Optical glass, preparation method thereof and optical element

Abstract

The invention provides optical glass, a preparation method thereof and an optical element. The optical glass comprises the following components in percentage by mass: 1-12% of SiO2; 8 to 25 percent of B2O3; 0 to 0.7% of Li2O; 8 to 25 percent of ZnO; zrO2: 0 to 10%; 5% to 20% of Ta2O5; the sum of the contents of the La2O3, the Y2O3 and the Gd2O3 is 30%-55%, and the sum of the contents of the La2O3, the Y2O3 and the Gd2O3 is 30%-55%; the sum of the content of Nb2O5, the content of TiO2 and the content of WO3 is 0-10%, namely Nb2O5 + TiO2 + WO3. The optical glass provided by the invention has the advantages of high refraction, low dispersion and excellent coloring degree, can realize miniaturization and light weight of an optical system, has excellent mechanical properties and chemical stability, and is suitable for precise mold pressing formation.

Description

Technical Field

[0001] This invention relates to an optical glass, its preparation method, and optical elements, belonging to the field of optical glass. Background Technology

[0002] In recent years, the use of aspherical lenses in optical design has reduced the number of optical components, leading to a trend towards miniaturization and lightweight optical devices, and resulting in increasingly strong market demand. Refractive index n d The Abbe number is υ, ranging from 1.830 to 1.865. d Optical glass with a refractive index of 38-44 is widely used in automotive lenses, AR / VR technology, and mobile phone lenses due to its high refractive index and good transmittance. However, this type of optical glass generally has a high transition temperature (Tg) and sag temperature (Ts), resulting in high molding temperatures (generally exceeding 650℃) during precision molding, which easily leads to oxidation and corrosion on the surface of the molding die. In order to extend the life of the die and suppress the damage to the die caused by the high temperature environment, the molding temperature must be reduced. Therefore, the sag temperature (Ts) of the glass material used for molding needs to be as low as possible.

[0003] Patent application CN 114315130A discloses an optical glass that maintains a high refractive index while improving thermal stability and glass transition temperature characteristics, which is beneficial for precision glass molding. Its weight percentage composition contains: 2.5–12% SiO2; more than 0.7% Li2O; more than 6% ZnO; more than 25% La2O3; less than 17.5% Gd2O3; and more than 6% Ta2O5. The inclusion of a relatively large amount of Li2O in this patent application reduces the glass's devitrification resistance, and the high crystallization temperature and rapid crystallization rate during the molding process, along with the long high-temperature properties of the glass, make it difficult to eliminate defects such as internal bubbles and streaks, significantly increasing production difficulty and cost.

[0004] Patent application CN110963700A discloses a refractive index n d The Abbe number is υ, ranging from 1.84 to 1.87. d The optical glass has a density of 38-41 and exhibits good resistance to devitrification and crystallization. Its weight percentage composition includes: SiO2: 0-10%, B2O3: 5-25%, ZrO2: 0-15%, ZnO: 10-25%, TiO2+Nb2O5+WO3: 2-30%, and Ln2O3: 30-55%. The glass in this patent application has a high Ts (transformer saturation), which cannot meet the requirements of precision molding processes. Furthermore, the composition contains little or no Ta2O5, resulting in high dispersion, which makes it difficult to meet optical design requirements. Summary of the Invention

[0005] The problem the invention aims to solve

[0006] In view of the shortcomings of the prior art, the purpose of this invention is to provide an optical glass with a refractive index of 1.830 to 1.865 and an Abbe number of 38 to 44. The optical glass has a low transition temperature and sag temperature, and exhibits excellent resistance to crystallization, superior mechanical strength, and excellent colorimetric properties.

[0007] The present invention also provides a method for preparing optical glass, which is simple and easy to implement, uses readily available raw materials, and is suitable for mass production.

[0008] Solution for solving the problem

[0009] This invention provides an optical glass comprising, by weight percentage:

[0010] SiO2: 1-12%, preferably 1.5-11%, more preferably 2-10%;

[0011] B2O3: 8-25%, preferably 9-23%, more preferably 10-21%;

[0012] Li2O: 0-0.7%, preferably 0-0.6%, more preferably 0-0.5%;

[0013] ZnO: 8-25%, preferably 9-23%, more preferably 10-21%;

[0014] ZrO2: 0-10%, preferably 0-8%, more preferably 0-6%;

[0015] Ta2O5: 5-20%, preferably 6-19%, more preferably 7-18%; wherein...

[0016] The sum of the contents of La2O3, Y2O3 and Gd2O3, La2O3+Y2O3+Gd2O3, is 30-55%, preferably 33-52%, and more preferably 35-50%;

[0017] The sum of the contents of Nb2O5, TiO2, and WO3 (Nb2O5 + TiO2 + WO3) is 0–10%, preferably 0–9%, and more preferably 0–8%.

