Optical glass, glass preform, optical element, and optical instrument

Abstract

The present application provides an optical glass, which contains, in terms of weight percentage, SiO2: 1-12%; B2O3: 3-18%; La2O3: 45-65%; Y2O3: 1-13%; ZrO2: 1-13%; Nb2O5: 3-18%; TiO2: 5-20%. Through reasonable component design, the optical glass obtained by the present application has excellent chemical stability while having desired refractive index and Abbe number.

Description

Technical Field

[0001] This invention relates to an optical glass, and more particularly to an optical glass with a refractive index of 1.97 or higher and an Abbe number of 26 to 33, as well as glass preforms, optical elements and optical instruments made therefrom. Background Technology

[0002] In recent years, the digitization of optical instruments and the high-definition of images and videos have developed rapidly. The high-definition of images and videos is particularly prominent in optical instruments such as digital cameras, camcorders, and projectors. Simultaneously, the optical systems contained in these instruments are striving for weight reduction and miniaturization by reducing the number of optical components such as lenses or prisms. For the same radius of curvature, glass with a higher refractive index yields a larger imaging field of view, which is beneficial for reducing the number of optical components in optical instruments. With the trend towards miniaturization of optical instruments, the demand for high-refractive-index glass is becoming increasingly apparent. Optical glass is susceptible to corrosion from various liquids in the environment (such as acids, alkalis, and water) during processing or use. Therefore, the resistance of optical glass to these corrosive substances, i.e., its chemical stability, is crucial to the accuracy and lifespan of the instruments. Summary of the Invention

[0003] The technical problem to be solved by the present invention is to provide an optical glass with a refractive index of 1.97 or higher, an Abbe number of 26 to 33, and excellent chemical stability.

[0004] The technical solution adopted by this invention to solve the technical problem is:

[0005] Optical glass, the composition of which is expressed as a weight percentage, contains: SiO2: 1-12%; B2O3: 3-18%; La2O3: 45-65%; Y2O3: 1-13%; ZrO2: 1-13%; Nb2O5: 3-18%; TiO2: 5-20%.

[0006] Furthermore, the optical glass, whose composition is expressed as a weight percentage, also contains: Ta2O5: 0-8%; and / or Gd2O3: 0-8%; and / or RO: 0-8%; and / or Rn2O: 0-8%; and / or WO3: 0-6%; and / or ZnO: 0-8%; and / or Al2O3: 0-8%; and / or Yb2O3: 0-10%; and / or GeO2: 0-5%; and / or clarifying agent: 0-1%, 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 clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0007] Optical glass, the composition of which is expressed as a weight percentage, is composed of SiO2: 1-12%; B2O3: 3-18%; La2O3: 45-65%; Y2O3: 1-13%; ZrO2: 1-13%; Nb2O5: 3-18%; TiO2: 5-20%; Ta2O5: 0-8%; Gd2O3: 0-8%; RO: 0-8%; Rn2O: 0-8%; WO3: 0-6%; ZnO: 0-8%; Al2O3: 0-8%; Yb2O3: 0-10%; GeO2: 0-5%; and a clarifying agent: 0-1%. 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 clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0008] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein (Ta2O5+Gd2O3) / Y2O3 is 1.0 or less, preferably (Ta2O5+Gd2O3) / Y2O3 is 0.8 or less, more preferably (Ta2O5+Gd2O3) / Y2O3 is 0.5 or less, and even more preferably (Ta2O5+Gd2O3) / Y2O3 is 0.2 or less.

[0009] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: La2O3 / (RO+Nb2O5+Gd2O3) is 3.0 to 14.0, preferably 4.0 to 12.0, more preferably 5.0 to 9.0, and even more preferably 5.2 to 7.5, wherein RO is one or more of MgO, CaO, SrO, and BaO.

[0010] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein (Gd2O3+ZnO) / Y2O3 is 1.0 or less, preferably (Gd2O3+ZnO) / Y2O3 is 0.8 or less, more preferably (Gd2O3+ZnO) / Y2O3 is 0.5 or less, and even more preferably (Gd2O3+ZnO) / Y2O3 is 0.2 or less.

[0011] Furthermore, the optical glass, wherein the composition is expressed as a weight percentage, wherein (WO3+Gd2O3) / TiO2 is 2.0 or less, preferably (WO3+Gd2O3) / TiO2 is 1.5 or less, more preferably (WO3+Gd2O3) / TiO2 is 1.0 or less, and even more preferably (WO3+Gd2O3) / TiO2 is 0.5 or less.

[0012] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: La2O3 / (Y2O3+Al2O3) is 4.0 to 30.0, preferably 5.0 to 20.0, more preferably 7.0 to 15.0, and even more preferably 8.0 to 11.0.

[0013] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: La2O3 / (Ta2O5+Nb2O5) is 3.0 to 15.0, preferably 4.0 to 10.0, more preferably 5.0 to 8.0, and even more preferably 5.5 to 7.5.

[0014] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein (SiO2+B2O3) / Nb2O5 is 0.5 to 5.0, preferably (SiO2+B2O3) / Nb2O5 is 0.8 to 3.5, more preferably (SiO2+B2O3) / Nb2O5 is 1.0 to 2.5, and even more preferably (SiO2+B2O3) / Nb2O5 is 1.2 to 2.0.

