Optical glass

Abstract

To provide an optical glass having excellent crystallization resistance, high refractive index, high dispersion, and relatively low relative partial dispersion.SOLUTION: Provided is an optical glass containing the following components in weight percentage: SiO2: 25-45%; ZrO2: 2-15%; Nb2O5: 35-60%; Li2O: 1-10%; Na2O: 2-15%; K2O: 0-10%. By adding appropriate amounts of components such as SiO2 and alkali metal oxides, the optical glass of the present invention has excellent crystallization resistance. By adding oxide components such as Nb2O5 and ZrO2 having high refractive index, an optical glass with high refractive index and high dispersion is obtained, and by reasonable component design, the optical glass of the present invention has relatively low relative partial dispersion.SELECTED DRAWING: None

Description

[Technical Field]

[0001] The present invention relates to optical glass, and more particularly to high-refractive-index, high-dispersion optical glass that is highly resistant to devitrification. [Background technology]

[0002] In optical systems with long focal lengths, large fields of view, and high precision, secondary spectrum is the main factor affecting the imaging quality. Correcting secondary spectrum is a special problem in the design of long focal length optical systems, and it is also a relatively difficult problem to solve. Correcting secondary spectrum in optical systems depends heavily on the selection of glass materials. High refractive index, high dispersion, and low relative partial dispersion (P g,F ) glasses are advantageous in removing secondary spectra when applied to coupling lenses, simplifying and optimizing the optical system and improving imaging quality.

[0003] The secondary pressing method has advantages such as low manufacturing costs, low production difficulty, and ease of mass production, and is therefore widely used in the manufacture of glass elements. The secondary pressing method is a production method in which a glass material is placed in a mold, heated above its softening point, and pressed into a desired shape. This production method requires the glass to be heated to a temperature 100 to 200°C higher than its transition temperature. Under these conditions, the glass must already have a certain degree of fluidity and excellent devitrification resistance; otherwise, there is a risk of devitrification during the secondary pressing process and the glass will be discarded. Patent Document 1 discloses an optical glass with relatively low relative partial dispersion, containing, by weight, 5.0% to 55.0% B2O3 and 15% to 60% rare earth oxides. This optical glass has low devitrification resistance and is therefore at high risk of devitrification during the secondary pressing process. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] Chinese Patent Application Publication No. 104583142 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, high dispersion optical glass that has excellent resistance to devitrification and relatively low relative partial dispersion. [Means for solving the problem]

[0006] The technical solutions adopted by the present invention to solve the technical problems are as follows: Optical glass containing the following components by weight: SiO2: 25-45%, ZrO2: 2-15%, Nb2O5: 35-60%, Li2O: 1-10%, Na2O: 2-15%, K2O: 0-10%.

[0007] The optical glass further contains the following components in weight percent: B2O3: 0-10%, and / or Al2O3: 0-5%, and / or La2O3: 0-10%, and / or Gd2O3: 0-10%, and / or Y2O3: 0-10%, and / or Yb2O3: 0-10%, and / or BaO: 0-10%, and / or SrO: 0-10%, and / or CaO: 0-10%, and / or MgO: 0-5%, and / or ZnO: 0-10%, and / or TiO2: 0-10%, and / or WO3: 0-10%, and / or Bi2O3: 0-5%, and / or Ta2O5: 0-5%, and / or Sb2O3: 0-1%.

[0008] Optical glass consisting of the following components by weight: SiO2: 25-45%, ZrO2: 2-15%, Nb2O5: 35-60%, Li2O: 1-10%, Na2O: 2-15%, K2O: 0-10%, B2O3: 0-10%, Al2O3: 0-5%, La2O3: 0-10%, Gd2O3: 0-10%, Y2O3: 0-10%, Yb2O3: 0-10%, BaO: 0-10%, SrO: 0-10%, CaO: 0-10%, MgO: 0-5%, ZnO: 0-10%, TiO2: 0-10%, WO3: 0-10%, Bi2O3: 0-5%, Ta2O5: 0-5%, Sb2O3: 0-1%.