[0018] According to the optical glass of the present invention, wherein, by weight percentage,

[0019] The content of La2O3 is 25-45%, preferably 26-43%, and more preferably 27-41%;

[0020] The content of Y2O3 is 0-12%, preferably 0-11%, and more preferably 0-10%;

[0021] The content of Gd2O3 is 0-15%, preferably 0-12.5%, and more preferably 0-10%;

[0022] The Nb2O5 content is 0-5%, preferably 0-4.5%, and more preferably 0-4%.

[0023] The content of WO3 is 0-8%, preferably 0-7%, and more preferably 0-6%;

[0024] The TiO2 content is 0-3%, preferably 0-1.5%, and more preferably 0%.

[0025] According to the optical glass of the present invention, the content ratio of B2O3 to SiO2, B2O3 / SiO2, is 2.5 to 6, preferably 2.7 to 5.7, by weight percentage.

[0026] The ratio of the sum of ZnO and Li2O content to the sum of B2O3 and SiO2 content (ZnO+Li2O) / (SiO2+B2O3) is 0.9 to 1.5, preferably 0.92 to 1.47;

[0027] The ratio of Li2O to ZnO is 0 to 0.055, preferably 0.005 to 0.052.

[0028] According to the optical glass of the present invention, the ratio of the sum of the contents of ZrO2, Ta2O5, Nb2O5, WO3 and TiO2 to the sum of the contents of B2O3 and SiO2 (ZrO2+Ta2O5+Nb2O5+WO3+TiO2) / (SiO2+B2O3) is 0.8 to 1.5 by weight percentage, preferably 0.85 to 1.45;

[0029] The ratio of the sum of the contents of Li2O and ZnO to the sum of the contents of ZrO2, Ta2O5, Nb2O5, WO3 and TiO2 (ZnO+Li2O) / (ZrO2+Ta2O5+Nb2O5+TiO2+WO3) is 0.7 to 1.3, preferably 0.70 to 1.25;

[0030] The ratio of ZnO to WO3 is 3 to 8, preferably 3 to 7.

[0031] According to the optical glass of the present invention, the ratio of the content of WO3 to the sum of the contents of ZrO2, Ta2O5 and TiO2, WO3 / (ZrO2+Ta2O5+TiO2), is 0.15 to 0.5, preferably 0.15 to 0.47, by weight percentage.

[0032] The ratio of the content of La2O3 to the sum of the contents of La2O3, Y2O3 and Gd2O3, La2O3 / (La2O3+Y2O3+Gd2O3), is 0.62 to 0.85, preferably 0.64 to 0.83.

[0033] According to the optical glass of the present invention, the optical glass has a refractive index of 1.830 to 1.865 and an Abbe number of 38 to 44.

[0034] According to the optical glass of the present invention, the density of the optical glass is 5.4 g / cm³. 3 The following; and / or,

[0035] The tinting degree λ of the optical glass 70 / λ5 in λ 70 Below 380nm, λ5 is below 340nm; and / or,

[0036] The optical glass has a transition temperature Tg below 595°C and a sag temperature Ts below 630°C; and / or,

[0037] The liquidus temperature Lt of the optical glass is below 1120℃, and the devitrification resistance Tg / Lt is above 0.517.

[0038] According to the optical glass of the present invention, the hardness of the optical glass is 650 × 10⁻⁶. 7 Pa or higher, and Young's modulus is 115 GPa or higher; and / or,

[0039] The water resistance D of the optical glass W The optical glass has an acid resistance rating of D, which is classified as Grade 1. A Level 3 or above.

[0040] The present invention also provides a method for preparing optical glass according to the present invention, which includes: weighing each component in proportion, mixing them evenly, melting them, and then pouring or casting them into a molding die, or directly pressing them into shape.

[0041] The present invention also provides an optical element comprising the optical glass described in the present invention.

[0042] The effects of the invention

[0043] The optical glass of this invention has high refractive index, low dispersion, and excellent tinting strength, which can realize the miniaturization and weight reduction of optical systems. At the same time, the glass has excellent mechanical properties and chemical stability, and can be used in various environments.

[0044] The optical glass of the present invention has the advantages of low transition temperature and sag temperature and good anti-crystallization performance. After the sheet is reheated and softened, it is pressed or precision molded into optical elements of various shapes, and no crystallization or devitrification milky white phenomenon will occur in the glass.

[0045] In addition, the optical glass preparation method of the present invention has low production difficulty and manufacturing cost in each step, and is easy to achieve mass production. Detailed Implementation

[0046] Various exemplary embodiments, features, and aspects of the present invention will be described in detail below. The term "exemplary" as used herein means "serving as an example, embodiment, or illustration." Any embodiment described herein as "exemplary" is not necessarily to be construed as superior to or better than other embodiments.

[0047] Furthermore, to better illustrate the present invention, numerous specific details are set forth in the following detailed embodiments. Those skilled in the art should understand that the present invention can be practiced without certain specific details. In other instances, methods, means, apparatus, and steps well known to those skilled in the art have not been described in detail in order to highlight the spirit of the present invention.