[0015] Furthermore, the optical glass comprises, by weight percentage: SiO2: 2-10%, preferably SiO2: 3-8%; and / or B2O3: 5-15%, preferably B2O3: 6-12%; and / or La2O3: 47-60%, preferably La2O3: 50-56%; and / or Y2O3: 2-12%, preferably Y2O3: 4-10%; and / or ZrO2: 2-10%, preferably ZrO2: 3-9%; and / or Nb2O5: 5-15%, preferably Nb2O5: 6-12%; and / or Ta2O5: 0-5%, preferably Ta2O5: 0-1%; and / or Gd2O3: 0-4%, preferably Gd2O3: 0-2%; and / or TiO2: 8-18%, preferably TiO2: 11-17%; and / or RO The following components are used: 0-4%, preferably RO: 0-2%; and / or Rn2O: 0-4%, preferably Rn2O: 0-2%; and / or WO3: 0-4%, preferably WO3: 0-3%; and / or ZnO: 0-5%, preferably ZnO: 0-1%; and / or Al2O3: 0-5%, preferably Al2O3: 0-2%; and / or Yb2O3: 0-5%, preferably Yb2O3: 0-2%; and / or GeO2: 0-3%, preferably GeO2: 0-1%; and / or clarifying agent: 0-0.5%, preferably clarifying agent: 0-0.2%, 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 clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0016] Furthermore, the optical glass described herein does not contain Ta2O5; and / or ZnO; and / or Rn2O; and / or Gd2O3; and / or Yb2O3; and / or GeO2, wherein Rn2O is one or more of Li2O, Na2O, and K2O.

[0017] Furthermore, the refractive index n of the optical glass... d The Abbe number v is 1.97 or higher, preferably 1.98 or higher, more preferably 1.99 or higher, even more preferably 1.99 to 2.10, even more preferably 1.99 to 2.05, and still even more preferably 1.995 to 2.02. d The value is 26 to 33, preferably 27 to 32, and more preferably 28 to 31.

[0018] Furthermore, the coefficient of thermal expansion α of the optical glass is... 20 / 120℃ 95×10 -7 / K or less, preferably 90×10 -7 / K or less, preferably 85×10 -7Below / K, 80×10 is further preferred. -7 / K or below; and / or water resistance stability D W It is classified as Class 2 or above, preferably Class 1; and / or acid resistance stability D A The weather resistance (CR) is 2 or more, preferably 1; and / or the weather resistance (CR) is 2 or more, preferably 1; and / or the Knoop hardness (H) is... K 670×10 7 Pa or higher, preferably 680 × 10 Pa 7 Pa or higher, more preferably 690 × 10 Pa. 7 Pa or above; and / or Young's modulus E is 11000 × 10⁻⁶. 7 Pa or higher, preferably 12000 × 10 Pa 7 Pa or higher, more preferably 12500 × 10 Pa 7 Pa or higher, more preferably 12800×10 Pa 7 Pa or above; and / or λ 70 For wavelengths below 450nm, λ is preferred. 70 For wavelengths below 445nm, λ is preferred. 70 The wavelength is 440 nm or less; and / or λ5 is 390 nm or less, preferably 385 nm or less, more preferably 380 nm or less; and / or wear degree F A The value is 70-120, preferably 80-110, more preferably 85-105; and / or the bubble degree is A grade or above, preferably A0 grade or above, more preferably A. 00 class.

[0019] The glass preform is made of the aforementioned optical glass.

[0020] The optical element is made of the optical glass described above, or of the glass preform described above.

[0021] An optical instrument containing the aforementioned optical glass and / or containing the aforementioned optical elements.

[0022] The beneficial effects of this invention are: through reasonable component design, the optical glass obtained by this invention has excellent chemical stability while having the desired refractive index and Abbe number. Detailed Implementation

[0023] The embodiments of the optical glass of the present invention will now be described in detail. However, the present invention is not limited to the embodiments described below, and appropriate modifications can be made to implement it within the scope of the purpose of the present invention. Furthermore, regarding repeated descriptions, although there are appropriate omissions, this will not limit the spirit of the invention. In the following text, the optical glass of the present invention will sometimes be simply referred to as glass.

[0024] Optical Glass

[0025] The composition range of each component in the optical glass of the present invention will be described below. In the present invention, unless otherwise specified, the content of each component and the total content are all expressed as a weight percentage (wt%), that is, the weight percentage of the content of each component and the total content relative to the total amount of glass material converted into oxide composition. Here, "converted into oxide composition" means that when the oxides, complex salts, and hydroxides used as raw materials for the optical glass of the present invention decompose and transform into oxides upon melting, the total amount of such oxides is taken as 100%.

[0026] Unless otherwise specified in the specific context, the numerical ranges listed in this invention include upper and lower limits, and "above" and "below" include endpoint values ​​and all integers and fractions included in the range, but are not limited to the specific values ​​listed when the range is defined. The term "and / or" as used herein is inclusive; for example, "A and / or B" means only A, or only B, or both A and B.

[0027] <Essential and Optional Components>

[0028] B2O3 is a glass network-forming component that improves glass fusibility and devitrification resistance, and lowers glass transition temperature and density. This invention achieves these effects by containing 3% or more B2O3, preferably 5% or more, and more preferably 6% or more. However, if its content exceeds 18%, the stability of the glass decreases, and the refractive index decreases, making it difficult to achieve the high refractive index of this invention. Therefore, the maximum B2O3 content in this invention is 18%, preferably 15%, and more preferably 12%.