[0009] The optical glass further comprises the following components in weight percent and satisfies one or more of the following nine conditions: 1) B2O3+Al2O3 is 0-12%; 2) Re2O3 is 0-15%; 3) RO is 0-10%; 4) SiO2+ZrO2 is 30~55%; 5) Nb2O5+ZrO2 is 40-70%; 6) TiO2+WO3+Bi2O3 is 0~10%; 7) Rn2O is 6-20%; 8) (SiO2+ZrO2) / Rn2O is 1.5~8.0; 9) ZrO2 / Rn2O is 0.1~2.3, The Re2O3 is the total content of La2O3, Gd2O3, and Y2O3, the RO is the total content of BaO, SrO, CaO, and MgO, and the Rn2O is the total content of Li2O, Na2O, and K2O.

[0010] The optical glass further contains the following components in weight percent: SiO2: 28 to 42%, and / or ZrO2: 3 to 12%, and / or Nb2O5: 38 to 57%, and / or Li2O: 2 to 8%, and / or Na2O: 4 to 13%, and / or K2O: 0.5 to 8%, and / or B2O3: 0 to 5%, and / or Al2O3: 0 to 2%, and / or La2O3: 0 to 5%, and / or Gd2O3: 0 to 5%, and / or Y2O3: 0-5%, and / or Yb2O3: 0-5%, and / or BaO: 0-5%, and / or SrO: 0-5%, and / or CaO: 0-8%, and / or MgO: 0-3%, and / or ZnO: 0-5%, and / or TiO2: 0-7%, and / or WO3: 0-5%, and / or Ta2O5: 0-2%, and / or Sb2O3: 0-0.5%.

[0011] The optical glass further comprises the following components in weight percent and satisfies one or more of the following nine conditions: 1) B2O3+Al2O3 is 0-6%; 2) Re2O3 is 0-8%; 3) RO is 0-8%; 4) SiO2+ZrO2 is 33~52%; 5) Nb2O5+ZrO2 is 45-65%; 6) TiO2+WO3+Bi2O3 is 0~7%; 7) Rn2O is 10-18%; 8) (SiO2+ZrO2) / Rn2O is 1.8~6.5; 9) ZrO2 / Rn2O is 0.2~1.8, The Re2O3 is the total content of La2O3, Gd2O3, and Y2O3, the RO is the total content of BaO, SrO, CaO, and MgO, and the Rn2O is the total content of Li2O, Na2O, and K2O.

[0012] The optical glass further contains the following components in weight percent: SiO2: 30 to 40%; and / or ZrO2: 4 to 10%; and / or Nb2O5: 41 to 54%; and / or B2O3: 0 to 3%; and / or Li2O: 3 to 6%; and / or Na2O: 5 to 12%; and / or K2O: 1 to 6%; and / or BaO: 0 to 2%; and / or CaO: 0 to 5%; and / or ZnO: 0 to 2%; and / or TiO2: 0 to 4%; and / or Sb2O3: 0 to 0.1%.

[0013] The optical glass further comprises the following components in weight percent and satisfies one or more of the following seven conditions: 1) RO is 0-5%; 2) SiO2+ZrO2 is 36-49%; 3) Nb2O5+ZrO2 is 50-60%; 4) TiO2+WO3+Bi2O3 is 0~4%; 5) Rn2O is 12-16%; 6) (SiO2+ZrO2) / Rn2O is 2.0~5.0; 7) ZrO2 / Rn2O is 0.3~1.3, The RO is the total content of BaO, SrO, CaO, and MgO, and the Rn2O is the total content of Li2O, Na2O, and K2O.

[0014] The optical glass further comprises: no B2O3, no Al2O3, no La2O3, no Gd2O3, no Y2O3, no Yb2O3, no MgO, no SrO, no WO3, no Bi2O3, no Ta2O5, and / or no Re2O3, wherein the Re2O3 content is the total content of La2O3, Gd2O3, and Y2O3.

[0015] Furthermore, the refractive index n of the optical glass d is 1.74 to 1.82, preferably the refractive index n d is 1.76 to 1.80, and the Abbe number ν d is 25 to 32, and preferably the Abbe number ν d is 27 to 30.

[0016] Furthermore, the relative partial dispersion P g,F ≦0.6497-0.001703×ν d , preferably P g,F ≦0.6477-0.001703×ν d、 And / or the λ5 of the optical glass is 360 nm or less, preferably 350 nm or less.

[0017] A glass preform manufactured from the above optical glass.

[0018] An optical element manufactured from the above optical glass or the above glass preform.

