Optical glass, optical element and optical instrument

Abstract

The invention provides optical glass, which comprises the following components in molar percentage: 25-40% of SiO2; 1 to 8 percent of B2O3; 1 to 8 percent of La2O3; 1 to 6 percent of BaO; 5 to 25 percent of CaO; 5 to 15 percent of Nb2O5; 8 to 20 percent of TiO2; the content of SiO2 and B2O3 is 27%-45%, and the content of Li2O is 1.5%-15%. The optical glass contains a proper amount of SiO2, alkali metal oxide and other components, so that the optical glass has excellent anti-devitrification performance; the optical glass contains high-refractive-index components such as Nb2O5 and TiO2, so that the optical glass has a relatively high refractive index; through reasonable component design, the glass has low relative partial dispersion.

Description

[0001] This application is a divisional application of the invention patent application with application number 202310923917.8, application date July 26, 2023, entitled "Optical Glass, Optical Components and Optical Instruments". Technical Field

[0002] This invention relates to an optical glass, and more particularly to an optical glass with a high refractive index and low relative partial dispersion that exhibits excellent resistance to crystallization. Background Technology

[0003] In long focal length, wide field-of-view, and high-precision optical systems, the second-order spectrum is a major factor affecting image quality. Correcting the second-order spectrum is a prominent and challenging issue in the design of long focal length optical systems. The correction of the second-order spectrum in an optical system largely depends on the choice of glass material; high refractive index and low relative partial dispersion (P0.05) are preferred. g,F When used in coupling lenses, glass with these properties can help eliminate secondary spectra, simplify and optimize optical systems, and improve image quality.

[0004] Secondary molding of optical glass has advantages such as low production cost, easy production, and ease of mass production, and is widely used in the manufacture of glass components. Secondary molding involves placing the glass material in a mold, heating it above its softening point, and then pressing it into a predetermined shape. Secondary molding of optical glass often requires heating the glass to 100-200°C above its transformation temperature. At this temperature, the glass already has a certain degree of fluidity. If the glass has poor resistance to crystallization, there is a risk of crystallization and scrapping during the secondary molding process. Chinese patent CN104583142A discloses an optical glass with low relative partial dispersion, whose composition contains 5.0% to 55.0% B2O3 and 15% to 60% rare earth oxides by mass. This optical glass has poor resistance to crystallization, posing a significant risk of crystallization during secondary molding. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an optical glass with high refractive index and low relative partial dispersion with excellent anti-crystallization performance.

[0006] The technical solution adopted by this invention to solve the technical problem is:

[0007] Optical glass, whose composition is expressed as molar percentage, contains: SiO2: 25-40%; B2O3: 1-8%; La2O3: 1-8%; BaO: 1-6%; CaO: 5-25%; Nb2O5: 5-15%; TiO2: 8-20%; Li2O: 1.5-15%.

[0008] Furthermore, the optical glass, expressed as a molar percentage, further contains: Al₂O₃: 0–5%; and / or Gd₂O₃: 0–8%; and / or Y₂O₃: 0–8%; and / or SrO: 0–15%; and / or MgO: 0–10%; and / or ZnO: 0–8%; and / or ZrO₂: 0–5%; and / or WO₃: 0–5%; and / or Bi₂O₃: 0–5%; and / or Ta₂O₅: 0–5%; and / or Na₂O: 0–10%; and / or K₂O: 0–10%; and / or Sb₂O₃: 0–1%.

[0009] Optical glass, its composition expressed as molar percentage, consists of SiO2: 25–40%; B2O3: 1–8%; La2O3: 1–8%; BaO: 1–6%; CaO: 5–25%; Nb2O5: 5–15%; TiO2: 8–20%; Li2O: 1.5–15%; Al2O3: 0–5%; Gd2O3: 0–8%; Y2O3: 0–8%; SrO: 0–15%; MgO: 0–10%; ZnO: 0–8%; ZrO2: 0–5%; WO3: 0–5%; Bi2O3: 0–5%; Ta2O5: 0–5%; Na2O: 0–10%; K2O: 0–10%; Sb2O3: 0–1%.

[0010] Furthermore, the optical glass comprises, in molar percentage, 27-45% SiO2 + B2O3, preferably 28-43%, more preferably 30-41%; and / or 25-44% SiO2 + ZrO2, preferably 27-42%, more preferably 29-40%; and / or 10-40% RO, preferably 12-38%, more preferably 15-35%; and / or 1-20% Re2O3, preferably Re... The content of 2O3 is 1.2-18%, more preferably 1.5-15% of Re2O3; and / or 2-14% of B2O3+La2O3, more preferably 3-13% of B2O3+La2O3, more preferably 4-12% of B2O3+La2O3; and / or 1-12% of B2O3+Al2O3, more preferably 2-11% of B2O3+Al2O3, more preferably 3-10% of B2O3+Al2O3, wherein RO is the total content of BaO, SrO, CaO and MgO, and Re2O3 is the total content of La2O3, Gd2O3 and Y2O3.