[0048] Unless otherwise stated, all units used in this specification are international standard units, and all numerical values ​​and ranges appearing in this invention should be understood to include systematic errors that are unavoidable in industrial production.

[0049] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0050] In this specification, references to "some specific / preferred embodiments," "other specific / preferred embodiments," "implementation," etc., refer to specific elements (e.g., features, structures, properties, and / or characteristics) related to that embodiment, which are included in at least one of the embodiments described herein and may or may not be present in other embodiments. Furthermore, it should be understood that these elements may be combined in any suitable manner in various embodiments.

[0051] In this specification, the range of values ​​referred to as "value A to value B" refers to the range including the endpoint values ​​A and B.

[0052] In this specification, "not containing" and "0%" mean that the compound, element or other substance was not intentionally added to the glass of this invention as a raw material. However, as raw materials and / or equipment for producing glass, there may be some impurities or components that are not intentionally added, which are present in small or trace amounts in the final glass. Such cases are also within the scope of protection of this patent.

[0053] This invention provides an optical glass comprising, by weight percentage:

[0054] SiO2: 1-12%, preferably 1.5-11%, more preferably 2-10%;

[0055] B2O3: 8-25%, preferably 9-23%, more preferably 10-21%;

[0056] Li2O: 0-0.7%, preferably 0-0.6%, more preferably 0-0.5%;

[0057] ZnO: 8-25%, preferably 9-23%, more preferably 10-21%;

[0058] ZrO2: 0-10%, preferably 0-8%, more preferably 0-6%;

[0059] Ta2O5: 5-20%, preferably 6-19%, more preferably 7-18%;

[0060] The sum of the contents of La2O3, Y2O3 and Gd2O3, La2O3+Y2O3+Gd2O3, is 30-55%, preferably 33-52%, and more preferably 35-50%;

[0061] The sum of the contents of Nb2O5, TiO2, and WO3 (Nb2O5 + TiO2 + WO3) is 0–10%, preferably 0–9%, and more preferably 0–8%.

[0062] In this invention, the optical glass has a refractive index of 1.830 to 1.865 and an Abbe number of 38 to 44.

[0063] The optical glass of this invention features high refractive index, low dispersion, and excellent tinting strength, enabling miniaturization and weight reduction of optical systems. Simultaneously, the glass exhibits excellent mechanical properties and chemical stability, allowing it to be used in various environments. Furthermore, the optical glass of this invention has advantages such as low transition temperature and sag temperature, and good resistance to crystallization. Even after the sheet material is reheated and softened, and then re-formed or precision-molded into optical elements of various shapes, no crystallization or devitrification / milky white phenomenon occurs within the glass.

[0064] The raw material introduction method adopts various forms of compounds that can introduce their corresponding content, such as carbonates, nitrates, oxides, sulfates, hydroxides, etc.

[0065] SiO2 is a network-forming component in glass, which can improve the chemical stability, transparency, and mechanical strength of glass, as well as its resistance to devitrification. If the SiO2 content is higher than 12%, the glass transition temperature (Tg) and relaxation temperature (Ts) will increase significantly, and it will be difficult to achieve the required refractive index. If the SiO2 content is lower than 1%, the glass's resistance to devitrification deteriorates, and its chemical stability and mechanical strength decrease. Therefore, the SiO2 content is controlled between 1% and 12%, preferably 1.5% to 11%, more preferably 2% to 10%, for example: 2.5%, 3.5%, 4.5%, 5.5%, 6.5%, 7.5%, 8.5%, 9.5%, etc.

[0066] B2O3 is a component of the glass network forging system, which can improve the melt properties of glass and lower the transition temperature and sag temperature. When an appropriate amount of B2O3 is present in the glass, it can increase the strength of the glass network, improving its devitrification resistance and chemical stability. However, if the B2O3 content exceeds 25%, it will damage the network structure, causing a decrease in the glass's devitrification resistance, chemical stability, and mechanical properties. If the B2O3 content is below 8%, the glass's transition temperature and sag temperature are difficult to meet requirements. Therefore, the B2O3 content is controlled between 8% and 25%, preferably 9% to 23%, more preferably 10% to 21%, for example: 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, etc.

[0067] In this invention, if the B2O3 / SiO2 ratio is too high, the optical glass crystallization rate is too fast and difficult to control. If the B2O3 / SiO2 ratio is too low, the optical glass transition temperature and sag temperature will not meet the design requirements. Therefore, in this invention, the B2O3 / SiO2 content is controlled at 2.5–6, preferably 2.7–5.7, more preferably 2.8–5.5, for example: 3, 3.5, 4, 4.5, 5, 5.5, etc.

