Lanthanum flint optical glass, its preparation method and optical components

Abstract

This invention provides a lanthanum flint optical glass comprising the following components in molar percentage of cations: Si 4+ 20-40%; B 3+ : 0-25%; La 3+ 0-5%; Zn 2+ 0-10%; Zr 4+ 0-5%; Ti 4+ 6-16%; Nb 5+ 0-3%; Ba 2+ : 0-18%; Sr 2+ : 0-10%; Na + 5-20%; Sb 3+ The lanthanum flint optical glass has a refractive index of 1.710-1.783 and an Abbe number of 32.0-38.2. The lanthanum flint optical glass of this invention has low transition temperature and relaxation temperature, a small coefficient of linear expansion, low density, high hardness, suitable abrasion resistance, low tinting strength, and excellent devitrification resistance, chemical stability, and mechanical properties, making it easy to mass-produce.

Description

Technical Field

[0001] This invention relates to an environmentally friendly lanthanum flint optical glass, its preparation method, and optical components, belonging to the field of optical glass technology. Background Technology

[0002] Glass with a refractive index of 1.710-1.783 and an Abbe number of 32.0-38.2 is generally produced using a borosilicate system, with the addition of Nb₂O₅ and alkaline earth metals, and is mainly used in cameras, optical communications, and smart home applications. In recent years, due to increasingly fierce market competition and rising cost pressures, the market trend has shifted towards lower cost and higher performance. Currently, this type of glass uses a high content of Nb₂O₅ and La₂O₃, resulting in high density and cost, which limits its applications. Therefore, there is a need to develop glass with a higher cost-performance ratio to meet market demands.

[0003] Patent applications CN110482854A, CN110937802A, CN112424135A, and CN110234612A contain large amounts of alkaline earth metals or rare earth elements. These materials not only have high density but are also susceptible to increases in rare earth prices, leading to higher costs. Furthermore, since alkaline earth metals and rare earth elements are network components, they can impair the crystallization properties and chemical stability of optical glass.

[0004] Patent applications CN113292242A and CN114163122A contain large amounts of Nb2O5, while CN114315131A contains large amounts of Gd2O3, resulting in high costs that do not align with the market trend towards low-cost solutions. From a cost-performance perspective, these should be avoided.

[0005] Patent application CN115321812A, for example, contains a large amount of ZnO, which can lead to a decrease in the chemical stability and crystallization properties of the glass. From the perspective of chemical stability, it is best to introduce as little ZnO as possible or not at all.

[0006] Patent application CN1446762A and others contain a large amount of P2O5. Phosphate glasses easily corrode precious metal containers such as platinum, especially phosphate glasses containing alkali metals, which are even more corrosive. Furthermore, P is prone to volatilization at high temperatures, affecting the optical stability of the glass. Summary of the Invention

[0007] The problem the invention aims to solve

[0008] In view of the technical problems existing in the prior art, the present invention first provides a refractive index n d The Abbe number is υ, which ranges from 1.710 to 1.783. dThe lanthanum flint optical glass is environmentally friendly and cost-effective, with a thickness of 32.0-38.2. It features low transition and relaxation temperatures, a small coefficient of linear expansion, low density, high hardness, suitable abrasion resistance, low tinting strength, and excellent devitrification resistance, chemical stability, and mechanical properties, making it easy to mass-produce.

[0009] Furthermore, the present invention also provides a method for preparing lanthanum flint optical glass, which is simple and easy to implement, uses readily available raw materials, and is suitable for mass production.

[0010] Solution for solving the problem

[0011] This invention provides a lanthanum flint optical glass comprising the following components in molar percentage of cations:

[0012] Si 4+ : 20-40%, preferably 22-35%;

[0013] B 3+ : 0-25%, preferably 5-22%;

[0014] La 3+ 0-5%, preferably 1-4%;

[0015] Zn 2+ : 0-10%, preferably 3-8%;

[0016] Zr 4+ 0-5%, preferably 2-4%;

[0017] Ti 4+ : 6-16%, preferably 8-13%;

[0018] Nb 5+ 0-3%, preferably 1-2%;

[0019] Ba 2+ : 0-18%, preferably 3-15%;

[0020] Sr 2+ : 0-10%, preferably 5-8%;

[0021] Na + 5-20%, preferably 10-15%;

[0022] Sb 3+ : 0-0.1%, preferably 0-0.05%;

[0023] The refractive index of the lanthanum flint optical glass is 1.710-1.783; the Abbe number is 32.0-38.2.