[0011] Furthermore, the optical glass, whose composition is expressed as a mole percentage, satisfies one or more of the following six conditions:

[0012] 1) The SiO2 / B2O3 ratio is 3.5 to 38.0, preferably 3.8 to 35.0, and more preferably 4.0 to 30.0;

[0013] 2) The ratio of (SiO2+ZrO2) / (B2O3+Li2O) is 1.8 to 15.0, preferably 1.9 to 12.0, and more preferably 2.0 to 10.0;

[0014] 3) The ratio of (Nb2O5+TiO2+WO3+Bi2O3+Ta2O5) / (SiO2+B2O3) is 0.3 to 1.8, preferably 0.4 to 1.6, and more preferably 0.5 to 1.4.

[0015] 4) The ratio of TiO2 / (Nb2O5+La2O3) is 0.35 to 3.2, preferably 0.4 to 3, and more preferably 0.5 to 2.8;

[0016] 5) The CaO / RO ratio is 0.25 to 0.95, preferably 0.3 to 0.8, and more preferably 0.4 to 0.7;

[0017] 6) The BaO / RO ratio is 0.03 to 0.5, preferably 0.04 to 0.4, and more preferably 0.05 to 0.3, wherein RO is the total content of BaO, SrO, CaO, and MgO.

[0018] Furthermore, the optical glass comprises, in molar percentage, SiO2: 27–38%, preferably SiO2: 29–36%; and / or B2O3: 2–7%, preferably B2O3: 3–6%; and / or La2O3: 2–7%, preferably La2O3: 3–6%; and / or BaO: 1.5–5%, preferably BaO: 2–4%; and / or CaO: 7–22%, preferably CaO: 9–20%; and / or Nb2O5: 6–14%, preferably Nb2O5: 7–13%; and / or TiO2: 9–19%, preferably TiO2: 10–18%; and / or Li2O: 2–13%, preferably Li2O: 3–11%; and / or Al2O3: 0–3%; and / or Gd2 O3: 0–6%, preferably Gd2O3: 0–4%; and / or Y2O3: 0–6%, preferably Y2O3: 0–4%; and / or SrO: 1–14%, preferably SrO: 2–12%; and / or MgO: 0–8%, preferably MgO: 0–5%; and / or ZnO: 0–6%, preferably ZnO: 0–4%; and / or ZrO2: 0–4%, preferably ZrO2: 0–3%; and / or WO3: 0–2%; and / or Bi2O3: 0–2%; and / or Ta2O5: 0–2%; and / or Na2O: 0–8%, preferably Na2O: 0–6%; and / or K2O: 0–8%, preferably K2O: 0–6%; and / or Sb2O3: 0–0.5%, preferably Sb2O3: 0–0.2%.

[0019] Furthermore, the optical glass described herein does not contain Al2O3; and / or does not contain WO3; and / or does not contain Bi2O3; and / or does not contain Ta2O5.

[0020] Furthermore, the refractive index (n) of the optical glass d The preferred refractive index (n) is 1.87–1.93. d The refractive index (n) is 1.88–1.92, and more preferably 1.88–1.92. d The Abbe number (ν) ranges from 1.89 to 1.91. d The optimal Abbe number is 24–30, with ν being the preferred value. d The Abbe number is 25–29, more preferably ν. d The range is 26 to 28.

[0021] Furthermore, the relative partial dispersion (P) of the optical glass g,F )≤0.6090, preferably relative partial dispersion (P) g,F )≤0.6085, more preferably relative partial dispersion (P g,F ) ≤0.6080; and / or internal transmittance (τ) 400 The internal transmittance (τ) is preferred to be above 0.68.400 The internal transmittance (τ) is 0.70 or higher, and more preferably internal transmittance (τ) is higher. 400 The following properties are also considered: a pH value of 0.72 or higher; and / or a weather resistance (CR) of Class 2 or higher, preferably Class 1; and / or an acid resistance of Class 2 or higher, preferably Class 1; and / or a density of 3.95 g / cm³. 3 The preferred density is 3.90 g / cm³. 3 The preferred density is 3.85 g / cm³. 3 the following.

[0022] The glass preform is made of the aforementioned optical glass.

[0023] The optical element is made of the aforementioned optical glass or the aforementioned glass preform.

[0024] An optical instrument containing the aforementioned optical glass and / or containing the aforementioned optical elements.