[0029] SiO2 is also a network-forming component, which can adjust the coefficient of thermal expansion of glass, improve its resistance to devitrification and chemical stability, and also improve its thermal stability and high-temperature viscosity. However, if its content exceeds 12%, the melting properties of the glass tend to deteriorate and the transition temperature increases. Therefore, the SiO2 content in this invention is 1-12%, preferably 2-10%, and more preferably 3-8%.

[0030] La2O3 is an effective component for improving the refractive index of glass, and it has a significant effect on improving the chemical stability and devitrification resistance of glass. If its content is less than 45%, it is difficult to achieve the required optical constant; if the content is higher than 65%, the glass's devitrification tendency increases and its thermal stability deteriorates. Therefore, the content of La2O3 is limited to 45-65%, preferably 47-60%, and more preferably 50-56%.

[0031] Y₂O₃ can improve the refractive index and devitrification resistance of glass, and adjust the Young's modulus of glass. This invention achieves the above effects by containing more than 1% Y₂O₃; if its content exceeds 13%, the chemical stability and weather resistance of the glass deteriorate. Therefore, the Y₂O₃ content in this invention is 1-13%, preferably 2-12%, and more preferably 4-10%.

[0032] Gd₂O₃ can improve the refractive index and chemical stability of glass, but if its content exceeds 8%, the glass's resistance to devitrification and abrasion becomes worse. Therefore, the content of Gd₂O₃ is 0–8%, preferably 0–4%, and more preferably 0–2%. In some embodiments, it is even more preferable that the glass does not contain Gd₂O₃.

[0033] Yb₂O₃ is also a component that imparts high refractive index and low dispersion to glass. If its content exceeds 8%, the glass's resistance to crystallization decreases. Therefore, the content of Yb₂O₃ is 0-10%, preferably 0-5%, more preferably 0-2%, and even more preferably does not contain Yb₂O₃.

[0034] ZrO2 can improve the viscosity, hardness, refractive index, and chemical stability of optical glass, and can also reduce the coefficient of thermal expansion of glass. However, when the ZrO2 content is too high, the glass's devitrification resistance decreases, melting difficulty increases, melting temperature rises, and inclusions appear inside the glass, leading to a decrease in light transmittance. Therefore, the ZrO2 content in this invention is 1-13%, preferably 2-10%, and more preferably 3-9%.

[0035] TiO2 is a high-refractive-index and high-dispersion component that can significantly improve the refractive index and dispersion of glass. The inventors have found that an appropriate amount of TiO2 can increase the stability of glass; however, excessive TiO2 content significantly reduces the transmittance of the glass and deteriorates its chemical stability. Therefore, the TiO2 content in this invention is 5–20%, preferably 8–18%, and more preferably 11–17%.

[0036] Nb₂O₅ is a high-refractive-index and high-dispersion component that can improve the refractive index and devitrification resistance of glass, and reduce the coefficient of thermal expansion of glass. In this invention, the above effects are achieved by containing more than 3% Nb₂O₅, preferably more than 5% Nb₂O₅, and more preferably more than 6% Nb₂O₅. If the Nb₂O₅ content exceeds 18%, the thermal stability and weather resistance of the glass decrease, and the light transmittance decreases. Therefore, the upper limit of the Nb₂O₅ content in this invention is 18%, preferably 15%, and more preferably 12%.

[0037] In some embodiments, controlling the ratio of the total SiO2 and B2O3 content (SiO2+B2O3) to the Nb2O5 content (SiO2+B2O3) / Nb2O5 within the range of 0.5 to 5.0 is beneficial for improving the hardness and weather resistance of the glass. Therefore, it is preferable that (SiO2+B2O3) / Nb2O5 is 0.5 to 5.0, more preferably (SiO2+B2O3) / Nb2O5 is 0.8 to 3.5. Furthermore, controlling (SiO2+B2O3) / Nb2O5 within the range of 1.0 to 2.5 can further optimize the abrasion resistance and bubble content of the glass. Therefore, it is even more preferable that (SiO2+B2O3) / Nb2O5 is 1.0 to 2.5, and even more preferably (SiO2+B2O3) / Nb2O5 is 1.2 to 2.0.

[0038] Alkaline earth metal oxides (RO, which is one or more of MgO, CaO, SrO, and BaO) can adjust the optical constants of glass and optimize its chemical stability. However, when the RO content is high, the glass's devitrification resistance decreases. Therefore, the RO content is limited to 0–8%, preferably 0–4%, and more preferably 0–2%.

[0039] In some embodiments, controlling the ratio of La2O3 content to the total content of RO, Nb2O5, and Gd2O3 (RO+Nb2O5+Gd2O3), La2O3 / (RO+Nb2O5+Gd2O3), within the range of 3.0 to 14.0 can improve the light transmittance and bubble content of the glass. Therefore, a La2O3 / (RO+Nb2O5+Gd2O3) ratio of 3.0 to 14.0 is preferred, and a La2O3 / (RO+Nb2O5+Gd2O3) ratio of 4.0 to 12.0 is more preferred. Furthermore, controlling the La2O3 / (RO+Nb2O5+Gd2O3) ratio within the range of 5.0 to 9.0 can further optimize the abrasion resistance of the glass and reduce its coefficient of thermal expansion. Therefore, the La2O3 / (RO+Nb2O5+Gd2O3) ratio is further preferred to be 5.0 to 9.0, and even more preferred to be 5.2 to 7.5.