[0068] Adding rare earth oxides (La₂O₃, Y₂O₃, or Gd₂O₃) to glass helps to improve its refractive index. When the sum of the contents of La₂O₃, Y₂O₃, and Gd₂O₃ (La₂O₃ + Y₂O₃ + Gd₂O₃) is less than 30%, the desired optical constants cannot be obtained. However, when the sum of the contents of La₂O₃, Y₂O₃, and Gd₂O₃ (La₂O₃ + Y₂O₃ + Gd₂O₃) is greater than 55%, the chemical stability and devitrification resistance of the glass will decrease. Therefore, in this invention, the content of La₂O₃ + Y₂O₃ + Gd₂O₃ is controlled at 30-55%, preferably 33-52%, more preferably 35-50%, for example: 38%, 40%, 42%, 44%, 46%, 48%, etc.

[0069] La₂O₃ is a high-refractive-index, low-dispersion oxide that acts as a network in glass, increasing its refractive index and maintaining low dispersion. If the La₂O₃ content is too high, the glass's thermal stability and devitrification resistance decrease, and the glass transition temperature tends to increase. If the La₂O₃ content is too low, the glass refractive index will not meet requirements. Therefore, the La₂O₃ content is controlled between 25% and 45%, preferably 26% to 43%, more preferably 27% to 41%, for example: 28%, 30%, 32%, 34%, 36%, 38%, 40%, etc.

[0070] Y₂O₃ can maintain a high refractive index and a high Abbe number, control the cost of glass materials, and improve the meltability and devitrification resistance of glass. It can also lower the upper limit temperature of glass crystallization. However, if its content is too high, the chemical stability and devitrification resistance of the glass will decrease. Therefore, the Y₂O₃ content is controlled at 0-12%, preferably 0-11%, more preferably 0-10%, for example: 1%, 2%, 4%, 6%, 8%, 9%, etc.

[0071] Gd₂O₃ can increase the refractive index of glass without significantly improving its dispersion. In this invention, the introduction of Gd₂O₃ improves the stability of glass formation and significantly enhances its chemical stability. However, if its content exceeds 15%, the glass's devitrification resistance decreases. Therefore, the Gd₂O₃ content is controlled between 0 and 15%, preferably between 0 and 12.5%, and more preferably between 0 and 10%, for example: 1%, 2%, 4%, 6%, 8%, 9%, etc.

[0072] In this invention, if the ratio of the La2O3 content to the sum of the contents of La2O3, Y2O3, and Gd2O3 (La2O3 / (La2O3+Y2O3+Gd2O3)) is too high, the dispersion and tinting strength of the optical glass will be severely deteriorated. If the ratio is too low, the anti-crystallization performance of the optical glass will decrease. Therefore, in this invention, the ratio of La2O3 / (La2O3+Y2O3+Gd2O3) is controlled at 0.62–0.85, preferably 0.64–0.83, more preferably 0.66–0.81, for example: 0.68, 0.70, 0.72, 0.74, 0.76, 0.78, 0.80, etc.

[0073] Li₂O is an outer layer of the glass network, which can lower the glass transition temperature, relaxation temperature, and improve glass melt properties, but Li + Li₂O has strong polarization ability. When the Li₂O content is higher than 0.7%, it easily leads to severe glass crystallization, with a fast crystallization rate and a high upper limit for crystallization temperature, increasing production difficulty. Simultaneously, the low viscosity of the glass during melting easily causes flash point defects within the glass, and the long glass stretching during forming easily results in internal streaks, leading to a low overall glass yield and high production costs. Therefore, the Li₂O content of this invention is 0–0.7%, preferably 0–0.6%, more preferably 0–0.5%, for example: 0.1%, 0.2%, 0.3%, 0.4%, etc.

[0074] ZnO is an effective component for lowering the melting temperature, liquidus temperature, transition temperature, and sag temperature of glass. It also improves the chemical stability of glass, enhances the light transmittance of optical glass, and inhibits the decrease in refractive index. If the ZnO content is higher than 25%, the glass's resistance to devitrification deteriorates, and defects such as flash points, streaks, and bubbles are more likely to occur during glass manufacturing. If the ZnO content is lower than 8%, the sag temperature and transition temperature of the glass do not meet design requirements. Therefore, in this invention, the ZnO content is controlled at 8–25%, preferably 9–23%, more preferably 10–21%, for example: 11%, 13%, 15%, 17%, 19%, 20%, etc.