[0025] The beneficial effects of this invention are: by containing appropriate amounts of SiO2 and alkali metal oxides, the optical glass has excellent anti-crystallization properties; by containing high refractive index components such as Nb2O5 and TiO2, the optical glass has a high refractive index; and by rationally designing the composition, the glass has a low relative partial dispersion. Detailed Implementation

[0026] 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 present invention's objectives. Furthermore, while there are instances of appropriate omissions in the repeated descriptions, this does not limit the scope of the invention. In the following text, the optical glass of the present invention will sometimes be referred to simply as glass.

[0027] I. Optical Glass

[0028] The composition range of each component in the optical glass of the present invention will be described below. In this invention, unless otherwise specified, the content and total content of each component are expressed as molar percentages (mol%), that is, the molar percentage of the content and total content of each component relative to the total amount of glass material converted into oxide composition. Here, "converted into oxide composition" means that when the oxides, composite salts, and hydroxides used as raw materials for the optical glass of the present invention decompose and transform into oxides upon melting, the total molar amount of that oxide is taken as 100%.

[0029] 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.

[0030] <Essential and Optional Components>

[0031] SiO2 is a glass network generator that improves the glass's resistance to crystallization. If the SiO2 content is below 25%, it is difficult to achieve the aforementioned effect. Therefore, the lower limit for the SiO2 content is 25%, preferably 27%, and more preferably 29%. If the SiO2 content is above 40%, the glass becomes difficult to melt, and it is difficult to obtain the refractive index desired by this invention. Therefore, the upper limit for the SiO2 content is 40%, preferably 38%, and more preferably 36%.

[0032] B2O3 can reduce the difficulty of glass processing and lower the high-temperature viscosity and transition temperature of the glass. Most importantly, in this invention, a small amount of B2O3 can significantly improve the glass's resistance to crystallization. However, in this invention, excessive B2O3 content leads to a decrease in the chemical stability of the glass, especially its acid resistance. Therefore, the B2O3 content in this invention is 1–8%, preferably 2–7%, and more preferably 3–6%.

[0033] Both SiO2 and B2O3 function as a glass network in this invention. An excessively high total content (SiO2 + B2O3) makes it difficult to achieve high refractive properties, while an excessively low content leads to poor resistance to crystallization. Therefore, a preferred content of SiO2 + B2O3 is 27–45%, more preferably 28–43%, and even more preferably 30–41%.

[0034] In some embodiments of the present invention, controlling the SiO2 / B2O3 ratio (SiO2 / B2O3) within the range of 3.5 to 38.0 is beneficial for the glass to obtain excellent chemical stability and resistance to crystallization. Therefore, a SiO2 / B2O3 ratio of 3.5 to 38.0 is preferred, a SiO2 / B2O3 ratio of 3.8 to 35.0 is more preferred, and a SiO2 / B2O3 ratio of 4.0 to 30.0 is even more preferred.

[0035] Al2O3 can improve the weather resistance of glass, but it also increases the glass melting temperature and high-temperature viscosity, making production more difficult. When the Al2O3 content exceeds 5%, the glass tends to exhibit poorer melting properties and reduced devitrification resistance. Therefore, in this invention, the Al2O3 content is 0-5%, preferably 0-3%, and more preferably no Al2O3.

[0036] In some embodiments of the present invention, by controlling the total content of B2O3 and Al2O3 (B2O3+Al2O3) within the range of 1% to 12%, it is beneficial to maintain the relative partial dispersion of the glass within the design range. Therefore, it is preferable that the content of B2O3+Al2O3 is 1% to 12%, more preferably 2% to 11%, and even more preferably 3% to 10%.

[0037] La2O3 is a high-refractive-index, low-dispersion component that can significantly reduce the relative partial dispersion of glass. However, excessively high La2O3 content leads to decreased acid resistance in the glass. Therefore, the La2O3 content in this invention is 1–8%, preferably 2–7%, and more preferably 3–6%.

[0038] B₂O₃ and La₂O₃ can cause significant corrosion to glass furnaces during production. Limiting the total amount of B₂O₃ and La₂O₃ can extend the lifespan of glass furnaces, reduce the difficulty of glass production, and improve glass quality. Meanwhile, the inventors have found that B₂O₃ and La₂O₃ have a significant impact on the acid resistance of the glass of this invention; excessively high content can negatively affect the acid resistance. Therefore, the preferred content of B₂O₃ + La₂O₃ is 2–14%, more preferably 3–13%, and even more preferably 4–12%.

[0039] Gd₂O₃ is a high-refractive-index, low-dispersion component that can reduce the relative partial dispersion of glass. However, the high cost of raw materials limits the use of Gd₂O₃ in glass. Therefore, the content of Gd₂O₃ is 0–8%, preferably 0–6%, and more preferably 0–4%.