[0040] Alkali metal oxides Rn₂O (Rn₂O is one or more of Li₂O, Na₂O, and K₂O) can lower the glass transition temperature, adjust the optical constants and high-temperature viscosity of the glass, and improve the glass's meltability. However, when its content is high, the glass's devitrification resistance and chemical stability decrease, and its refractive index decreases. Therefore, in this invention, the Rn₂O content is 0–8%, preferably 0–4%, and more preferably 0–2%. In some embodiments, it is further preferred that Rn₂O is not present.

[0041] WO3 can improve the refractive index and mechanical strength of glass. However, if the WO3 content exceeds 6%, the thermal stability and devitrification resistance of the glass decrease. Therefore, the WO3 content is 0–6%, preferably 0–4%, and more preferably 0–3%.

[0042] In some embodiments, controlling the ratio of the total content of WO3 and Gd2O3 (WO3+Gd2O3) to the content of TiO2 (WO3+Gd2O3) / TiO2 to 2.0 or less can improve the weather resistance and chemical stability of the glass and prevent a decrease in light transmittance. Therefore, it is preferable that (WO3+Gd2O3) / TiO2 is 2.0 or less, more preferably (WO3+Gd2O3) / TiO2 is 1.5 or less. Furthermore, controlling (WO3+Gd2O3) / TiO2 to 1.0 or less can further reduce the coefficient of thermal expansion of the glass. Therefore, it is even more preferable that (WO3+Gd2O3) / TiO2 is 1.0 or less, and even more preferably (WO3+Gd2O3) / TiO2 is 0.5 or less.

[0043] ZnO can adjust the refractive index and dispersion of glass, and reduce its high-temperature viscosity and transition temperature. However, if the ZnO content is too high, glass forming becomes more difficult, and its resistance to crystallization deteriorates. Therefore, the ZnO content is 0–8%, preferably 0–5%, and more preferably 0–1%. In some embodiments, it is further preferred that the glass does not contain ZnO.

[0044] In some embodiments, by controlling the ratio of the total content of Gd2O3 and ZnO (Gd2O3+ZnO) to the content of Y2O3 (Gd2O3+ZnO) / Y2O3 to below 1.0, the coefficient of thermal expansion of the glass can be reduced, and the abrasion resistance of the glass can be optimized. Therefore, it is preferable that (Gd2O3+ZnO) / Y2O3 is below 1.0, more preferably (Gd2O3+ZnO) / Y2O3 is below 0.8. Furthermore, controlling (Gd2O3+ZnO) / Y2O3 to below 0.5 makes it easier for the glass to obtain a suitable Young's modulus and prevents a decrease in glass hardness. Therefore, it is even more preferable that (Gd2O3+ZnO) / Y2O3 is below 0.5, and even more preferably (Gd2O3+ZnO) / Y2O3 is below 0.2.

[0045] Ta2O5 can improve the refractive index and enhance the devitrification resistance of glass, but if its content is too high, the thermal stability of the glass will decrease and the density will increase. On the other hand, compared with other components, Ta2O5 is very expensive. From the perspective of practicality and cost, its usage should be minimized. Therefore, the content of Ta2O5 in this invention is limited to 0-8%, preferably 0-5%, and more preferably 0-1%. In some embodiments, it is even more preferable that Ta2O5 is not present.

[0046] In some embodiments, controlling the ratio of the total content of Ta2O5 and Gd2O3 (Ta2O5+Gd2O3) to the content of Y2O3 (Ta2O5+Gd2O3) / Y2O3 to below 1.0 is beneficial for obtaining suitable abrasion resistance, optimizing glass density and Young's modulus, and preventing deterioration of glass chemical stability. Therefore, it is preferable that (Ta2O5+Gd2O3) / Y2O3 is below 1.0, more preferably (Ta2O5+Gd2O3) / Y2O3 is below 0.8, further preferably (Ta2O5+Gd2O3) / Y2O3 is below 0.5, and even more preferably (Ta2O5+Gd2O3) / Y2O3 is below 0.2.

[0047] In some embodiments, controlling the ratio of La2O3 content to the total content of Ta2O5 and Nb2O5 (Ta2O5+Nb2O5), La2O3 / (Ta2O5+Nb2O5), within the range of 3.0 to 15.0 can improve the bubble content and hardness of the glass. Therefore, a La2O3 / (Ta2O5+Nb2O5) ratio of 3.0 to 15.0 is preferred, and a La2O3 / (Ta2O5+Nb2O5) ratio of 4.0 to 10.0 is more preferred. Furthermore, controlling the La2O3 / (Ta2O5+Nb2O5) ratio within the range of 5.0 to 8.0 can further reduce the coefficient of thermal expansion of the glass and improve weather resistance. Therefore, a La2O3 / (Ta2O5+Nb2O5) ratio of 5.0 to 8.0 is further preferred, and a La2O3 / (Ta2O5+Nb2O5) ratio of 5.5 to 7.5 is even more preferred.

[0048] Al2O3 can improve the chemical stability of glass, but when its content exceeds 8%, the melt properties and light transmittance of the glass deteriorate. Therefore, in this invention, the Al2O3 content is 0-8%, preferably 0-5%, and more preferably 0-2%.

[0049] In some embodiments, controlling the ratio of La2O3 content to the total content of Y2O3 and Al2O3 (Y2O3+Al2O3), La2O3 / (Y2O3+Al2O3), within the range of 4.0 to 30.0 can improve the Young's modulus and bubble content of the glass and prevent a decrease in chemical stability. Therefore, it is preferable that La2O3 / (Y2O3+Al2O3) is 4.0 to 30.0, more preferably 5.0 to 20.0, even more preferably 7.0 to 15.0, and even more preferably 8.0 to 11.0.