[0019] An optical instrument comprising the optical glass and / or the optical element. [Effects of the Invention]

[0020] The beneficial effects of the present invention are as follows: By adding appropriate amounts of components such as SiO2 and alkali metal oxides, the optical glass has excellent resistance to devitrification; by adding oxide components with high refractive index such as Nb2O5 and ZrO2, the optical glass has a high refractive index and high dispersion; and by rationally designing the components, the glass has low relative partial dispersion. DETAILED DESCRIPTION OF THE INVENTION

[0021] Hereinafter, embodiments of the optical glass according to the present invention will be described in detail, but the present invention is not limited to the embodiments described below, and can be practiced by 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. Hereinafter, the optical glass of the present invention may also be referred to simply as glass.

[0022] I. Optical Glass The range of components of the 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. "Converted into an oxide composition" here refers to the case where the total weight of the oxide material when the oxides, complex salts, hydroxides, etc. used as raw materials for the optical glass composition of the present invention are decomposed and converted into oxides during melting is taken as 100%.

[0023] 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.

[0024] <Required and optional ingredients> SiO2 is a component that forms a glass network, improves the chemical stability and weather resistance of glass, and maintains its devitrification resistance. If the SiO2 content is less than 25%, it is difficult to achieve the above effects. Therefore, in the present invention, the lower limit of the SiO2 content is 25%, preferably 28%, and more preferably 30%. If the SiO2 content exceeds 45%, the glass becomes difficult to melt, making it difficult to obtain the refractive index expected in the present invention. Therefore, the upper limit of the SiO2 content is 45%, preferably 42%, and more preferably 40%.

[0025] B2O3 can lower the high-temperature viscosity and transition temperature of glass while reducing the melting difficulty of the glass. However, in the present invention, when B2O3 is in a [BO3] coordination state, the relative partial dispersion of the glass becomes high. Therefore, to ensure a low relative partial dispersion of the glass, the content of B2O3 in the present invention is 10% or less, preferably 5% or less, more preferably 3% or less, and even more preferably no B2O3.

[0026] Although Al2O3 can improve the weather resistance of glass, it also increases the melting temperature and high-temperature viscosity of the glass, making production more difficult. If the Al2O3 content exceeds 5%, the melting property of the glass tends to deteriorate and the devitrification resistance tends to decrease. Therefore, in the present invention, the Al2O3 content is 0 to 5%, preferably 0 to 2%, and more preferably no Al2O3 is contained.

[0027] In some embodiments of the present invention, it is advantageous to control the total content of B2O3 and Al2O3, B2O3+Al2O3, to 12% or less to maintain the relative partial dispersion of the glass within the design range, preferably B2O3+Al2O3 is 0-6%.

[0028] La2O3 is a high-refractive-index, low-dispersion component, and its use in glass can significantly reduce the relative partial dispersion of the glass. However, if its content is too high, the dispersion of the glass decreases, making it difficult to achieve the high-refractive-index, high-dispersion optical properties expected by the present invention. Therefore, in the present invention, the La2O3 content is 10% or less, preferably 5% or less, and more preferably, no La2O3 is contained.

[0029] Gd2O3 is a high refractive index, low dispersion component, and its use in glass reduces the relative partial dispersion of the glass. However, its high cost limits its use in glass. Therefore, the Gd2O3 content should be 0 to 10%, preferably 0 to 5%, and more preferably, no Gd2O3.

[0030] Although Y2O3 can improve the meltability of glass and enhance its weather resistance, if its content is too high, the dispersion of the glass decreases, making it impossible to achieve the high refractive index and high dispersion optical properties expected by the present invention. Therefore, the Y2O3 content should be 0 to 10%, preferably 0 to 5%, and more preferably be free of Y2O3.

[0031] Although La2O3, Gd2O3, and Y2O3 can increase the refractive index and reduce the relative partial dispersion when used in glass, if their content is too high, it becomes difficult to achieve the high refractive index, high dispersion optical properties expected by the present invention. Therefore, in the present invention, the total content of La2O3, Gd2O3, and Y2O3, Re2O3, is preferably 0 to 15%, more preferably 0 to 8%, and even more preferably no Re2O3 is contained.

[0032] Although the use of Yb2O3 in glass can increase the refractive index of the glass, it has a significant absorption peak in the near-infrared region, which changes the spectral composition of transmitted light when used in optical elements and further affects the reduction effect of images. Therefore, the Yb2O3 content range is limited to 0 to 10%, preferably 0 to 5%, and more preferably, no Yb2O3 is contained.