[0024] According to the lanthanum flint optical glass of the present invention, wherein, in terms of cation molar percentage, Si 4+ With B 3+ The sum ∑ Si 4+ +B 3+ The content is 33-54%, preferably 40-50%;

[0025] B 3+ With Si 4+ The ratio of B 3+ / Si 4+ The value is 0-1.2, preferably 0.3-0.9;

[0026] Si 4+ B 3+ With Ti 4+ The sum ∑ Si 4+ +B 3+ +Ti 4+ The content is 40-65%, preferably 45-60%;

[0027] Si 4+ B 3+ Ti 4+ Zn 2+ With Zr 4+ The sum ∑ Si 4+ +B 3+ +Ti 4+ +Zn 2+ +Zr 4+ The percentage is 53-74%, with 58-70% being preferred.

[0028] According to the lanthanum flint optical glass of the present invention, wherein, based on the molar percentage of cations, Ba 2+ With Sr 2+ The sum ∑Ba 2+ +Sr 2+ The percentage is 8-28%, preferably 10-22%;

[0029] Ba 2+ 、Sr 2+ With Zn 2+ The sum ∑Ba 2+ +Sr 2+ +Zn 2+ The percentage is 15-36%, preferably 17-30%;

[0030] Ba 2+ 、Sr 2+ with Na + The sum ∑Ba 2+ +Sr 2+ +Na + The percentage is 20-44%, with 22-40% being preferred.

[0031] According to the lanthanum flint optical glass of the present invention, wherein, based on the molar percentage of cations, Zn 2+ Ba 2+ With Sr 2 + The sum of and B 3+ With Ti 4+ The ratio of the sums (Zn) 2+ +Ba 2+ +Sr 2+ ) / (Ti 4+ +B 3+ The value is 0-2.5, preferably 0.3-2;

[0032] Zn 2+ Ba 2+ With Sr 2+ The sum of Ti 4+ B 3+ With Zr 4+ The ratio of the sums (Zn) 2+ +Ba 2+ +Sr 2+ ) / (Ti 4+ +B 3+ +Zr 4+ The value is 0-2.1, preferably 0.3-1.7;

[0033] Ba 2+ 、Sr 2+ with Na + The sum of Ti 4+ B 3+ Zn 2+ With Zr 4+ The ratio of the sums (Ba) 2+ +Sr 2+ +Na + ) / (Ti 4+ +B 3+ +Zn 2+ +Zr 4+ The ratio of ) is 0-2, preferably 0.3-1.5.

[0034] According to the lanthanum flint optical glass of the present invention, wherein, based on the molar percentage of cations, Nb 5+ With Ti 4+ The ratio of Nb 5+ / Ti 4+ The value is 0-0.5, preferably 0.1-0.3.

[0035] According to the lanthanum flint optical glass of the present invention, the linear expansion coefficient α of the lanthanum flint optical glass is... -50 / 80℃ Not exceeding 82×10 -7 / ℃;

[0036] The lanthanum flint optical glass has a transition temperature Tg not exceeding 580℃, a sag temperature Ts not exceeding 630℃, and a liquidus temperature L... T Not exceeding 1000℃;

[0037] The tinting λ of the lanthanum flint optical glass 80 λ in / λ5 80 Below 415nm, λ5 is below 355nm.

[0038] According to the lanthanum flint optical glass of the present invention, the hardness of the lanthanum flint optical glass is not less than 550 × 10⁻⁶. 7 Pa;

[0039] The abrasion resistance of the lanthanum flint optical glass is 80-150.

[0040] The density of the lanthanum flint optical glass does not exceed 3.85 g / cm³. 3 .

[0041] According to the lanthanum flint optical glass of the present invention, the lanthanum flint optical glass has a moisture resistance, water resistance, alkali resistance and washing resistance of grade 1.

[0042] The lanthanum flint optical glass has an acid resistance stability of level 2 or above.

[0043] The present invention also provides a method for preparing lanthanum flint 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.

[0044] The present invention also provides an optical element comprising the lanthanum flint optical glass according to the present invention.

[0045] The effects of the invention

[0046] The lanthanum flint optical glass of the present invention has a low transition temperature and sag temperature, a small linear expansion coefficient, low density, high hardness, suitable abrasion resistance, low colorimetric properties, and excellent devitrification resistance, chemical stability and mechanical properties, making it easy to achieve mass production.