[0075] Zn 2+ Li + Both possess strong polarization capabilities, and in glass, they can weaken the Si-O network structure, lower the glass transition temperature and relaxation temperature, while Zn... 2+ Li + The presence of aggregates can enhance the chemical stability and improve the transmittance of glass when introduced in appropriate amounts. In this invention, if the ratio of the sum of ZnO and Li2O content to the sum of B2O3 and SiO2 content (ZnO+Li2O) / (SiO2+B2O3) is too high, the devitrification resistance of the optical glass will decrease sharply, and the chemical stability of the glass will be poor. If the ratio of the sum of ZnO and Li2O content to the sum of B2O3 and SiO2 content (ZnO+Li2O) / (SiO2+B2O3) is too low, the transition temperature and sag temperature of the optical glass will not meet the design requirements. Therefore, in this invention, ∑(ZnO+Li2O) / ∑(SiO2+B2O3) can be controlled between 0.9 and 1.5, preferably between 0.92 and 1.47, more preferably between 0.92 and 1.45, for example 0.95, 1.0, 1.05, 1.1, 1.15, 1.2, 1.25, 1.3, 1.35, 1.4, etc.

[0076] Li + Commonly used as a nucleating agent introduced into glass. The inventors of this invention discovered that the content ratio of Li₂O to ZnO (Li₂O / ZnO) needs to be controlled. If the Li₂O / ZnO ratio is too high, the glass's resistance to devitrification decreases, and the crystallization rate is rapid, greatly increasing the difficulty of production. Therefore, in this invention, the Li₂O / ZnO ratio is controlled at 0–0.055, preferably 0.005–0.052, more preferably 0.01–0.05, for example 0.015, 0.02, 0.025, 0.03, 0.035, 0.04, 0.045, etc.

[0077] ZrO2 is an effective component for improving the refractive index and hardness of optical glass, and it also significantly increases the glass forming viscosity and improves chemical stability. If the ZrO2 content exceeds 10%, the glass's melting performance deteriorates, the melting temperature increases, and the glass's devitrification resistance decreases. Therefore, in this invention, the ZrO2 content is controlled at 0–10%, preferably 0–8%, more preferably 0–6%, for example: 1%, 2%, 3%, 4%, 5%, 7%, 9%, etc.

[0078] Ta₂O₅ is an important component for maintaining the high refractive index, low dispersion, and thermal stability of glass. If the Ta₂O₅ content is less than 5%, the design requirements will not be met. If the Ta₂O₅ content is higher than 20%, the glass's devitrification resistance will decrease, and the raw material cost will be too high. Therefore, in this invention, the Ta₂O₅ content is controlled at 5-20%, preferably 6-19%, more preferably 7-18%, for example: 8%, 10%, 12%, 14%, 16%, etc.

[0079] Nb₂O₅, TiO₂, and WO₃ are high-refractive-index, high-dispersion oxides that help improve the refractive index of glass. In this invention, if the sum of the contents of Nb₂O₅, TiO₂, and WO₃ (Nb₂O₅ + TiO₂ + WO₃) exceeds 10%, the glass dispersion is too high, making it difficult to achieve the corresponding optical properties, and the glass transmittance will also deteriorate. Therefore, in this invention, Nb₂O₅ + TiO₂ + WO₃ is controlled at 0–10%, preferably 0–9%, more preferably 0–8%, for example: 1%, 2%, 3%, 4%, 5%, 6%, 7%, etc.

[0080] Nb₂O₅ improves the thermal stability and increases the refractive index of glass. However, if the Nb₂O₅ content is too high, the optical properties of the glass will not meet design requirements. Therefore, the Nb₂O₅ content is controlled between 0% and 5%, preferably 0% to 4.5%, and more preferably 0% to 4%, for example: 0%, 0.5%, 1%, 2%, 3%, etc.

[0081] WO3 can maintain optical constants and improve the crystallization performance of glass, but if its content is too high, it will reduce the transmittance of glass and worsen the crystallization performance. Therefore, in this invention, the WO3 content is controlled at 0-8%, preferably 0-7%, more preferably 0-6%, for example: 0%, 1%, 2%, 3%, 4%, 5%, etc.

[0082] In this invention, if the ZnO / WO3 content ratio (ZnO / WO3) is too high by weight percentage, the glass exhibits poor chemical stability and a low refractive index that fails to meet design requirements. Conversely, if the ZnO / WO3 content ratio is too low, the glass exhibits poor colorimetry, high dispersion, and a higher crystallization limit, increasing the difficulty of glass production. Therefore, in this invention, the ZnO / WO3 ratio is controlled at 3–8, preferably 3–7, and more preferably 3–6.5, such as 3.5, 4.0, 4.5, 5.0, 5.5, and 6.0.

[0083] TiO2 can increase the refractive index of glass and improve its crystallization properties, but excessive TiO2 content can lead to a decrease in glass colorability and a deterioration in crystallization properties. Therefore, in this invention, the TiO2 content is controlled at 0-3%, preferably 0-1.5%, and more preferably 0%.

[0084] Zr 4+ Ta 5+ and Ti 4+ All of these components possess high ion field strength and strong aggregation ability within glass. The inventors of this invention discovered that if the ratio of WO3 content to the sum of ZrO2, Ta2O5, and TiO2 content (WO3 / (ZrO2+Ta2O5+TiO2)) is too high, the optical properties of the glass will not meet design requirements; conversely, if the ratio is too low, the glass will have poor devitrification resistance. Therefore, in this invention, WO3 / ∑(ZrO2+Ta2O5+TiO2) is 0.15–0.5, preferably 0.15–0.47, more preferably 0.15–0.45, for example, 0.2, 0.25, 0.3, 0.35, 0.4, etc.