[0033] BaO is a low-cost, readily available raw material, and its use in glass can significantly improve the refractive index of the glass. However, BaO is disadvantageous in lowering the density of the glass, and if the BaO content is too high, the weather resistance of the glass rapidly deteriorates. Therefore, the BaO content is limited to 0 to 10%, preferably 0 to 5%, and more preferably 0 to 2%.

[0034] An appropriate amount of SrO can increase the weather resistance of glass and reduce the density of glass, but SrO is expensive, and a high SrO content increases the manufacturing cost of glass. Therefore, the SrO content is limited to 0 to 10%, preferably 0 to 5%, and more preferably no SrO is contained.

[0035] CaO can increase the hardness, mechanical strength, and weather resistance of glass. More importantly, CaO is more advantageous than BaO and SrO in reducing the density of glass. CaO is also advantageous for controlling and adjusting the optical constants during the production process. However, if the CaO content is too high, it becomes difficult to melt the glass and tends to form a hard calcium-rich shell in the molten pool during the production process. Therefore, the CaO content is limited to 0-10%, preferably 0-8%, and more preferably 0-5%.

[0036] Although MgO helps to improve the weather resistance of glass, a high MgO content causes the refractive index of the glass to fail to meet design requirements, reducing the devitrification resistance and stability of the glass and rapidly increasing the cost of the glass. Therefore, the MgO content is limited to 0-5%, preferably 0-3%, and more preferably no MgO is added.

[0037] BaO, SrO, CaO, and MgO all belong to alkaline earth metal oxides, and in the present invention, in order to obtain excellent resistance to devitrification and mechanical strength, the total content RO of alkaline earth metal oxides is controlled within the range of preferably 0 to 10%, more preferably 0 to 8%, and even more preferably 0 to 5%.

[0038] ZnO can improve the acid stability of glass, enhance its weather resistance, and lower the glass transition temperature, but if its content is too high, it can increase corrosion of platinum containers during melting and shorten the service life of the melting furnace. Therefore, the ZnO content in the glass of the present invention is 0 to 10%, preferably 0 to 5%, and more preferably 0 to 2%.

[0039] ZrO2 improves the weather resistance of glass and enhances its resistance to devitrification. Furthermore, the use of ZrO2 in glass can significantly reduce the relative partial dispersion of the glass. However, the solubility of ZrO2 in this glass is not high, and if the content is too high, it will be liberated outside the glass system, forming crystal nuclei and further reducing the devitrification resistance of the glass. Therefore, in the present invention, the ZrO2 content is 2 to 15%, preferably 3 to 12%, and more preferably 4 to 10%.

[0040] SiO2 and ZrO2 can improve the weather resistance of glass, but in the present invention, SiO2 and ZrO2 are also two components that are difficult to melt. As a result of extensive experimental research, the inventors have found that in some embodiments, when the total content of SiO2 and ZrO2, SiO2 + ZrO2, is 30 to 55%, the glass can achieve excellent weather resistance and good productivity. Therefore, SiO2 + ZrO2 is preferably 30 to 55%, more preferably 33 to 52%, and even more preferably 36 to 49%.

[0041] Nb2O5 is a necessary component of the glass of the present invention, and is an important component that ensures that the glass has high refractive index, high dispersion, and low relative partial dispersion characteristics. As a result of extensive experimental research by the present inventors, it has been found that when the Abbe number is between 25 and 32, the contribution of Nb2O5 to the relative partial dispersion of the glass is nearly equal to its contribution to the Abbe number. In other words, as Nb2O5 grows in the glass, the relative partial dispersion deviation value (ΔP g,F) hardly changes. Therefore, in the present invention, the content of Nb2O5 is 35 to 60%, preferably 38 to 57%, and more preferably 41 to 54%.

[0042] Nb2O5 and ZrO2 are important components for maintaining the low relative partial dispersion performance of the present invention. In some embodiments of the present invention, when the total content of Nb2O5 and ZrO2 (Nb2O5 + ZrO2) is controlled within the range of 40 to 70%, the refractive index, dispersion, and relative partial dispersion of the glass can well meet the design requirements. Therefore, Nb2O5 + ZrO2 is preferably 40 to 70%, more preferably 45 to 65%, and even more preferably 50 to 60%.

