfy one or more of the following conditions 1) to 9): 1) La ２ O ３ +Y ２ O ３ +Gd ２ O ３ is 60-70%; 2) (Gd ２ O ３ +ZnO) / Y ２ O ３ is 0.4 or less; 3) (Gd ２ O ３ +Ta ２ O ５ ) / Y ２ O ３ is 0.1 to 0.6; 4) (B ２ O ３ +Gd ２ O ３ +Ta ２ O ５ ) / SiO ２ is 1.5 to 3.5; 5) SiO ２ / (B ２ O ３ +Nb ２ O ５ ) is 0.25 to 0.65; 6) Y ２ O ３ / (B ２ O ３ +Nb ２ O ５ ) is 0.6 to 1.2; 7) Ta ２ O ５ / B ２ O ３ is 0.15 to 0.5; 8) (Al ２ O ３ +Gd ２ O ３ ) / ZrO ２ is less than or equal to 1.0; 9) (TiO ２ +WO ３ +Nb ２ O ５ ) / Ta ２ O ５ is 0.5 or less.

8. 2. The high refractive index, low dispersion optical glass according to claim 1, comprising the following components expressed in weight percent: SiO ２ : 4 to 15%, and / or B ２ O ３ : 12 to 22%, and / or La ２ O ３ : 40 to 60%, and / or Y ２ O ３ : 6 to 25%, and / or ZrO ２ : 3 to 12%, and / or Nb ２ O ５ : 0 to 3%, and / or Ta ２ O ５ : 2 to 8%, and / or Gd ２ O ３ : 0 to 8%, and / or TiO ２ : 0 to 3%, and / or RO: 0 to 3%, and / or Rn ２ O: 0 to 3%, and / or WO ３ : 0 to 3%, and / or Al ２ O ３ : 0 to 4%, and / or Yb ２ O ３ : 0 to 5%, and / or GeO ２ : 0 to 3%, and / or clarifier: 0 to 1%, However, the RO is one or more of MgO, CaO, SrO and BaO, and the Rn ２ O is Li ２ O, Na ２ O and K ２ O, and the fining agent is Sb ２ O ３ , SnO, SnO ２ and CeO ２ It is one or more of the following.

9. 2. The high refractive index, low dispersion optical glass according to claim 1, comprising the following components expressed in weight percent: SiO ２ : 5 to 12%, and / or B ２ O ３ : 14 to 20%, and / or La ２ O ３ : 42 to 55%, and / or Y ２ O ３ : 11 to 22%, and / or ZrO ２ : 4 to 10%, and / or Nb ２ O ５ : 0 to 2%, and / or Ta ２ O ５ : 3 to 6%, and / or Gd ２ O ３ : 0 to 3%, and / or TiO ２ : 0 to 2%, and / or RO: 0 to 2%, and / or Rn ２ O: 0 to 2%, and / or WO ３ : 0 to 2%, and / or Al ２ O ３ : 0 to 2%, and / or Yb ２ O ３ : 0 to 3%, and / or GeO ２ : 0 to 1%, and / or fining agent: 0 to 0.5%, However, the RO is one or more of MgO, CaO, SrO and BaO, and the Rn ２ O is Li ２ O, Na ２ O and K ２ O, and the fining agent is Sb ２ O ３ , SnO, SnO ２ and CeO ２ It is one or more of the following.

10. The component is WO ３ and / or TiO ２ does not contain RO and / or does not contain Rn ２ Does not contain O and / or does not contain ZnO and / or Al ２ O ３ and / or GeO ２ Does not include However, the RO is one or more of MgO, CaO, SrO and BaO, and the Rn ２ O is Li ２ O, Na ２ O and K ２ 2. The high refractive index, low dispersion optical glass according to claim 1, wherein the crystalline ...

11. In weight percent, SiO ２ , B ２ O ３ , La ２ O ３ , Y ２ O ３ , ZrO ２ and Ta ２ O ５ 2. The high refractive index, low dispersion optical glass according to claim 1, wherein the total content of is 95% or more.

12. The density ρ of the high refractive index, low dispersion optical glass is 5.10 g / cm ３ and / or a thermal expansion coefficient α －３０／７０℃ is 85 x 10 －７ / K or less, and / or water resistance stability D Ｗ is class 2 or more, and / or λ ８０ is 410 nm or less, and / or λ ５ is 325 nm or less, and / or the weather resistance CR is Class 2 or more, and / or the Knoop hardness H Ｋ is 680 x 10 ７ Pa or more, and / or Young's modulus E is 10500 × 10 ７ Pa~14000×10 ７ Pa and / or wear degree F Ａ 2. The high refractive index, low dispersion optical glass according to claim 1, wherein the refractive index is 100 to 150 and / or the bubble content is Class A or higher.

13. The density ρ of the high refractive index, low dispersion optical glass is 4.90 g / cm ３ and / or a thermal expansion coefficient α －３０／７０℃ is 70 x 10 －７ / K or less, and / or water resistance stability D Ｗ is class 1, and / or λ ８０ is 395 nm or less, and / or λ ５ is 310 nm or less, and / or weather resistance CR is Class 1, and / or Knoop hardness H Ｋ is 710 x 10 ７ Pa or more, and / or Young's modulus E is 11500 × 10 ７ Pa~13000×10 ７ Pa and / or wear degree F Ａ is 115 to 135, and / or the foaming degree is A ００ 2. The high refractive index, low dispersion optical glass according to claim 1,

14. A glass preform made from the high refractive index, low dispersion optical glass according to any one of claims 1 to 13.

15. An optical element manufactured using the high refractive index, low dispersion optical glass according to any one of claims 1 to 13.

16. An optical instrument comprising the high refractive index, low dispersion optical glass according to any one of claims 1 to 13.

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