[0085] In this invention, if the ratio of the sum of the contents of ZrO2, Ta2O5, Nb2O5, WO3, and TiO2 to the sum of the contents of B2O3 and SiO2 (ZrO2+Ta2O5+Nb2O5+WO3+TiO2) / (SiO2+B2O3) is too high by weight percentage, the anti-crystallization performance of the optical glass will decrease significantly; if the ratio of the sum of the contents of ZrO2, Ta2O5, Nb2O5, WO3, and TiO2 to the sum of the contents of B2O3 and SiO2 (ZrO2+Ta2O5+Nb2O5+WO3+TiO2) / (SiO2+B2O3) is too low, the optical performance of the optical glass will not meet the design requirements. Therefore, in this invention, ∑(ZrO2+Ta2O5+Nb2O5+WO3+TiO2) / ∑(SiO2+B2O3) can be controlled between 0.8 and 1.5, preferably between 0.85 and 1.45, more preferably between 0.9 and 1.4, for example 0.95, 1.0, 1.05, 1.10, 1.15, 1.20, 1.25, 1.3, 1.35, etc.

[0086] In this invention, if the ratio of the sum of the contents of Li2O and ZnO to the sum of the contents of ZrO2, Ta2O5, Nb2O5, WO3 and TiO2 (ZnO+Li2O) / (ZrO2+Ta2O5+Nb2O5+TiO2+WO3) is too high by weight percentage, the optical performance of the optical glass will not meet the design requirements. If the ratio of the sum of the contents of Li2O and ZnO to the sum of the contents of ZrO2, Ta2O5, Nb2O5, WO3 and TiO2 (ZnO+Li2O) / (ZrO2+Ta2O5+Nb2O5+TiO2+WO3) is too low, the transition temperature and sag temperature of the optical glass will not meet the requirements, and the melting temperature of the glass will be too high, which may increase the risk of platinum flash point during the melting process. Therefore, (ZnO+Li2O) / (ZrO2+Ta2O5+Nb2O5+WO3+TiO2) can be controlled within the range of 0.7 to 1.30, preferably 0.7 to 1.25, more preferably 0.7 to 1.2, such as 0.75, 0.8, 0.85, 0.9, 0.95, 1.0, 1.05, 1.1, 1.15, etc.

[0087] In this invention, the density of the optical glass is 5.4 g / cm³. 3 The following describes the tinting degree λ of the optical glass. 70 / λ5 in λ 70 The wavelength is below 380 nm, and λ5 is below 340 nm; the transition temperature Tg of the optical glass is below 595℃, and the sag temperature Ts is below 630℃. The liquidus temperature Lt of the optical glass is below 1120℃, and the devitrification resistance Tg / Lt is above 0.517.

[0088] In this invention, the hardness of the optical glass is 650 × 10⁻⁶. 7 The optical glass has a water resistance of ≥115 GPa and a Young's modulus of ≥115 GPa; W Grade 1; the acid resistance D of the optical glass. A Level 3 or above, such as Level 3, Level 2, Level 1, etc.

[0089] This invention also provides a method for preparing optical glass according to the present invention, comprising the steps of converting the components of the optical glass into corresponding raw materials such as carbonates, nitrates, sulfates, hydroxides, and oxides according to a certain proportion, and weighing and mixing the corresponding raw materials. The resulting batch is then melted, stirred, clarified, and homogenized, and subsequently poured or cast into a molding die, or directly blown or pressed to obtain optical glass sheets or optical element blanks. The resulting optical glass is high-quality optical glass with few or no bubbles and few or no streaks.

[0090] According to the method for preparing optical glass of the present invention, in a preferred embodiment, it specifically includes: weighing and mixing the raw materials of each component in proportion to form a batch, and putting the batch into a corrosion-resistant crucible such as platinum, quartz or alumina, melting it at a temperature of 1100℃~1200℃, homogenizing it for 2~6 hours, clarifying it at a temperature of 1300~1400℃ for 2~6 hours to allow the bubbles to rise fully, then lowering the temperature of the glass melt to about 1200~1300℃, holding it at that temperature for 0.1~1 hour, pouring it into a molding die or leaking it through a cylindrical pipe, and after annealing and cooling, processing it to obtain the optical glass of the present invention.

[0091] The present invention also provides an optical element comprising the optical glass according to the present invention. The optical glass of the present invention can be used to fabricate optical elements, i.e., glass elements or optical preforms, i.e., glass preforms.