[0043] TiO2 can increase the refractive index and dispersion of glass and improve the devitrification resistance of glass. However, when TiO2 is used in glass, P g,F The P of the glass increases sharply when the TiO2 content in the glass exceeds 10%. g,F The properties will not satisfy the design requirements. Therefore, the content of TiO2 is 0 to 10%, preferably 0 to 7%, and more preferably 0 to 4%.

[0044] WO3 can increase the refractive index and dispersion of glass, but the P g,F If the content of WO3 in the glass increases sharply, the light transmittance of the glass may decrease. Therefore, in the present invention, the WO3 content is 0 to 10%, preferably 0 to 5%, and more preferably no WO3 is contained.

[0045] Bi2O3 can increase the refractive index and dispersion of glass, but the P g,F Furthermore, since Bi2O3 causes relatively serious corrosion to the platinum container during melting, its content is limited to 5% or less, and it is preferable that Bi2O3 is not included.

[0046] TiO2, WO3 and Bi2O3 can all increase the refractive index and dispersion of glass, but g,FTherefore, in the present invention, the total content of TiO2, WO3 and Bi2O3 (TiO2+WO3+Bi2O3) is 0 to 10%, more preferably 0 to 7%, and even more preferably 0 to 4%.

[0047] Ta2O5 is a high refractive index and high dispersion component, and g,F The Ta2O5 content can be reduced, and at the same time, Ta2O5 can improve the devitrification resistance of the glass and enhance the stability of the glass. However, the high cost of the raw material significantly limits the use of Ta2O5. Therefore, in the present invention, the Ta2O5 content is 0 to 5%, preferably 0 to 2%, and more preferably Ta2O5 is not included.

[0048] Li2O is an alkali metal oxide and is an important component in the present invention that reduces the difficulty of glass production. Li2O can be used as a melting aid, reducing the difficulty of glass melting. Li2O also lowers the high-temperature viscosity and transition temperature of glass, facilitating glass production and processing. As a result of extensive experimental research, the present inventors have found that adding Li2O to glass can utilize the Li2O accumulation effect to improve the weather resistance of glass. However, if the Li2O content is too high, the acid resistance stability of the glass will decrease. Therefore, the Li2O content in the glass of the present invention is 1 to 10%, preferably 2 to 8%, and more preferably 3 to 6%.

[0049] Na2O and K2O can also lower the melting temperature and high-temperature viscosity of glass, reducing the difficulty of glass production. However, compared with the cumulative effect of Li2O, Na2O and K2O destroy the silicon network structure of glass, reducing the P of glass. g,F Therefore, in the glass of the present invention, the Na2O content is 2 to 15%, preferably 4 to 13%, and more preferably 5 to 12%, and the K2O content is 0 to 10%, preferably 0.5 to 8%, and more preferably 1 to 6%.

[0050] Li2O, Na2O, and K2O are all alkali metal oxides, which can reduce the difficulty of glass production, but if their content is too high, the chemical stability of the glass decreases. Therefore, in the present invention, the total content of Li2O, Na2O, and K2O (Rn2O) is preferably controlled within the range of 6 to 20%, more preferably 10 to 18%, and even more preferably 12 to 16%.

[0051] As a result of extensive experimental research, the inventors have found that the alkali metal oxide Rn2O promotes the melting of SiO2 and ZrO2 and reduces the difficulty of glass melting. Furthermore, when the ratio of the total content of SiO2 and ZrO2 (SiO2 + ZrO2) to the content of Rn2O, (SiO2 + ZrO2) / Rn2O, is 1.5 to 8.0, the glass can exhibit excellent melting properties and devitrification resistance, preferably 1.8 to 6.5, and more preferably 2.0 to 5.0.

[0052] The silicate glass network structure does not have a high ZrO2 support capacity, and if the ZrO2 content is too high, it is prone to precipitate and form stones during melting. After extensive experimental research, the inventors have found that in some embodiments, the alkali metal oxide Rn2O can improve the ZrO2 support capacity of the silicate glass, and that when the ratio of the ZrO2 content to the Rn2O content, ZrO2 / Rn2O, is 0.1 to 2.3, the ZrO2 support capacity of the glass system of the present invention can be improved and the chemical stability of the glass can be enhanced. Preferably, ZrO2 / Rn2O is 0.2 to 1.8, and more preferably, ZrO2 / Rn2O is 0.3 to 1.3.