[0050] GeO2 improves refractive index and devitrification resistance, but excessive content reduces the chemical stability of the glass. Furthermore, GeO2 is very expensive compared to other components, and its usage should be minimized from a practical and cost-effective perspective. Therefore, the GeO2 content in this invention is limited to 0-5%, preferably 0-3%, more preferably 0-1%, and even more preferably free of GeO2.

[0051] In this invention, one or more components selected from Sb₂O₃, SnO, SnO₂, and CeO₂ are used as clarifying agents, which can improve the clarification effect and bubble content of the glass. Preferably, the content of the clarifying agent is 0-0.5%, more preferably 0-0.2%. Because the optical glass of this invention has a reasonable design in terms of component types and content, resulting in excellent bubble content, it is further preferred in some embodiments to be free of clarifying agents. When the Sb₂O₃ content exceeds 1%, the glass tends to have reduced clarification performance. Simultaneously, its strong oxidizing effect promotes the corrosion of platinum or platinum alloy vessels used for molten glass and the deterioration of the forming mold. Therefore, in this invention, the Sb₂O₃ content is preferably 0-1%, more preferably 0-0.5%, further preferably 0-0.2%, and even more preferably free of Sb₂O₃. SnO and SnO2 can also be used as clarifying agents, but when their content exceeds 1%, the tendency for glass coloring increases. Alternatively, when the glass is heated, softened, and then molded, Sn can become the starting point for crystal nucleation, leading to a tendency for devitrification. Therefore, the SnO2 content of this invention is preferably 0-1%, more preferably 0-0.5%, further preferably 0-0.2%, and even more preferably free of SnO2. The SnO content is preferably 0-1%, more preferably 0-0.5%, further preferably 0-0.2%, and even more preferably free of SnO. The role and content ratio of CeO2 are the same as SnO2, and its content is preferably 0-1%, more preferably 0-0.5%, further preferably 0-0.2%, and even more preferably free of CeO2.

[0052] <Components that should not be present>

[0053] In the glass of this invention, even if oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo are contained in small amounts, either alone or in combination, the glass will be colored and absorb at specific wavelengths in the visible light region, thereby weakening the property of this invention to improve visible light transmittance. Therefore, it is preferable that the glass does not contain these oxides, especially for optical glass where transmittance in the visible light region is required.

[0054] Oxides of Th, Cd, Tl, Os, Be, and Se have been increasingly subject to controlled use in recent years due to their status as hazardous chemicals. Environmental protection measures are essential not only in glass manufacturing but also in processing and post-product disposal. Therefore, given the importance of environmental impact, it is preferable to avoid the presence of these substances, except where their contamination is unavoidable. As a result, the optical glass becomes virtually free of pollutants. Therefore, the optical glass of this invention can be manufactured, processed, and disposed of even without special environmental countermeasures.

[0055] To achieve environmental friendliness, the optical glass of the present invention preferably does not contain As2O3 and PbO.

[0056] The terms "not containing" and "0%" as used herein mean that the compound, molecule, or element was not intentionally added to the optical glass of this invention as a raw material; however, as raw materials and / or equipment for producing optical glass, there may be certain impurities or components that are not intentionally added, which may be present in small or trace amounts in the final optical glass, and such cases are also within the scope of protection of this patent.

[0057] The performance of the optical glass of the present invention will now be described.

[0058] <Refractive Index and Abbe Number>

[0059] The refractive index (n) of optical glass d ) and Abbe number (ν d Test according to the method specified in GB / T 7962.1—2010.

[0060] In some embodiments, the refractive index (n) of the optical glass of the present invention d The lower limit is 1.97, the preferred lower limit is 1.98, the more preferred lower limit is 1.99, and the even more preferred lower limit is 1.995.

[0061] In some embodiments, the refractive index (n) of the optical glass of the present invention d The upper limit of ) is 2.10, the preferred upper limit is 2.05, and the more preferred upper limit is 2.02.

[0062] In some embodiments, the Abbe number (ν) of the optical glass of the present invention d The lower limit is 26, the preferred lower limit is 27, and the more preferred lower limit is 28.

[0063] In some embodiments, the Abbe number (ν) of the optical glass of the present invention d The upper limit of ) is 33, the preferred upper limit is 32, and the more preferred upper limit is 31.

[0064] <Coefficient of thermal expansion>

[0065] The coefficient of thermal expansion of optical glass (α) 20 / 120℃ Data were tested at 20–120°C according to the method specified in GB / T7962.16-2010.

[0066] In some embodiments, the coefficient of thermal expansion (α) of the optical glass of the present invention is... 20 / 120℃ ) is 95×10 -7 / K or less, preferably 90×10 -7 / K or less, preferably 85×10 -7 Below / K, 80×10 is further preferred. -7 / K or below.

[0067] <Stability under water resistance>

[0068] Water resistance stability of optical glass (D) W (Powder method) Tested according to the method specified in GB / T 17129.

[0069] In some embodiments, the water resistance stability (D) of the optical glass of the present invention is... W There are two or more categories, with category 1 being preferred.

[0070] <Stability under acid conditions>

[0071] Acid resistance stability of optical glass (D) A (Powder method) Tested according to the method specified in GB / T 17129.

[0072] In some embodiments, the acid resistance stability (D) of the optical glass of the present invention is... A There are two or more categories, with category 1 being preferred.