[0092] Specifically, the present invention can use methods such as grinding, hot pressing, or precision stamping to manufacture glass preforms. That is, glass preforms can be manufactured by machining the glass, such as grinding and polishing; or by making a preform from glass for molding, then hot pressing and grinding the preform; or by precision stamping a preform made through grinding. It should be noted that the means of preparing glass preforms are not limited to the above-mentioned methods.

[0093] Example

[0094] The embodiments of the present invention will be described in detail below with reference to examples. However, those skilled in the art will understand that the following examples are for illustrative purposes only and should not be considered as limiting the scope of the invention. Unless otherwise specified in the examples, conventional conditions or conditions recommended by the manufacturer are followed. Reagents or instruments whose manufacturers are not specified are all commercially available conventional products.

[0095] Examples 1-40

[0096] The components of Examples 1 to 40 in Tables 1 to 5 are weighed and mixed evenly to prepare a batch. The batch is then placed in a crucible made of precious metal Pt and melted at a temperature of about 1150°C for about 4 hours. After homogenization, the temperature is raised to about 1350°C for about 4 hours for clarification. The temperature is then lowered to about 1250°C and held for 0.5 hours before being removed from the furnace and poured into a mold to form the glass. After annealing and cooling, the optical glass of this application can be obtained.

[0097] Comparative examples A and B

[0098] The raw materials corresponding to the components in Table 6 below were weighed according to the specified proportions and prepared using the same preparation method as in Examples 1 to 40 to obtain optical glasses for Comparative Examples A and B.

[0099] Performance testing

[0100] 1. Refractive index n d Abbe number υ d

[0101] The refractive index n of the obtained optical glass was determined according to the test method of GB / T 7962.1-2010. d Abbe number υ d The determination of n listed in the table d υ d The data is for annealing at ~30℃ / H.

[0102] 2. Density

[0103] The density ρ of the obtained optical glass was determined according to the test method of GB / T 7962.20-2010.

[0104] 3. Transition temperature Tg, sag temperature Ts

[0105] The transition temperature Tg and sag temperature Ts of the obtained optical glass were determined according to the test method of GB / T7962.16-2010.

[0106] 4. Shading degree λ 70 / λ5

[0107] The tinting λ of optical glass was tested according to the test method of GB / T 903-2019. 70 / λ5, where λ 70 λ1 represents the wavelength corresponding to a transmittance of 70%, and λ2 represents the wavelength corresponding to a transmittance of 5%.

[0108] 5. Lt is the liquidus temperature.

[0109] The upper limit of crystallization temperature is Lt, which is measured using the DTA (Differential Thermal Analysis) method. The temperature corresponding to the highest thermal absorption peak in the DTA curve is Lt.

[0110] 6. Hardness HK

[0111] The hardness of the obtained optical glass was measured according to the test method of GB / T 7962.18-2010.

[0112] 7. Young's modulus E

[0113] The Young's modulus E of optical glass shall be tested according to the method specified in GB / T 7962.6.

[0114] 8. Water resistance D W Acid resistance D A

[0115] The water resistance of the obtained optical glass was tested according to the test method of GB / T 17129. W Acid resistance D A Conduct the test.

[0116] The refractive index n of the optical glasses prepared in Examples 1-40 and Comparative Example AB d Abbe number υ d Density ρ, Transition temperature Tg, Sagging temperature Ts, Colorimetric λ 70 / λ5, Liquidation temperature Lt, Resistance to loss of charge Tg / Lt, Hardness HK, Young's modulus E, Water resistance D W Acid resistance D A The following are listed in Tables 1-6.

[0117] Table 1

[0118]

[0119] Table 2

[0120]

[0121] Table 3

[0122]

[0123] Table 4

[0124]

[0125] Table 5

[0126]

[0127] Table 6: Glass composition and performance parameters of comparative examples A to B

[0128]

[0129] As can be seen from Tables 1-5, the optical glasses of Examples 1-40 of the present invention not only have a high refractive index (n) d ), High Abbe number (υ) d Furthermore, the glass has a transition temperature (Tg) below 595℃ and a sag temperature (Ts) below 630℃, making it suitable for precision molding. At the same time, the glass has good transmittance, mechanical properties, and chemical stability. In addition, the glass has good resistance to crystallization, making it suitable for large-scale mass production.

[0130] As shown in Table 6, in Examples A and B, the ratio of ZnO to WO3 (ZnO / WO3) is less than 3, resulting in poorer glass coloration and a higher upper limit for crystallization, which increases the difficulty of glass production. The ratio of the sum of ZnO and Li2O content to the sum of B2O3 and SiO2 content (Li2O+ZnO) / (SiO2+B2O3) is less than 0.9, resulting in higher Tg and Ts of the glass, which is not conducive to precision glass molding.

[0131] It should be noted that although the technical solution of the present invention has been described with specific examples, those skilled in the art will understand that the present invention should not be limited thereto.