[0040] Y₂O₃ can improve the melting properties of glass and enhance its weather resistance, but excessive Y₂O₃ content can reduce the glass's resistance to crystallization. Therefore, the Y₂O₃ content is 0–8%, preferably 0–6%, and more preferably 0–4%.

[0041] La2O3, Gd2O3, and Y2O3 in glass can increase the refractive index and reduce relative partial dispersion. However, if their content is too low, it will be difficult to achieve the high refractive index and low dispersion optical properties desired by this invention. If their content is too high, the glass's resistance to crystallization will deteriorate. Therefore, in this invention, the total content of La2O3, Gd2O3, and Y2O3 (Re2O3) is preferably 1-20%, more preferably 1.2-18%, and even more preferably 1.5-15%.

[0042] BaO is a low-cost and readily available raw material that can effectively improve the refractive index of glass. However, BaO is detrimental to reducing the density of glass, and excessive BaO content also reduces the weather resistance of the glass. Therefore, the BaO content is limited to 1-6%, preferably 1.5-5%, and more preferably 2-4%.

[0043] An appropriate amount of SrO can improve the weather resistance and reduce the density of glass, but because SrO is expensive, excessive content will increase the cost of glass. Therefore, the content of SrO is limited to 0-15%, preferably 1-14%, and more preferably 2-12%.

[0044] CaO can improve the hardness, mechanical strength, and weather resistance of glass. More importantly, compared to BaO and SrO, CaO is more beneficial for reducing the density of glass. Furthermore, CaO is advantageous for controlling and adjusting optical constants during the production process. However, excessive CaO content leads to difficulties in glass melting, and a calcium-rich hard shell easily forms in the melting pool during production. Therefore, the CaO content is limited to 5-25%, preferably 7-22%, and more preferably 9-20%.

[0045] MgO helps improve the weather resistance of glass, but when the content is high, the refractive index of the glass is difficult to meet design requirements, the anti-crystallization performance and stability of the glass decrease, and the cost of the glass increases rapidly. Therefore, the MgO content is limited to 0-10%, preferably 0-8%, and more preferably 0-5%.

[0046] BaO, SrO, CaO, and MgO are all alkaline earth metal oxides. In this invention, in order to obtain excellent anti-crystallization properties and mechanical strength, the total content of alkaline earth metal oxides BaO, SrO, CaO, and MgO is preferably 10-40%, more preferably 12-38%, and even more preferably 15-35%.

[0047] This invention reduces glass density and improves glass crystallization stability by controlling the relative content of each component of alkaline earth metal oxides. In some embodiments, by controlling the CaO / RO ratio (CaO / RO) within the range of 0.25 to 0.95, glass density can be reduced, acid resistance improved, and anti-crystallization properties enhanced. Therefore, a CaO / RO ratio of 0.25 to 0.95 is preferred, more preferably 0.3 to 0.8, and even more preferably 0.4 to 0.7. In some embodiments, controlling the BaO / RO ratio (BaO / RO) within the range of 0.03 to 0.5 is beneficial for improving glass anti-crystallization properties. Therefore, a BaO / RO ratio of 0.03 to 0.5 is preferred, more preferably 0.04 to 0.4, and even more preferably 0.05 to 0.3.

[0048] ZnO can improve the acid resistance and weather resistance of glass, and lower the glass transition temperature. However, when its content is too high, it will increase the corrosion of platinum utensils during the melting process and reduce the service life of the furnace. Therefore, the ZnO content in the glass of this invention is 0-8%, preferably 0-6%, and more preferably 0-4%.

[0049] ZrO2 improves the weather resistance and enhances the anti-crystallization properties of glass. Simultaneously, ZrO2 can significantly reduce the relative partial dispersion of glass. However, ZrO2 has low solubility in this glass system; excessive content can lead to it escaping from the glass system and forming crystal nuclei, thus deteriorating the glass's anti-crystallization performance. Therefore, the ZrO2 content in this invention is 0–5%, preferably 0–4%, and more preferably 0–3%.

[0050] Both SiO2 and ZrO2 can improve the acid resistance of glass, and they are also two components that are relatively difficult to melt in this invention. Through extensive experimental research, the inventors have found that in some embodiments, controlling the total content of SiO2 and ZrO2 (SiO2+ZrO2) within the range of 25-44% allows the glass to achieve both excellent acid resistance and good production performance. Therefore, a SiO2+ZrO2 content of 25-44% is preferred, more preferably 27-42%, and even more preferably 29-40%.