[0047] Furthermore, the preparation method of the lanthanum flint optical glass of the present invention is simple and easy to implement, the raw materials are readily available, and it is suitable for mass production. Detailed Implementation

[0048] 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.

[0049] 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.

[0050] 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.

[0051] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0052] 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.

[0053] 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.

[0054] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be between 10-40℃.

[0055] This application uses the SiO2-TiO2-RO (R: Ca, Sr, Ba) system as a basis to obtain glass with low transition temperature, small linear expansion coefficient, good crystallization performance, high transmittance, excellent chemical stability and processing performance.

[0056] This application first provides a lanthanum flint optical glass comprising the following components in molar percentage of cations:

[0057] Si 4+ : 20-40%, preferably 22-35%;

[0058] B 3+ : 0-25%, preferably 5-22%;

[0059] La 3+ 0-5%, preferably 1-4%;

[0060] Zn 2+ : 0-10%, preferably 3-8%;

[0061] Zr 4+ 0-5%, preferably 2-4%

[0062] Ti 4+ : 6-16%, preferably 8-13%;

[0063] Nb 5+ 0-3%, preferably 1-2%;

[0064] Ba 2+ : 0-18%, preferably 3-15%;

[0065] Sr 2+ : 0-10%, preferably 5-8%;

[0066] Na + 5-20%, preferably 10-15%;

[0067] Sb 3+ : 0-0.1%, preferably 0-0.05%;

[0068] The refractive index of the lanthanum flint optical glass is 1.710-1.783; the Abbe number is 32.0-38.2.

[0069] Si 4+ It is a glass network forging, an essential component for ensuring the stability of glass crystallization. It can improve the mechanical properties of glass, such as hardness, abrasion resistance, and chemical stability, and can also increase the viscosity of glass, thus making glass forming easier to control. If Si 4+ If the content is too low, the glass's ability to dissolve alkaline earth metals will decrease sharply, resulting in a significant deterioration in the glass's crystallization properties. This is detrimental to reducing the linear expansion coefficient. Simultaneously, the glass's devitrification resistance and chemical stability will also deteriorate drastically, and its viscosity will decrease, making it difficult to eliminate streaks during the forming process. When excessive Si is introduced... 4+ When this happens, the water resistance of the glass decreases, the liquidus temperature and transition temperature of the glass rise sharply, the batch material becomes difficult to melt, and some Si... 4+ It may not be able to integrate into the glass, easily generating foreign matter during melting, and its crystallization performance will deteriorate accordingly. Simultaneously, the viscosity increases, hindering the elimination of bubbles and streaks, thus reducing the internal quality of the glass. Therefore, based on the molar percentage of cations, the Si of this application... 4+ The content is controlled between 20-40%, preferably 22-35%, and more preferably 25-30%.

[0070] B 3+As a glass network forging agent, it can improve the meltability of glass and lower the glass transition temperature. However, excessive presence can deteriorate the chemical stability, crystallization performance, and formability of the glass, causing surface crystallization, increasing volatilization during the melting process, and reducing the stability and optical uniformity of optical constants. When present in an appropriate amount in glass, it can improve the strength of the glass network; however, excessive presence can damage the network structure, reduce the chemical stability of the glass, hinder the adjustment of optical constants, increase abrasion, reduce hardness, and compromise mechanical properties. Therefore, based on the molar percentage of cations, B of this application... 3+ The content is controlled at 0-25%, preferably 5-22%, and more preferably 12-20%.

[0071] Based on the above effects, this application uses Si as a molar percentage of cations. 4+ With B 3+ The sum ∑ Si 4+ +B 3+ The control ratio is 33-54%, preferably 40-50%; if ∑Si 4+ +B 3+ If the total content is too low, the mechanical properties, devitrification resistance, and chemical stability of the glass will deteriorate; conversely, the viscosity of the glass may be too high, failing to achieve the expected optical performance.

[0072] B 3+ With Si 4+ The ratio of B 3+ / Si 4+ This ratio determines the network structure of the glass and its ability to dissolve alkaline earth metals. The smaller this ratio, the stronger the ability to dissolve alkaline earth metals, which is more beneficial to improving the glass's crystallization performance, chemical properties, and mechanical properties. Therefore, in this invention, B, calculated as a cation molar percentage, 3+ With Si 4+ The ratio of B 3+ / Si 4+ The value is 0-1.2, preferably 0.3-0.9.