[0132] The various embodiments of the present invention have been described above. These descriptions are exemplary and not exhaustive, nor are they limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the scope and spirit of the described embodiments. The terminology used herein is chosen to best explain the principles, practical application, or technical improvements to the embodiments in the market, or to enable others skilled in the art to understand the embodiments disclosed herein.

Claims

1. An optical glass, characterized in that, It comprises the following components by weight percentage: SiO2: 1-12%, preferably 1.5-11%, more preferably 2-10%; B2O3: 8-25%, preferably 9-23%, more preferably 10-21%; Li2O: 0-0.7%, preferably 0-0.6%, more preferably 0-0.5%; ZnO: 8-25%, preferably 9-23%, more preferably 10-21%; ZrO2: 0-10%, preferably 0-8%, more preferably 0-6%; Ta2O5: 5-20%, preferably 6-19%, more preferably 7-18%; The sum of the contents of La2O3, Y2O3 and Gd2O3, La2O3+Y2O3+Gd2O3, is 30-55%, preferably 33-52%, and more preferably 35-50%; The sum of the contents of Nb2O5, TiO2, and WO3 (Nb2O5 + TiO2 + WO3) is 0–10%, preferably 0–9%, and more preferably 0–8%.

2. The optical glass according to claim 1, characterized in that, By weight percentage, The content of La2O3 is 25-45%, preferably 26-43%, and more preferably 27-41%; The content of Y2O3 is 0-12%, preferably 0-11%, and more preferably 0-10%; The content of Gd2O3 is 0-15%, preferably 0-12.5%, and more preferably 0-10%; The Nb2O5 content is 0-5%, preferably 0-4.5%, and more preferably 0-4%. The content of WO3 is 0-8%, preferably 0-7%, and more preferably 0-6%; The TiO2 content is 0-3%, preferably 0-1.5%, and more preferably 0%.

3. The optical glass according to claim 1 or 2, characterized in that, The content ratio of B2O3 to SiO2, by weight percentage, is 2.5 to 6, preferably 2.7 to 5.

7. The ratio of the sum of ZnO and Li2O content to the sum of B2O3 and SiO2 content (ZnO+Li2O) / (SiO2+B2O3) is 0.9 to 1.5, preferably 0.92 to 1.47; The ratio of Li2O to ZnO is 0 to 0.055, preferably 0.005 to 0.

052.

4. The optical glass according to any one of claims 1 to 3, characterized in that, The ratio of the sum of the contents of ZrO2, Ta2O5, Nb2O5, WO3 and TiO2 to the sum of the contents of B2O3 and SiO2 (ZrO2+Ta2O5+Nb2O5+WO3+TiO2) / (SiO2+B2O3) is 0.8 to 1.5 by weight percentage, preferably 0.85 to 1.

45. The ratio of the sum of the contents of Li2O and ZnO to the sum of the contents of ZrO2, Ta2O5, Nb2O5, WO3 and TiO2 (ZnO+Li2O) / (ZrO2+Ta2O5+Nb2O5+TiO2+WO3) is 0.7 to 1.3, preferably 0.70 to 1.25; The ratio of ZnO to WO3 is 3 to 8, preferably 3 to 7.

5. The optical glass according to any one of claims 1 to 4, characterized in that, The ratio of WO3 content to the sum of ZrO2, Ta2O5 and TiO2 content, WO3 / (ZrO2+Ta2O5+TiO2), is 0.15 to 0.5 by weight percentage, preferably 0.15 to 0.

47. The ratio of the content of La2O3 to the sum of the contents of La2O3, Y2O3 and Gd2O3, La2O3 / (La2O3+Y2O3+Gd2O3), is 0.62 to 0.85, preferably 0.64 to 0.

83.

6. The optical glass according to any one of claims 1 to 5, characterized in that, The optical glass has a refractive index of 1.830–1.865 and an Abbe number of 38–44.

7. The optical glass according to any one of claims 1 to 6, characterized in that, The density of the optical glass is 5.4 g / cm³. 3 The following; and / or, The tinting degree λ of the optical glass 70 / λ5 in λ 70 For wavelengths below 380nm, λ5 is below 340nm; and / or, The optical glass has a transition temperature Tg below 595°C and a sag temperature Ts below 630°C; and / or, The liquidus temperature Lt of the optical glass is below 1120℃, and the devitrification resistance Tg / Lt is above 0.

517.

8. The optical glass according to any one of claims 1 to 7, characterized in that, The hardness of the optical glass is 650 × 10⁻⁶. 7 Pa or higher, Young's modulus 115 GPa or higher; and / or, The water resistance D of the optical glass W The optical glass has an acid resistance rating of D, which is classified as Grade 1. A Level 3 or above.

9. A method for preparing optical glass according to any one of claims 1 to 8, characterized in that, include: The components are weighed and mixed evenly according to the proportions, then melted and poured or poured into the molding mold, or directly pressed into shape.

10. An optical element, characterized in that, Includes the optical glass according to any one of claims 1 to 8.

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