[0051] Nb₂O₅ is an essential component of the glass of this invention, and a key component ensuring that the glass possesses high refractive index, low dispersion, low density, and low relative partial dispersion characteristics. Through dedicated research, the inventors discovered that when the Abbe number is in the range of 24–30, the contribution of Nb₂O₅ to the relative partial dispersion of the glass is approximately consistent with its contribution to the Abbe number; that is, as the amount of Nb₂O₅ in the glass increases, the deviation of the relative partial dispersion of the glass from the specified value (ΔP) decreases. g,FThe content of Nb2O5 remains essentially unchanged. Therefore, the content of Nb2O5 in this invention is 5-15%, preferably 6-14%, and more preferably 7-13%.

[0052] TiO2 can improve the refractive index and dispersion of glass, and enhance its resistance to crystallization. However, TiO2 in glass can lead to the formation of phosphorus oxides (P₂). g,F A sharp increase. When the TiO2 content in the glass exceeds 20%, the P of the glass... g,F The properties are difficult to meet design requirements; when the TiO2 content in the glass is less than 8%, the high refractive properties of the glass are difficult to meet design requirements. Therefore, the TiO2 content is 8-20%, preferably 9-19%, and more preferably 10-18%.

[0053] TiO2, Nb2O5, and La2O3 all contribute to increasing the refractive index in this invention, but TiO2 can lead to P... g,F A sharp increase, compared to Nb2O5 and La2O3 for glass P g,F The impact is relatively small. This invention limits the total content of TiO2, Nb2O5, and La2O3, specifically the ratio of Nb2O5+La2O3 (TiO2 / (Nb2O5+La2O3)) to 0.35–3.2, to improve the refractive index and phosphorus content of the glass. g,F It can meet the design requirements. Therefore, the preferred TiO2 / (Nb2O5+La2O3) ratio is 0.35 to 3.2, more preferably 0.4 to 3.0, and even more preferably 0.5 to 2.8.

[0054] WO3 can improve the refractive index and dispersion of glass, but it will cause the glass's phosphorus content to rise. g,F A sharp increase in WO3 content will also lead to a decrease in the light transmittance of the glass. Therefore, in this invention, the WO3 content is 0-5%, preferably 0-2%, and more preferably WO3-free.

[0055] Bi₂O₃ can improve the refractive index and dispersion of glass, but it will lead to changes in the phosphorus content of the glass. g,F The content of Bi2O3 increases sharply. In addition, Bi2O3 causes severe corrosion to platinum utensils during the smelting process, so its content is limited to 0-5%, preferably 0-2%, and more preferably does not contain Bi2O3.

[0056] Ta₂O₅ is a high-refractive-index, low-dispersion component that can reduce the phosphorus content of glass. g,F While Ta2O5 can improve the anti-crystallization properties and stability of glass, its high raw material cost greatly limits its use. In this invention, the Ta2O5 content is 0-5%, preferably 0-2%, and more preferably no Ta2O5 is present.

[0057] Nb₂O₅, TiO₂, WO₃, Bi₂O₃, and Ta₂O₅ can all increase the refractive index of glass, but these components have weak carrying capacity in the glass network, and excessive content will lead to poor anti-crystallization performance. Through extensive experimental research, the inventors found that when the ratio between the total content of Nb₂O₅, TiO₂, WO₃, Bi₂O₃, and Ta₂O₅ and the total content of SiO₂ and B₂O₃ (Nb₂O₅+TiO₂+WO₃+Bi₂O₃+Ta₂O₅) / (SiO₂+B₂O₃) is in the range of 0.3 to 1.8, the glass can obtain excellent melting performance and anti-crystallization performance. Therefore, the preferred ratio of (Nb2O5+TiO2+WO3+Bi2O3+Ta2O5) / (SiO2+B2O3) is 0.3 to 1.8, more preferably (Nb2O5+TiO2+WO3+Bi2O3+Ta2O5) / (SiO2+B2O3) is 0.4 to 1.6, and even more preferably (Nb2O5+TiO2+WO3+Bi2O3+Ta2O5) / (SiO2+B2O3) is 0.5 to 1.4.

[0058] Li₂O, an alkali metal oxide, is a key component in this invention for reducing the difficulty of glass production. Li₂O can be used as a flux, reducing the difficulty of glass preparation. Simultaneously, Li₂O can lower the high-temperature viscosity and transition temperature of glass, making glass production and processing easier. Through dedicated research, the inventors discovered that by including Li₂O in the glass, the accumulation effect of Li₂O can improve the weather resistance of the glass. However, if the Li₂O content is too high, it will cause a decrease in the acid resistance stability of the glass. Therefore, in the glass of this invention, the Li₂O content is 1.5–15%, preferably 2–13%, and more preferably 3–11%.