[0073] La 3+ It can increase the refractive index of glass, improving its resistance to devitrification and chemical stability. However, due to its large ionic radius, if La... 3+ A content exceeding 5% will increase the liquidus temperature, density, chemical stability, and hardness of the glass. Therefore, based on the molar percentage of cations, the La content in this application... 3+ The content is 0-5%, preferably 2-3%.

[0074] Zr 4+Zr is a network intermediate. When there is sufficient free oxygen in the glass, it can enter the glass network structure, thereby improving the glass's crystallization properties, chemical stability, and mechanical properties. It can also increase the glass viscosity and the transmittance of the glass to visible wavelengths. However, due to its high melting point, if its content is too high, it will lead to an increase in melting temperature and liquidus temperature, a decrease in the glass's devitrification resistance, and the formation of foreign matter, affecting the internal quality of the glass. Therefore, Zr content, expressed as a cation molar percentage, is limited. 4+ The content is controlled at 0-5%, preferably 2-4%.

[0075] Ti 4+ The role of Nb 5+ Similar, but Ti 4+ It is a network intermediate that, when the free oxygen content is appropriate, exists in a titanium-oxygen tetrahedral structure, strengthening the glass network and thus improving the glass's crystallization properties, chemical stability, and mechanical properties. Additionally, Ti... 4+ It does not show color in glass and will not cause coloring of the glass. However, if Ti 4+ Adding excessive amounts of Ti 4+ It exists in the glass structure as a network exosome (low valence state), which not only deteriorates crystallization performance but also intensifies glass coloring, failing to meet the requirements for high-definition glass. Therefore, based on the molar percentage of cations, this application uses Ti... 4+ The content is controlled at 6-16%, preferably 8-13%.

[0076] Based on the above effects, Si, in terms of cation molar percentage 4+ B 3+ With Ti 4+ The sum ∑ Si 4+ +B 3+ +Ti 4+ It can be controlled to be 40-65%, preferably 45-60%, and more preferably 50-58%. If ∑Si 4+ +B 3+ +Ti 4+ If the content of ∑Si is too low, it will be detrimental to the improvement of the crystallization performance and chemical stability of the glass. 4+ +B 3+ +Ti 4+ If the content is too high, the crystallization performance and mechanical properties will deteriorate, and high-performance glass cannot be obtained.

[0077] Nb 5+ It is an effective component for improving glass dispersion; when added in appropriate amounts, it can improve devitrification resistance and chemical stability, and suppress the decrease in transmittance in the short-wavelength region. However, if Nb... 5+Excessive Nb content significantly increases glass costs and drastically raises the liquidus temperature, hindering the production of low-density, low-cost glass. Therefore, based on the molar percentage of cations, Nb... 5+ The content is controlled at 0-3%, preferably 1-2%.

[0078] Based on the above effects, Nb, in molar percentage of cations 5+ With Ti 4+ The ratio of Nb 5+ / Ti 4+ The value should be controlled between 0-0.5, preferably 0.1-0.3. If Nb 5+ / Ti 4+ If the glass is too large, the cost and density of the glass will increase significantly, failing to achieve the expected cost-effectiveness and meet the market's demand for lightweighting, and the crystallization performance will also deteriorate.

[0079] Ba 2+ 、Sr 2+ Both have the effect of adjusting optical constants, while providing sufficient free oxygen to promote the formation of tetrahedral structures of B2O3 and TiO2, thus enhancing the glass network. 2+ 、Sr 2+ In addition to ensuring optical performance, the appropriate amount of [a substance] can also improve the glass's resistance to devitrification, light transmittance, chemical stability, and mechanical properties.

[0080] But if Ba 2+ and / or Sr 2+ Excessive content of certain compounds leads to an increase in non-bridging oxygens, and some Ba... 2+ and / or Sr 2+ Disruption of the network structure in the form of an external network leads to decreased resistance to devitrification and chemical stability, reduced hardness, and increased abrasion resistance. Therefore, based on the molar percentage of cations, Ba... 2+ The content of Sr is controlled at 0-18%, preferably 3-15%, more preferably 6-13%; 2+ The content is controlled at 0-10%, preferably 5-8%.