[0053] Sb2O3 can be used as a fining agent in the present invention to enhance the fining effect of glass, and its content ranges from 0 to 1%, preferably from 0 to 0.5%, and more preferably from 0 to 0.1%.

[0054] <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.

[0055] 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.

[0056] To be environmentally friendly, the optical glass of the present invention does not contain As2O3 or PbO. While As2O3 has the effect of removing bubbles and preventing coloration of the glass, the addition of As2O3 increases platinum corrosion in glass melting furnaces, especially platinum melting furnaces, allowing more platinum ions to enter the glass and adversely affecting the service life of the platinum melting furnace. While PbO significantly enhances the high refractive index and high dispersion of the glass, both PbO and As2O3 are environmentally polluting substances.

[0057] 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 manufacturing the glass may be present in small or trace amounts in the final glass, and these are also within the scope of the patent of this invention. The properties of the optical glass of the present invention are described below.

[0058] <Refractive index and Abbe number> The refractive index (nd) and Abbe number (ν d) has been tested according to the method specified in GB / T 7962.1-2010. In some embodiments, the refractive index (n d ) is 1.74 to 1.82, preferably 1.76 to 1.80. In some embodiments, the Abbe number (ν d ) is 25 to 32, preferably 27 to 30.

[0059] <Relative partial dispersion> Relative partial dispersion (P g,F ) calculation formula: P g,F =(n g -n F ) / (n F -n C ), where n g , n F and n C has been tested according to the method specified in GB / T 7962.1-2010. In some embodiments, the relative partial dispersion (P g,F )≦0.6497-0.001703×ν d , preferably P g,F ≦0.6477-0.001703×ν d is.

[0060] <Transmittance> Glass transmittance (λ5) is used to measure the short-wave transmittance of glass. The specific test method is to place a 10 mm thick sample with both sides polished on a spectrophotometer to test the glass transmittance, and λ5 refers to the corresponding wavelength when the glass transmittance reaches 5%. In some embodiments, the λ5 of the optical glass of the present invention is 360 nm or less, preferably 350 nm or less.

[0061] <Devitrification resistance> The devitrification resistance test method for optical glass is as follows. gThe sample is placed in a muffle furnace at +230°C and kept at this temperature for 15 minutes, then removed, cooled at room temperature, and polished on both sides, after which the number of precipitated particles (A) per cubic centimeter within the sample is observed. In some embodiments, the number (A) of precipitated particles of the optical glass of the present invention is 5 or less, preferably 2 or less, and more preferably 0.

[0062] [Manufacturing method] The method for producing the optical glass of the present invention is as follows. The glass of the present invention is produced using conventional raw materials and processes from complex salts (carbonates, nitrates, sulfates), hydroxides, and oxides. After blending them using conventional methods, the prepared furnace material is placed in a melting furnace at 1250 to 1450°C and melted. The mixture is then clarified, stirred, and homogenized to obtain a homogeneous molten glass free of bubbles and unmelted material. This molten glass is then cast into a mold and annealed. Those skilled in the art will be able to select the raw materials, production method, and process parameters as appropriate according to actual needs.

[0063] II. Glass preforms and optical elements A glass preform can be produced from the produced optical glass using press molding means such as polishing, hot press molding, precision press molding, etc. That is, an optical preform can be produced from the optical glass by mechanical processing such as grinding or polishing, or a blank for press molding can be produced from the optical glass, and this blank can be hot press molded and then polished to produce an optical preform, or the polished blank can be precision press molded to produce an optical preform. Note that the means for producing the optical preform are not limited to the above means.

[0064] As described above, the optical glass of the present invention is useful for various optical elements and optical designs, and it is particularly preferable to form a blank from the optical glass of the present invention and use this blank to carry out hot press molding, precision press molding, or the like to produce optical elements such as lenses and prisms.

[0065] The optical preform and optical element of the present invention are both formed from the optical glass of the present invention. The optical preform of the present invention has the excellent properties of optical glass, and the optical element of the present invention has the excellent properties of optical glass, making it possible to provide optical elements such as various lenses and prisms with high optical value. 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.

[0066] III.Optical equipment Optical elements formed from the optical glass of the present invention can be used to fabricate optical equipment such as photographic devices, in-vehicle devices, imaging devices, display devices, and monitor devices. The optical glass of the present invention has a high refractive index, high dispersion, and low relative partial dispersion, and is therefore particularly suitable for long focal length lenses and high-definition interchangeable lenses.