[0073] <Weather resistance>

[0074] The weather resistance (CR) test method for optical glass is as follows: The sample is placed in a test chamber with a relative humidity of 90% saturated water vapor, and the temperature is alternately cyclical every 1 hour at 40–50°C, for 15 cycles. Weather resistance is classified according to the change in turbidity before and after the sample placement. The weather resistance classification is shown in Table 1.

[0075] Table 1.

[0076]

[0077] In some embodiments, the weather resistance (CR) of the optical glass of the present invention is Class 2 or above, preferably Class 1.

[0078] Knoop Hardness

[0079] Knoop hardness (H) of optical glassK The test shall be conducted in accordance with the test method specified in GB / T7962.18-2010.

[0080] In some embodiments, the Knoop hardness (H) of the optical glass of the present invention is... K ) is 670×10 7 Pa or higher, preferably 680 × 10 Pa 7 Pa or higher, more preferably 690 × 10 Pa. 7 Pa or above.

[0081] Young's Modulus

[0082] Young's modulus (E) is obtained by ultrasonic testing of its longitudinal and transverse wave velocities, and then calculated using the following formula.

[0083]

[0084] G = V S 2 ρ

[0085] In the formula: E is Young's modulus, Pa;

[0086] G is the shear modulus, Pa;

[0087] V T The transverse wave velocity is in m / s;

[0088] V S The longitudinal wave velocity is given in m / s.

[0089] ρ is the density of glass, in g / cm³ 3 .

[0090] In some embodiments, the Young's modulus (E) of the optical glass of the present invention is 11000 × 10⁻⁶. 7 Pa or higher, preferably 12000 × 10 Pa 7 Pa or higher, more preferably 12500 × 10 Pa 7 Pa or higher, more preferably 12800×10 Pa 7 Pa or above.

[0091] <wear level>

[0092] Abrasion resistance (F) of optical glass A The wear amount (volume) refers to the ratio of the wear amount of the test specimen to the wear amount (volume) of the standard specimen (H-K9 glass) under exactly the same conditions, multiplied by 100. The formula is as follows:

[0093] F A =V / V0×100=(W / ρ) / (W0 / ρ0)×100

[0094] Where: V—volume wear of the tested sample;

[0095] V0—Standard sample volume wear amount;

[0096] W—Mass wear of the tested sample;

[0097] W0—Standard sample mass wear amount;

[0098] ρ—Density of the sample being measured;

[0099] ρ0 — density of the standard sample.

[0100] In some embodiments, the abrasion degree (F) of the optical glass of the present invention A The lower limit is 70, the preferred lower limit is 80, and the more preferred lower limit is 85.

[0101] In some embodiments, the abrasion degree (F) of the optical glass of the present invention A The upper limit of ) is 120, the preferred upper limit is 110, and the more preferred upper limit is 105.

[0102] <Colorization>

[0103] The short-wavelength transmission spectral characteristics of the glass of this invention are expressed using colorimetry (λ). 70 And λ5) represent. λ 70 This refers to the wavelength corresponding to a glass transmittance of 70%. λ 70 The measurement was performed using a glass with a thickness of 10 ± 0.1 mm and two optically polished, parallel planes. The spectral transmittance was measured in the wavelength range from 280 nm to 700 nm, and wavelengths exhibiting 70% transmittance were recorded. Spectroscopic transmittance, or transmittance, is the value of transmittance when an intensity I is incident perpendicularly onto the aforementioned surface of the glass. in Light passes through the glass and exits from a plane with an intensity of I. out In the case of light, through I out / I in The value represents the transmittance, which also includes the surface reflection loss on the aforementioned surfaces of the glass. The higher the refractive index of the glass, the greater the surface reflection loss. Therefore, in high-refractive-index glasses, λ... 70 A low value means that the glass itself has very little coloration and high light transmittance.

[0104] In some embodiments, the λ of the optical glass of the present invention 70 For wavelengths below 450nm, λ is preferred. 70 For wavelengths below 445nm, λ is preferred. 70 It is below 440nm.

[0105] In some embodiments, the λ5 of the optical glass of the present invention is 390 nm or less, preferably 385 nm or less, and more preferably 380 nm or less.

[0106] <Effervescence>

[0107] The bubble content of optical glass shall be tested according to the method specified in GB / T7962.8-2010.

[0108] In some embodiments, the bubble degree of the optical glass of the present invention is grade A or above, preferably grade A0 or above, and more preferably grade A. 00 class.

[0109] [Manufacturing methods for optical glass]

[0110] The manufacturing method of the optical glass of this invention is as follows: The glass of this invention is produced using conventional raw materials and processes, including but not limited to using oxides, hydroxides, complex salts (such as carbonates, nitrates, sulfates, etc.), boric acid, etc. as raw materials. After the raw materials are prepared according to conventional methods, the prepared furnace charge is put into a melting furnace (such as a platinum or platinum alloy crucible) at 1200-1500°C for melting. After clarification and homogenization, a homogeneous molten glass without bubbles and undissolved substances is obtained. This molten glass is then cast in a mold and annealed. Those skilled in the art can appropriately select raw materials, process methods, and process parameters according to actual needs.

[0111] [Glass preforms and optical components]

[0112] Glass preforms can be manufactured from the produced optical glass using methods such as direct drop forming, grinding, or hot pressing. Specifically, glass preforms can be manufactured by directly and precisely drop-forming molten optical glass into precision glass preforms, or by machining such as grinding and polishing, or by hot pressing a preform made from optical glass for compression molding followed by grinding. It should be noted that the methods for preparing glass preforms are not limited to the methods described above.