[0081] Due to the mixed alkaline earth metal effect, Sr 2+ with Ba 2+ When present together, they significantly improve the crystallization properties, mechanical properties, and chemical stability of glass. Therefore, based on the above effects, Ba, in terms of cation molar percentage, 2+ With Sr 2+ The sum ∑Ba 2+ +Sr 2+The total content is controlled at 8-28%, preferably 10-22%, and more preferably 12-18%. Meanwhile, although Ba and Sr are adjacent elements in the same group, their roles in glass are not entirely the same, and their solubilities differ significantly. In this application, the solubility of Ba is significantly greater than that of Sr, and Ba is more conducive to improving the crystallization properties and chemical stability of the glass; therefore, Ba... 2+ The content can be higher than that of Sr. 2+ The content of.

[0082] Zn 2+ It is also a network intermediate. When present in appropriate amounts, it can not only promote a denser glass structure, reduce the linear expansion coefficient of glass, improve the thermal and chemical stability of glass, and increase the refractive index of glass, but also improve melting and crystallization properties, and lower the transition temperature and liquidus temperature. However, Zn... 2+ When the concentration is too high, the abrasion resistance will increase significantly, the hardness will decrease significantly, and the chemical stability will also deteriorate, which is detrimental to improving the mechanical properties of the glass and to maintaining the crystallization resistance and high transmittance of the glass in this application. Therefore, based on the molar percentage of cations, Zn 2+ The content is controlled at 0-10%, preferably 3-8%.

[0083] Based on the above effects, Ba, in terms of cation molar percentage, 2+ 、Sr 2+ With Zn 2+ The sum ∑Ba 2+ +Sr 2+ +Zn 2+ The control range is 15-36%, preferably 17-30%. If ∑Ba 2+ +Sr 2+ +Zn 2+ If the free oxygen level is too low, there will be insufficient free oxygen, and intermediates such as B and Ti in the glass will not be able to capture enough oxygen to transform into a tetrahedral structure, which is detrimental to improving the crystallization performance, mechanical properties, and chemical stability of the glass; if ∑Ba 2+ +Sr 2+ +Zn 2+ If the temperature is too high, the amount of non-bridging oxygen increases, the glass structure becomes looser, and the crystallization performance deteriorates.

[0084] Furthermore, in terms of cation molar percentage, Si 4+ B 3+ Ti 4+ Zn 2+ With Zr 4+ The sum ∑ Si 4+ +B 3+ +Ti 4+ +Zn 2 + +Zr 4+The content is 53-74%, preferably 58-70%, and further preferably 60-68%. (With ∑Si) 4+ +B 3+ +Ti 4+ Similarly, if ∑Si 4+ +B 3 + +Ti 4+ +Zn 2+ +Zr 4+ If the content of ∑Si is too low, it will be detrimental to the improvement of the crystallization performance and chemical stability of the glass. 4+ +B 3+ +Ti 4+ +Zn 2+ +Zr 4+ If the content is too high, the crystallization performance and mechanical properties will deteriorate, and high-performance glass cannot be obtained.

[0085] Alkali metal ions Na + The introduction of Na can promote the melting of various components, lower the glass transition temperature and liquidus temperature, and provide free oxygen to promote the formation of tetrahedral structures. However, if added in excess, it will disrupt the network structure, reduce the chemical stability and mechanical properties of the glass, and increase the coefficient of linear expansion. Therefore, this application uses Na... + The content is controlled at 5-20%, preferably 10-15%.

[0086] Based on the above effects, the present invention, in terms of cation molar percentage, contains Ba 2+ 、Sr 2+ with Na + The sum ∑Ba 2+ +Sr 2+ +Na + The control value is 20-44%, preferably 22-40%, and more preferably 25-35%. If ∑Ba 2+ +Sr 2+ +Na + If the content of ∑Ba is too low, there will be insufficient free oxygen, and intermediates such as B and Ti in the glass will not be able to capture enough oxygen to transform into a tetrahedral structure, which is not conducive to improving the crystallization performance, mechanical properties and chemical stability of the glass; if ∑Ba 2+ +Sr 2+ +Na + Excessive content of certain substances leads to an increase in non-bridging oxygen, resulting in a looser glass structure and poorer crystallization performance.