[0059] In this invention, SiO2 and ZrO2 can improve the acid resistance of glass, but they are also two components that are difficult to melt. B2O3 and Li2O have a fluxing effect, but excessive amounts will decrease the chemical stability of the glass. Extensive experimental research by the inventors has found that when the ratio of the total content of SiO2 and ZrO2 to the total content of B2O3 and Li2O (SiO2+ZrO2) / (B2O3+Li2O) is between 1.8 and 15.0, the glass can achieve excellent melting performance and chemical stability. Therefore, it is preferable that (SiO2+ZrO2) / (B2O3+Li2O) is 1.8 to 15.0, more preferably (SiO2+ZrO2) / (B2O3+Li2O) is 1.9 to 12.0, and even more preferably (SiO2+ZrO2) / (B2O3+Li2O) is 2.0 to 10.0.

[0060] Na₂O and K₂O can lower the fusing temperature and high-temperature viscosity of glass, reducing the difficulty of glass production. However, compared to the accumulation effect of Li₂O, Na₂O and K₂O cause the silicon network structure of glass to break down, leading to the degradation of P in the glass. g,F The content of Na2O in the glass of the present invention is 0-10%, preferably 0-8%, more preferably 0-6%; the content of K2O is 0-10%, preferably 0-8%, more preferably 0-6%.

[0061] Sb2O3 can be used as a clarifying agent in this invention to improve the clarification effect of glass. Its content ranges from 0 to 1%, preferably from 0 to 0.5%, and more preferably from 0 to 0.2%.

[0062] <Components that should not be present>

[0063] 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.

[0064] 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.

[0065] To achieve environmental friendliness, the optical glass of this invention does not contain As₂O₃ or PbO. Although As₂O₃ has the effect of eliminating bubbles and preventing glass discoloration, its addition increases the corrosion of platinum in the furnace, especially in platinum furnaces, leading to more platinum ions entering the glass and adversely affecting the service life of the platinum furnace. PbO can significantly improve the high refractive index and high dispersion properties of glass, but both PbO and As₂O₃ are environmental pollutants.

[0066] 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 situations are also within the scope of protection of this patent.

[0067] The performance of the optical glass of the present invention will now be described.

[0068] <Refractive Index and Abbe Number>

[0069] Refractive index of optical glass (n) d ) and Abbe number (ν) d Test according to the method specified in GB / T 7962.1—2010.

[0070] In some embodiments, the refractive index (n) of the optical glass of the present invention is... d The value is 1.87 to 1.93, preferably 1.88 to 1.92, and more preferably 1.89 to 1.91.

[0071] In some embodiments, the Abbe number (ν) of the optical glass of the present invention d The value is 24-30, preferably 25-29, and more preferably 26-28.

[0072] Relative Partial Dispersion

[0073] Relative partial dispersion (P) of optical glass g,F The calculation method is as follows: P g,F =(n g -n F ) / (n F -n C In the formula, n g n F With n C Test according to the method specified in GB / T 7962.1—2010.

[0074] In some embodiments, the relative partial dispersion (P0) of the optical glass of the present invention g,F )≤0.6090, preferably relative partial dispersion (P) g,F )≤0.6085, more preferably relative partial dispersion (P g,F ≤0.6080.

[0075] <Internal Transmittance>

[0076] Internal transmittance of glass (τ) 400The internal transmittance at 400nm of a 10mm thick sample was tested according to the method specified in GB / T 7962.12—2010.

[0077] In some embodiments, the internal transmittance (τ) of the optical glass of the present invention 400 The internal transmittance (τ) is preferably 0.68 or higher. 400 The internal transmittance (τ) is 0.70 or higher, and more preferably τ. 400 The value is above 0.72.

[0078] Anti-crystallization properties

[0079] The test method for the anti-crystallization performance of optical glass is as follows: Place the sample into T... g After being kept in a muffle furnace at +230℃ for 15 minutes, the sample was removed and cooled at room temperature. After double-sided polishing, the number of crystallized particles per cubic centimeter in the sample was observed (A).

[0080] In some embodiments, the number of crystals (A) in the optical glass of the present invention is 5 or less, preferably 3 or less, and more preferably 0.

[0081] <Weather resistance>

[0082] The weather resistance (CR) test method for glass is as follows: The sample is placed in a test chamber with a relative humidity of 90% and saturated water vapor, and the temperature is alternately cyclical at 40-50℃ every 1 hour for 15 cycles. The weather resistance category is determined based on the change in turbidity before and after the sample is placed in the chamber. The weather resistance classification is shown in the table below.

[0083]

[0084] In some embodiments, the optical glass of the present invention has a weather resistance (CR) of Class 2 or above, preferably Class 1.

[0085] <Acid resistance>

[0086] The acid resistance stability RA(S) of glass was tested according to the method specified in GB / T 7962.14—2010.