[0113] As described above, the optical glass of the present invention is useful for various optical components and optical designs. It is particularly preferred to form a preform from the optical glass of the present invention, and to use the preform for hot pressing, precision stamping, etc., to manufacture optical components such as lenses and prisms.

[0114] Both the glass preform and the optical element of the present invention are formed from the optical glass described above. The glass preform of the present invention possesses the excellent properties of optical glass; the optical element of the present invention possesses the excellent properties of optical glass, and can provide various optical elements such as lenses and prisms with high optical value.

[0115] Examples of lenses include concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, plano-concave lenses, and so on, where the lens surface is spherical or aspherical.

[0116] [Optical Instruments]

[0117] The optical elements formed by the optical glass of this invention can be used to manufacture optical instruments such as photographic equipment, video equipment, projection equipment, display equipment, vehicle-mounted equipment, and monitoring equipment.

[0118] Example

[0119] <Example of Optical Glass>

[0120] To further illustrate and explain the technical solution of the present invention, the following non-limiting embodiments are provided.

[0121] In this embodiment, optical glass with the composition shown in Tables 2 to 4 was obtained using the optical glass manufacturing method described above. Furthermore, the properties of each glass were measured using the testing method described in this invention, and the measurement results are shown in Tables 2 to 4.

[0122] Table 2.

[0123]

[0124]

[0125] Table 3.

[0126]

[0127]

[0128] Table 4.

[0129]

[0130]

[0131] <Example of Glass Prefabricated Components>

[0132] The glass obtained from optical glass Examples 1 to 24# is used to manufacture preforms of various lenses and prisms, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses, by means of grinding, hot pressing, precision stamping, or other molding methods.

[0133] <Optical Component Examples>

[0134] Annealing these preforms obtained from the above glass preform examples reduces internal stress in the glass while fine-tuning the refractive index, so that optical properties such as the refractive index reach the desired values.

[0135] Next, the prefabricated parts are ground and polished to produce various lenses and prisms, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses. Anti-reflective coatings can also be applied to the surface of the resulting optical elements.

[0136] <Examples of Optical Instruments>

[0137] The optical elements obtained from the above-described optical element embodiments can be used, through optical design, to form optical components or optical assemblies by using one or more optical elements. These components can be used in, for example, imaging devices, sensors, microscopes, medical technology, digital projection, communications, optical communication technology / information transmission, optics / lighting in the automotive field, lithography technology, excimer lasers, wafers, computer chips, and integrated circuits and electronic devices that include such circuits and chips.

Claims

1. Optical glass, characterized in that, Its composition, expressed as a weight percentage, contains: SiO2: 3–12%; B2O3: 6–18%; La2O3: 50–65%; Y2O3: 1–13%; ZrO2: 1–5.43%; Nb2O5: 5–18%; TiO2: 5–20%, and does not contain Rn2O. The ratio of La2O3 / (Y2O3+Al2O3) is 8.0–11.0, La2O3 / (RO+Nb2O5+Gd2O3) is 4.0–7.5, and (SiO2+B2O3) / Nb2O5 is 0.5–1.

713. The Rn2O is one or more of Li2O, Na2O, and K2O. The refractive index n of the optical glass is... d The Abbe number v ranges from 1.99 to 2.0058. d The Knoop hardness ranges from 28.78 to 33. K 690×10 7 Above Pa, Young's modulus E is 13079 × 10⁻⁶. 7 Pa or above, wear degree F A It ranges from 80 to 98.

2. The optical glass according to claim 1, characterized in that, Its components, expressed as a weight percentage, also contain: Ta2O5: 0–8%; and / or Gd2O3: 0–8%; and / or RO: 0–8%; and / or WO3: 0–6%; and / or ZnO: 0–8%; and / or Al2O3: 0–8%; and / or Yb2O3: 0–10%; and / or GeO2: 0–5%; and / or clarifying agent: 0–1%, wherein the RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

3. Optical glass, characterized in that, Its composition, expressed as a weight percentage, is as follows: SiO2: 3–12%; B2O3: 6–18%; La2O3: 50–65%; Y2O3: 1–13%; ZrO2: 1–5.43%; Nb2O5: 5–18%; TiO2: 5–20%; Ta2O5: 0–8%; Gd2O3: 0–8%. RO: 0-8%; WO3: 0-6%; ZnO: 0–8%; Al2O3: 0–8%; Yb2O3: 0–10%; GeO2: 0–5%; Clarifying agent: 0–1% The composition is as follows: La₂O₃ / (Y₂O₃+Al₂O₃) is 8.0–11.0, La₂O₃ / (RO+Nb₂O₅+Gd₂O₃) is 4.0–7.5, (SiO₂+B₂O₃) / Nb₂O₅ is 0.5–1.713, wherein RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb₂O₃, SnO, SnO₂, and CeO₂. The refractive index n of the optical glass is... d The Abbe number v ranges from 1.99 to 2.0058. d The Knoop hardness ranges from 28.78 to 33. K 690×10 7 Above Pa, Young's modulus E is 13079 × 10⁻⁶. 7 Pa or above, wear degree F A It ranges from 80 to 98.

4. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which (Ta2O5+Gd2O3) / Y2O3 is less than 1.

0.

5. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which (Ta2O5+Gd2O3) / Y2O3 is less than 0.

8.

6. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which (Ta2O5+Gd2O3) / Y2O3 is less than 0.