[0087] Based on the above effects, Zn 2+ Ba 2+ With Sr 2+ The sum of and B 3+ With Ti 4+ The ratio of the sums (Zn) 2++Ba 2+ +Sr 2+ ) / (Ti 4+ +B 3+ The Zn content is controlled to be 0-2.5, preferably 0.3-2, and further preferably 0.5-1.0; 2+ Ba 2+ With Sr 2+ The sum of Ti 4+ B 3+ With Zr 4+ The ratio of the sums (Zn) 2+ +Ba 2+ +Sr 2+ ) / (Ti 4+ +B 3+ +Zr 4+ The value of Ba should be controlled between 0 and 2.1, preferably 0.3 to 1.7, and even more preferably 0.5 to 1.2; 2+ 、Sr 2+ with Na + The sum of Ti 4+ B 3+ Zn 2+ With Zr 4+ The ratio of the sums (Ba) 2+ +Sr 2+ +Na + ) / (Ti 4+ +B 3+ +Zn 2+ +Zr 4+ The ratio should be controlled between 0 and 2, preferably between 0.3 and 1.5, and even more preferably between 0.5 and 1.0. If the above ratio is too large, the amount of the network body increases, the glass structure expands, which is not conducive to obtaining glass with excellent mechanical properties and devitrification resistance.

[0088] Sb 3+ It can be added as a defoamer, but its content should be below 0.1%, and if Sb₂O₃ exceeds 0.1%, the colorfastness and internal transmittance of the glass will deteriorate. Additionally, Sb... 3+ Excessive Sb content can intensify the coloring of the glass. Furthermore, when manufacturing glass preforms using pressure molding, the surface of the formed body is prone to unevenness and blurring, failing to meet the increasing requirements for optical design in recent years. Therefore, Sb 3+ The component content is limited to less than 0.1%, preferably less than 0.05%, and more preferably not added.

[0089] alkali metal ions Li + K + Although the introduction of sodium can lower the sag temperature and liquidus temperature of glass, its crystallization performance and chemical properties are not as good as those after adding sodium. + And Li +The price is relatively expensive and the increase is significant; therefore, this application prefers not to add it.

[0090] Raw materials such as Gd, Ta, and Ge are extremely expensive and do not meet the requirements of modern lightweighting and low cost. Therefore, this application prefers not to add them.

[0091] Yb absorbs in the near-infrared band, which is not conducive to improving the transmittance of glass. Y will destroy the network structure of glass, so this application prefers not to add it.

[0092] Th, Pb, As, Cd, Hg, Sn, Fe, Co, Ce, Te, V, Mo, Cr, Mn, Ni, Cu, Ag, etc. are harmful to the environment or easily color glass, and therefore, this application does not preferably add them.

[0093] P and F are volatile or hygroscopic components that can produce volatile streaks, increasing the difficulty of production. Preferably, they are not added in this application.

[0094] Bi and Pb are highly toxic substances that not only strongly corrode the platinum materials used in the melting process, but also corrode the molding dies. Therefore, they are not added in this application.

[0095] To ensure the transmittance of the lanthanum flint optical glass described in this application, preferably, the optical glass provided in this application does not contain elements such as Tl, Os, Be, Se, Te, Cr, and Co.

[0096] Furthermore, the lanthanum flint optical glass of the present invention has at least one of the following properties:

[0097] The linear expansion coefficient α of the lanthanum flint optical glass -50 / 80℃ Not exceeding 82×10 -7 / ℃;

[0098] The lanthanum flint optical glass has a transition temperature Tg not exceeding 580℃, a sag temperature Ts not exceeding 630℃, and a liquidus temperature L... T Not exceeding 1000℃;

[0099] The tinting λ of the lanthanum flint optical glass 80 λ in / λ5 80 Below 415nm, λ5 is below 355nm.

[0100] The hardness of the lanthanum flint optical glass is not less than 550×10. 7 Pa;

[0101] The abrasion resistance of the lanthanum flint optical glass is 80-150.

[0102] The density of the lanthanum flint optical glass does not exceed 3.85 g / cm³. 3 .

[0103] The lanthanum flint optical glass has a moisture resistance, water resistance, alkali resistance, and washing resistance of all being grade 1.

[0104] The lanthanum flint optical glass has an acid resistance stability of level 2 or above.

[0105] This application also provides a method for preparing lanthanum flint optical glass according to this application, comprising: 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.

[0106] Specifically, each component is weighed and mixed evenly according to a specified ratio to form a batch material. The batch material is then put into a smelting apparatus made of quartz, corundum, or precious metals (Au, Pt, etc.), melted, stirred, and clarified at a temperature of 1250-1400℃, and then poured or poured into a molding die to form a shape, or directly pressed into a shape. Finally, after annealing and cooling, the optical glass or optical element of this application is obtained.