[0067] <<Example>> <Optical Glass Examples> To further clearly illustrate the technical solutions of the present invention, the following non-limiting examples are provided. In the present examples, the optical glass manufacturing method described above was used to obtain optical glasses having the compositions shown in Tables 1 to 4. The properties of each glass were measured using the test methods described in the present invention, and the results are shown in Tables 1 to 4.

[0068] [Table 1]

[0069] [Table 2]

[0070] [Table 3]

[0071] [Table 4]

[0072] <Example of glass preform> The glasses obtained in Examples 1 to 40 of the optical glass are subjected to polishing, hot press molding, precision press molding or other press molding means to produce various lenses such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, plano-concave lenses, and preforms such as prisms.

[0073] <Optical element examples> The preform obtained in the above optical preform example is tempered to fine-tune the refractive index while reducing strain inside the glass so that the optical properties such as the refractive index reach the desired values. Each preform is then ground and polished to produce various lenses and prisms, including concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses.Anti-reflection coatings can also be applied to the surfaces of the resulting optical elements.

[0074] <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. An optical glass comprising, in weight percent: SiO 2 :25~45%、ZrO 2 :2~15%、Nb 2 O 5 :35~57%、Li 2 O:1~10%、Na 2 O:2~15%、K 2 O:0~10%.

2. 10. The optical glass of claim 1 further comprising the following components in weight percent: B 2 O 3 : 0 to 10%, and / or Al 2 O 3 : 0 to 5%, and / or La 2 O 3 : 0-10%, and / or Gd 2 O 3 : 0 to 10%, and / or Y 2 O 3 : 0 to 10%, and / or Yb 2 O 3 : 0-10%, and / or BaO: 0-10%, and / or SrO: 0-10%, and / or CaO: 0-10%, and / or MgO: 0-5%, and / or ZnO: 0-10%, and / or TiO 2 : 0-10%, and / or WO 3 : 0 to 10%, and / or Bi 2 O 3 : 0 to 5%, and / or Ta 2 O 5 : 0 to 5% and / or Sb 2 O 3 : 0 to 1%.

3. An optical glass consisting of the following components in weight percent: SiO 2 :25~45%、ZrO 2 :2~15%、Nb 2 O 5 :35~57%、Li 2 O:1~10%、Na 2 O:2~15%、K 2 O:0~10%、B 2 O 3 :0~10%、Al 2 O 3 :0~5%、Sun 2 O 3 :0~10%、Gd 2 O 3 :0~10%、Y 2 O 3 :0~10%、Yb 2 O 3 :0~10%、BaO:0~10%、SrO:0~10%、CaO:0~10%、MgO:0~5%、ZnO:0~10%、TiO 2 :0~10%、WO 3 :0~10%、Bi 2 O 3 :0~5%、Ta 2 O 5 :0~5%、Sb 2 O 3 :0~1%.

4. 4. The optical glass according to claim 1, comprising the following components in weight percent and satisfying one or more of the following nine conditions: 1) B 2 EITHER 3 +To 2 EITHER 3 は0~12%; 2) Re 2 O 3 is 0-15%; 3) RO is 0-10%; 4) SiO 2 +ZrO 2 is 30-55%; 5) Nb 2 O 5 +ZrO 2 is 40-70%; 6) TiO 2 +WO 3 +Bi 2 O 3 is 0-10%; 7) Rn 2 O 6–20%; 8) (SiO 2 +ZrO 2 ) / Rn 2 O is 1.5–8.0; 9) ZrO 2 / Rn 2 O is 0.1 to 2.3, The above-mentioned Re 2 O 3 La 2 O 3 , Gd 2 O 3 , Y 2 O 3 RO is the total content of BaO, SrO, CaO, and MgO, Rn 2 O is Li 2 O, Na 2 OK 2 The total O content.