5.

7. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which (Ta2O5+Gd2O3) / Y2O3 is less than 0.

2.

8. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: La2O3 / (RO+Nb2O5+Gd2O3) is 5.0 to 7.5, and the RO is one or more of MgO, CaO, SrO, and BaO.

9. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: La2O3 / (RO+Nb2O5+Gd2O3) is 5.2 to 7.5, and the RO is one or more of MgO, CaO, SrO, and BaO.

10. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which (Gd2O3+ZnO) / Y2O3 is less than 1.

0.

11. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which (Gd2O3+ZnO) / Y2O3 is less than 0.

8.

12. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which (Gd2O3+ZnO) / Y2O3 is less than 0.

5.

13. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which (Gd2O3+ZnO) / Y2O3 is less than 0.

2.

14. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, wherein (WO3+Gd2O3) / TiO2 is less than 2.

0.

15. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, wherein (WO3+Gd2O3) / TiO2 is less than 1.

5.

16. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, wherein (WO3+Gd2O3) / TiO2 is less than 1.

0.

17. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which (WO3+Gd2O3) / TiO2 is less than 0.

5.

18. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, of which: La2O3 / (Ta2O5+Nb2O5) is 3.0 to 15.

0.

19. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, of which: La2O3 / (Ta2O5+Nb2O5) is 4.0 to 10.

0.

20. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, of which: La2O3 / (Ta2O5+Nb2O5) is 5.0 to 8.

0.

21. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, of which: La2O3 / (Ta2O5+Nb2O5) is 5.5 to 7.

5.

22. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, of which (SiO2+B2O3) / Nb2O5 is 0.8 to 1.

713.

23. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, of which (SiO2+B2O3) / Nb2O5 is 1.0 to 1.

713.

24. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, of which (SiO2+B2O3) / Nb2O5 is 1.2 to 1.

713.

25. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: SiO2: 3-10%; and / or B2O3: 6-15%; and / or La2O3: 50-60%; and / or Y2O3: 2-12%; and / or ZrO2: 2-5.43%; and / or Nb2O5: 5-15%; and / or Ta2O5: 0-5%; and / or Gd2O3: 0-4%; and / or TiO2: 8-18%; and / or RO: 0-4%; and / or WO3: 0-4%; and / or ZnO: 0-5%; and / or Al2O3: 0-5%; and / or Yb2O3: 0-5%; and / or GeO2: 0-3%; and / or clarifying agent: 0-0.5%, wherein the RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

26. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: SiO2: 3-8%; and / or B2O3: 6-12%; and / or La2O3: 50-56%; and / or Y2O3: 4-10%; and / or ZrO2: 3-5.43%; and / or Nb2O5: 6-12%; and / or Ta2O5: 0-1%; and / or Gd2O3: 0-2%; and / or TiO2: 11-17%; and / or RO: 0-2%; and / or WO3: 0-3%; and / or ZnO: 0-1%; and / or Al2O3: 0-2%; and / or Yb2O3: 0-2%; and / or GeO2: 0-1%; and / or clarifying agent: 0-0.2%, wherein the RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

27. The optical glass according to any one of claims 1 to 3, characterized in that, Its components do not contain Ta2O5; and / or ZnO; and / or Gd2O3; and / or Yb2O3; and / or GeO2.

28. The optical glass according to any one of claims 1 to 3, characterized in that, The refractive index n of the optical glass d The Abbe number v ranges from 1.995 to 2.0058. d The range is 28.78 to 32.

29. The optical glass according to any one of claims 1 to 3, characterized in that, The Abbe number v of the optical glass d The range is 28.78 to 31.

30. The optical glass according to any one of claims 1 to 3, characterized in that, The coefficient of thermal expansion of the optical glass is α 20 / 120℃ 95×10 -7 / K or below; and / or water resistance stability D W Class 2 or above; and / or acid resistance stability D A Class 2 or above; and / or weather resistance CR is Class 2 or above; and / or λ 70 For wavelengths below 450nm; and / or λ5 below 390nm; and / or wear degree F A The value is 85-98; and / or the bubble degree is Grade A or above.

31. The optical glass according to any one of claims 1 to 3, characterized in that, The coefficient of thermal expansion of the optical glass is α 20 / 120℃ 90×10 -7 / K or below; and / or water resistance stability D W Class 1; and / or acid resistance stability D A Class 1; and / or weather resistance CR is Class 1; and / or λ 70 The wavelength is below 445nm; and / or λ5 is below 385nm; and / or the bubble degree is above A0.

32. The optical glass according to any one of claims 1 to 3, characterized in that, The coefficient of thermal expansion of the optical glass is α 20 / 120℃ 85×10 -7 / K below; and / or λ 70 The wavelength is below 440 nm; and / or λ5 is below 380 nm; and / or the bubble degree is A. 00 class.

33. The optical glass according to any one of claims 1 to 3, characterized in that, The coefficient of thermal expansion of the optical glass is α 20 / 120℃ 80×10 -7 / K below; and / or λ 70 The wavelength is below 440 nm; and / or λ5 is below 380 nm; and / or the bubble degree is A. 00 class.

34. A glass precast component, characterized in that, It is made of the optical glass described in any one of claims 1 to 33.

35. An optical element, characterized in that, It is made of optical glass as described in any one of claims 1 to 33, or of glass preform as described in claim 34.

36. An optical instrument, characterized in that, It contains the optical glass according to any one of claims 1 to 33, and / or contains the optical element according to claim 35.

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