[0087] In some embodiments, the acid resistance stability of the optical glass of the present invention is Class 2 or above, preferably Class 1.

[0088] <Density>

[0089] The density (ρ) of the glass was tested according to the method specified in GB / T 7962.20—2010.

[0090] In some embodiments, the density (ρ) of the optical glass of the present invention is 3.95 g / cm³. 3The preferred value is 3.90 g / cm³. 3 The preferred value is 3.85 g / cm³. 3 the following.

[0091] [Manufacturing Method]

[0092] 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 conventional processes. It uses composite salts (such as carbonates, nitrates, and sulfates), hydroxides, oxides, etc., as raw materials. After being batched according to conventional methods, the batched material is added to a melting furnace at 1250–1450°C for melting. After clarification, stirring, 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.

[0093] II. Glass preforms and optical components

[0094] Glass preforms can be manufactured from the produced optical glass using methods such as grinding, hot pressing, or precision stamping. Specifically, glass preforms can be manufactured by machining the optical glass, such as grinding and polishing; or by hot pressing a preform made from optical glass for molding and then grinding it; or by precision stamping a preform made from a ground preform. It should be noted that the methods for preparing glass preforms are not limited to the methods described above.

[0095] 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.

[0096] 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.

[0097] 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.

[0098] III. Optical Instruments

[0099] The optical elements formed by the optical glass of this invention can be used to manufacture optical instruments such as photographic equipment, vehicle-mounted equipment, video recording equipment, display equipment, and monitoring equipment.

[0100] Because the optical glass of this invention has high refractive index and low relative partial dispersion, it is particularly suitable for use in telephoto lenses and high-definition switching lenses.

[0101] Example

[0102] <Example of Optical Glass>

[0103] To further illustrate and explain the technical solution of the present invention, the following non-limiting embodiments are provided.

[0104] In this embodiment, optical glasses with the properties shown in Tables 1 to 4 were 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 1 to 4.

[0105] Table 1.

[0106]

[0107]

[0108] Table 2.

[0109]

[0110]

[0111] Table 3.

[0112]

[0113]

[0114] Table 4.

[0115]

[0116]

[0117] <Example of Glass Prefabricated Components>

[0118] The glass obtained from Examples 1 to 40 of optical glass is used, for example, by grinding, or by molding such as hot pressing or precision stamping, to produce 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.

[0119] <Optical Component Examples>

[0120] Annealing these preforms obtained from the above glass preform examples reduces internal deformation of the glass while fine-tuning them so that optical properties such as refractive index reach the desired values.

[0121] 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.

[0122] <Examples of Optical Instruments>

[0123] 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 molar percentage, contains: SiO2: 25–40%; B2O3: 1–8%; La2O3: 1–8%; BaO: 1–6%; CaO: 5–25%; Nb2O5: 5–15%; TiO2: 8–20%; Li2O: 1.5–15%, of which SiO2+B2O3 accounts for 27–45%.

2. The optical glass according to claim 1, characterized in that, Its components, expressed as molar percentages, also include: Al₂O₃: 0–5%; and / or Gd₂O₃: 0–8%; and / or Y₂O₃: 0–8%; and / or SrO: 0–15%; and / or MgO: 0–10%; and / or ZnO: 0–8%; and / or ZrO₂: 0–5%; and / or WO₃: 0–5%; and / or Bi₂O₃: 0–5%; and / or Ta₂O₅: 0–5%; and / or Na₂O: 0–10%; and / or K₂O: 0–10%; and / or Sb₂O₃: 0–1%.

3. Optical glass, characterized in that, Its composition, expressed as a molar percentage, is as follows: SiO2: 25–40%; B2O3: 1–8%; La2O3: 1–8%; BaO: 1–6%; CaO: 5–25%; Nb2O5: 5–15%; TiO2: 8–20%; Li2O: 1.5–15%; Al2O3: 0–5%; Gd2O3: 0–8%; Y2O3: 0–8%. Composition: SrO: 0-15%; MgO: 0-10%; ZnO: 0-8%; ZrO2: 0-5%; WO3: 0-5%; Bi2O3: 0-5%; Ta2O5: 0-5%; Na2O: 0-10%; K2O: 0-10%; Sb2O3: 0-1%, of which SiO2+B2O3 is 27-45%.

4. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a molar percentage, wherein: SiO2+B2O3 is 28-43%, preferably 30-41%; and / or SiO2+ZrO2 is 25-44%, preferably 27-42%, more preferably 29-40%; and / or RO is 10-40%, preferably 12-38%, more preferably 15-35%; and / or Re2O3 is 1-20%, preferably 1.2-18%, more preferably Re2O3. The content of 2O3 is 1.5-15%; and / or B2O3+La2O3 is 2-14%, preferably B2O3+La2O3 is 3-13%, more preferably B2O3+La2O3 is 4-12%; and / or B2O3+Al2O3 is 1-12%, preferably B2O3+Al2O3 is 2-11%, more preferably B2O3+Al2O3 is 3-10%, wherein RO is the total content of BaO, SrO, CaO and MgO, and Re2O3 is the total content of La2O3, Gd2O3 and Y2O3.

5. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as mole percentages and satisfy one or more of the following six conditions: 1) The SiO2 / B2O3 ratio is 3.5 to 38.0, preferably 3.8 to 35.0, and more preferably 4.0 to 30.0; 2) The ratio of (SiO2+ZrO2) / (B2O3+Li2O) is 1.8 to 15.0, preferably 1.9 to 12.0, and more preferably 2.0 to 10.0; 3) The ratio of (Nb2O5+TiO2+WO3+Bi2O3+Ta2O5) / (SiO2+B2O3) is 0.3 to 1.8, preferably 0.4 to 1.6, and more preferably 0.5 to 1.

4. 4) The ratio of TiO2 / (Nb2O5+La2O3) is 0.35 to 3.2, preferably 0.4 to 3, and more preferably 0.5 to 2.8; 5) The CaO / RO ratio is 0.25 to 0.95, preferably 0.3 to 0.8, and more preferably 0.4 to 0.7; 6) The BaO / RO ratio is 0.03 to 0.5, preferably 0.04 to 0.4, and more preferably 0.05 to 0.3, wherein RO is the total content of BaO, SrO, CaO, and MgO.

6. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as molar percentages, wherein: SiO2: 27–38%, preferably SiO2: 29–36%; and / or B2O3: 2–7%, preferably B2O3: 3–6%; and / or La2O3: 2–7%, preferably La2O3: 3–6%; and / or BaO: 1.5–5%, preferably BaO: 2–4%; and / or CaO: 7–22%, preferably CaO: 9–20%; and / or Nb2O5: 6–14%, preferably Nb2O5: 7–13%; and / or TiO2: 9–19%, preferably TiO2: 10–18%; and / or Li2O: 2–13%, preferably Li2O: 3–11%; and / or Al2O3: 0–3%; and / or Gd2O3: 0–6%. The preferred compounds are Gd₂O₃: 0–4%; and / or Y₂O₃: 0–6%, preferably Y₂O₃: 0–4%; and / or SrO: 1–14%, preferably SrO: 2–12%; and / or MgO: 0–8%, preferably MgO: 0–5%; and / or ZnO: 0–6%, preferably ZnO: 0–4%; and / or ZrO₂: 0–4%, preferably ZrO₂: 0–3%; and / or WO₃: 0–2%; and / or Bi₂O₃: 0–2%; and / or Ta₂O₅: 0–2%; and / or Na₂O: 0–8%, preferably Na₂O: 0–6%; and / or K₂O: 0–8%, preferably K₂O: 0–6%; and / or Sb₂O₃: 0–0.5%, preferably Sb₂O₃: 0–0.2%.

7. The optical glass according to any one of claims 1 to 3, characterized in that, Its components do not contain Al2O3; and / or do not contain WO3; and / or do not contain Bi2O3; and / or do not contain Ta2O5.

8. 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 preferred refractive index is 1.87–1.

93. d The refractive index n is 1.88 to 1.92, and more preferably 1.88 to 1.

92. d The Abbe number is 1.89–1.

91. d The optimal Abbe number is ν, which should be between 24 and 30. d The value is 25 to 29, with the Abbe number ν being more preferred. d It ranges from 26 to 28.

9. The optical glass according to any one of claims 1 to 3, characterized in that, The relative partial dispersion P of the optical glass g,F ≤0.6090, preferred relative partial dispersion P g,F ≤0.6085, more preferably relative partial dispersion P g,F ≤0.6080; and / or internal transmittance τ 400 A value above 0.68 is preferred for internal transmittance τ. 400 A value of 0.70 or higher, and preferably an internal transmittance τ 400 The density is 0.72 or higher; and / or the weather resistance CR is Class 2 or higher, preferably Class 1; and / or the acid resistance stability is Class 2 or higher, preferably Class 1; and / or the density is 3.95 g / cm³. 3 The preferred density is 3.90 g / cm³. 3 The preferred density is 3.85 g / cm³. 3 the following.

10. An optical element, characterized in that, It is made of the optical glass described in any one of claims 1 to 9.

11. An optical instrument, characterized in that, It contains the optical glass according to any one of claims 1 to 9, and / or contains the optical element according to claim 10.

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