5. The optical glass according to any one of claims 1 to 3, comprising the following components in weight percent: SiO 2 : 28-42%, and / or ZrO 2 : 3 to 12%, and / or Nb 2 O 5 : 38-57%, and / or Li 2 O: 2-8% and / or Na 2 O: 4-13% and / or K 2 O: 0.5-8% and / or B 2 O 3 : 0 to 5%, and / or Al 2 O 3 : 0 to 2%, and / or La 2 O 3 : 0-5%, and / or Gd 2 O 3 : 0 to 5%, and / or Y 2 O 3 : 0 to 5%, and / or Yb 2 O 3 : 0-5%, and / or BaO: 0-5%, and / or SrO: 0-5%, and / or CaO: 0-8%, and / or MgO: 0-3%, and / or ZnO: 0-5%, and / or TiO 2 : 0-7%, and / or WO 3 : 0 to 5%, and / or Ta 2 O 5 : 0 to 2% and / or Sb 2 O 3 : 0 to 0.5%.

6. 4. The optical glass according to claim 1, comprising the following components in weight percent and satisfying one or more of the following nine conditions: 1) B 2 EITHER 3 +To 2 EITHER 3 は0~6%; 2) Re 2 O 3 is 0-8%; 3) RO is 0-8%; 4) SiO 2 +ZrO 2 is 33-52%; 5) Nb 2 O 5 +ZrO 2 is 45-65%; 6) TiO 2 +WO 3 +Bi 2 O 3 is 0-7%; 7) Rn 2 O 10–18%; 8) (SiO 2 +ZrO 2 ) / Rn 2 O 1.8–6.5; 9) ZrO 2 / Rn 2 O is 0.2 to 1.8, The above-mentioned Re 2 O 3 La 2 O 3 , Gd 2 O 3 , Y 2 O 3 RO is the total content of BaO, SrO, CaO, and MgO, Rn 2 O is Li 2 O, Na 2 OK 2 The total O content.

7. 4. The optical glass according to claim 1, comprising the following components in % by weight: SiO 2 : 30 to 40%; and / or ZrO 2 : 4 to 10%; and / or Nb 2 O 5 : 41-54%; and / or B 2 O 3 : 0 to 3%; and / or Li 2 O: 3-6%; and / or Na 2 O: 5-12%; and / or K 2 O: 1-6%; and / or BaO: 0-2%; and / or CaO: 0-5%; and / or ZnO: 0-2%; and / or TiO 2 : 0 to 4%; and / or Sb 2 O 3 : 0 to 0.1%.

8. 4. An optical glass according to claim 1, comprising the following components in weight percent and satisfying one or more of the following seven conditions: 1) RO is 0-5%; 2) SiO 2 +ZrO 2 is 36-49%; 3) Nb 2 O 5 +ZrO 2 is 50-60%; 4) TiO 2 +WO 3 +Bi 2 O 3 is 0-4%; 5) Rn 2 O 12–16%; 6) (SiO 2 +ZrO 2 ) / Rn 2 O is 2.0-5.0; 7) ZrO 2 / Rn 2 O is 0.3 to 1.3, The RO is the total content of BaO, SrO, CaO, and MgO, and Rn 2 O is Li 2 O, Na 2 OK 2 The total O content.

9. The component is B 2 O 3 does not contain and / or Al 2 O 3 Does not contain and / or La 2 O 3 Does not contain and / or Gd 2 O 3 does not contain and / or Y 2 O 3 does not contain Yb 2 O 3 does not contain, and / or does not contain MgO, and / or does not contain SrO, and / or WO 3 does not contain and / or Bi 2 O 3 does not contain and / or Ta 2 O 5 does not contain and / or Re 2 O 3 does not include the Re 2 O 3 La 2 O 3 , Gd 2 O 3 , Y 2 O 3 The optical glass according to any one of claims 1 to 3, wherein the total content is

10. The refractive index n of the optical glass d is 1.74 to 1.82, and / or Abbe number ν d is 25-32, and / or relative partial dispersion P g,F ≦0.6497-0.001703×ν d and / or the λ of the optical glass 5 4. The optical glass according to claim 1, wherein the refractive index is 360 nm or less.

11. The refractive index n of the optical glass d is 1.76 to 1.80, and / or Abbe number ν d is 27-30, and / or relative partial dispersion P g,F ≦0.6477-0.001703×ν d and / or the λ of the optical glass 5 The optical glass according to any one of claims 1 to 3, wherein the refractive index is 350 nm or less.

12. A glass preform produced using the optical glass according to any one of claims 1 to 11.

13. An optical element produced using the optical glass according to any one of claims 1 to 11 or the glass preform according to claim 12.

14. An optical instrument comprising the optical glass according to any one of claims 1 to 11 and / or the optical element according to claim 13.

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