[0107] The present invention also provides an optical element comprising lanthanum flint optical glass according to the present application.

[0108] Example

[0109] 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.

[0110] The components of Examples 1-35 in Tables 1-7 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 1300°C. After stirring and clarifying at 1360°C for 15 hours, the temperature is lowered to 1250°C and held for 1 hour 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.

[0111] Comparative Example

[0112] The raw materials corresponding to each component of Comparative Example AC in Table 8 were weighed according to the specified proportions and prepared using the same preparation method as in Examples 1-35 to obtain the optical glass of Comparative Example AB.

[0113] Performance testing

[0114] 1. Refractive index n d Abbe number υ d

[0115] The refractive index n of the obtained optical glass was determined according to the test method of GB / T7962.1-2010. d Abbe number υ d The determination of n listed in the table d υ d The data is for annealing at -30℃.

[0116] 2. Glass abrasion degree F A

[0117] Wear degree is measured according to the test method specified in GB / T 7962.19.

[0118] 3. Knoop hardness (HK) of glass

[0119] Knoop hardness was measured according to the test method specified in ISO 9385.

[0120] 4. The linear expansion coefficient α of glass 20 / 300℃

[0121] The measurement shall be performed according to the method specified in GB / T 7962.16.

[0122] 5. Glass transition temperature Tg and sag temperature Ts

[0123] The measurement shall be performed according to the method specified in GB / T 7962.16.

[0124] 6. Density ρ

[0125] The density of the obtained optical glass was determined according to the test method of GB / T7962.20-2010.

[0126] 7. Shading degree λ 80 / λ5

[0127] The short-wavelength transmission spectral characteristics of optical glass are expressed using colorimetric λ. 80 / λ5 represents λ. 80 λ5 refers to the wavelength corresponding to a glass transmittance of 80%, while λ5 refers to the wavelength corresponding to a glass transmittance of 5%.

[0128] 8. Water resistance stability D W Acid resistance stability D A (Powder method)

[0129] 1) Water resistance stability D W

[0130] 10 g ± 0.0001 g of powdered glass (passed through a 40-32 mesh sieve) with a particle size of 450-560 μm was placed in a filter. The glass was then immersed in a quartz glass flask containing 80 mL of distilled water (pH 6.5-7.5) and kept at a constant temperature of 98-100 °C for 60 minutes. All glass particles were then transferred to a pre-weighed filter, washed with 80 mL of anhydrous ethanol, and dried at 120 ± 5 °C to constant weight. The percentage of glass leaching was calculated using the following formula:

[0131]

[0132] In the formula: D W —Percentage of glass leaching, %;

[0133] B—mass of the filter and sample, in g;

[0134] C—Mass of the filter and the etched sample, in g;

[0135] A—Filter mass, g.

[0136] Based on the percentage of water leaching by mass, the water resistance stability D of optical glass is determined. W They are divided into six categories, as shown in Table A below:

[0137] Table A

[0138]

[0139] 2) Acid resistance stability D A

[0140] With D W The determination method is the same; a 0.01 mol / L nitric acid aqueous solution is added to the flask for treatment, and the glass leaching percentage is calculated according to the following formula:

[0141]

[0142] In the formula: D A —Percentage of glass leaching, %;

[0143] B—mass of the filter and sample, in g;

[0144] C—mass of the filter and the etched sample, in g;

[0145] A—Filter mass, g.

[0146] Based on the percentage of leaching by mass, the acid resistance stability D of optical glass is determined. A They are divided into six categories, as shown in Table B below:

[0147] Table B

[0148]

[0149] 9. Moisture resistance stability R C Acid resistance R A (Surface method)

[0150] 1) Moisture resistance stability R C

[0151] Under conditions of 50℃ and 85% relative humidity, the stability of optical glass against humid atmospheres is classified into three levels based on the time required for hydrolysis spots to form on the polished glass surface, as shown in Table C below:

[0152] Table C

[0153] level 1 2 3 Time (H) >20 5～20 <5

[0154] 2) Acid resistance R A

[0155] Under the action of acetic acid solution at 0.1N (pH=2.9) and 50℃, the acid resistance stability of optical glass is divided into three levels according to the time required for interference colors to appear on the polished glass surface, or for surface discoloration or peeling to occur, as shown in Table D below:

[0156] Table D

[0157] level 1 2 3 Time (H) >5 1～5 <1

[0158] 10. Washing resistance stability RP(S), alkali resistance stability R OH (S)(Surface Method)

[0159] 1) Alkali resistance stability R OH (S)

[0160] A 40mm × 40mm × 5mm sample, polished on all six sides, was immersed in a 0.01mol / L sodium hydroxide aqueous solution at a constant temperature of 50℃ ± 3℃ for 15 hours with thorough stirring. The leaching mass per unit area was calculated as mg / (cm²). 2 •15h), to improve the alkali resistance stability R of optical glass OH (S) is divided into five levels, as shown in Table E below:

[0161] Table E

[0162]

[0163] 2) Washability stability RP(S)

[0164] A 35mm × 35mm × 8mm sample, polished on all six sides, was immersed in Na₅P₃O₂ at a constant temperature of 50℃ ± 3℃ and a concentration of 0.01mol / L, with thorough stirring.10 In aqueous solution for 1 hour. Based on the average leaching mass per unit area, the unit is mg / (cm²). 2 The wash resistance stability RP(S) of optical glass is divided into five levels, as shown in Table F below:

[0165] Table F

[0166]

[0167] 11. Liquidus temperature L T

[0168] After remelting the glass, it was sequentially cooled to different temperatures and held at those temperatures for 45 minutes before being poured into crystallized samples. The highest temperature at which crystallization occurred in the sample was the liquidus temperature L. T .

[0169] The refractive index n of the optical glass prepared in Examples 1-35 d Abbe number υ d Wear degree F A Hardness HK, linear expansion coefficient α -50 / 80℃ Transition temperature T g , sag temperature Ts, density ρ, chromaticity λ 80 / λ5、Water resistance stability D W Moisture resistance stability R C Acid resistance R A Acid resistance stability D A Alkali resistance stability R OH (S), Washability RP(S), Liquidus Temperature L T The data are listed in Tables 1-7; the data obtained by measuring the comparative example AC are listed in Table 8.

[0170] Table 1: Glass composition and performance parameters of Examples 1-5

[0171]

[0172] Table 2: Glass composition and performance parameters of Examples 6-10

[0173]

[0174] Table 3: Glass composition and performance parameters of Examples 11-15

[0175]

[0176] Table 4: Glass composition and performance parameters of Examples 16-20

[0177]

[0178] Table 5: Glass composition and performance parameters of Examples 21-25

[0179]

[0180] Table 6: Glass composition and performance parameters of Examples 26-30

[0181]

[0182] Table 7: Glass composition and performance parameters of Examples 31-35

[0183]

[0184] Table 8: Glass composition and performance parameters of Comparative Example AC

[0185]

[0186] As can be seen from Tables 1-7, the refractive index n of the optical glass in Examples 1-35 of this application is... d Within the range of 1.71-1.783, the Abbe number υ d Within the range of 32-38.1, its chromaticity, λ 80 The wavelength is no more than 415 nm, the λ5 is no more than 355 nm, and the density is 3.85 g / cm³. 3 The following values ​​have a wear resistance of 83-150 and a hardness of (550-596)×10⁻⁶. 7 Pa, linear expansion coefficient α -50 / 80℃ All are (74-82)×10 -7 / ℃, transition temperature Tg is 526-578℃, relaxation temperature Ts is 580-630℃, liquidus temperature L T For temperatures below 1100℃, the surface treatment achieves Grade 1 stability in terms of moisture resistance, alkali resistance, acid resistance, and washability, while the powder treatment achieves Grade 1-2 acid resistance. It exhibits excellent optical, mechanical, chemical stability, and processability, making it suitable for mass production and applicable to optical imaging systems such as cameras and projectors.

[0187] As can be seen from Table 8, Comparative Example A contains more than 10% Nb. 5+ The cost is relatively high, which does not meet the market's demand for high cost-performance; Comparative Example B contains more than 20% Ti. 4+ The color gradation is poor, which does not meet the high-definition requirements of high-end optical systems, and the liquidus temperature is also high, making production difficult; the comparative example C contains 30% Zn. 2+ The liquidus temperature also exceeds 1100℃, which not only makes it easy to corrode the crucible during the melting process, but also makes the glass chemically unstable and unsuitable for processing and harsh environmental conditions.

[0188] Industrial availability

[0189] The lanthanum flint optical glass and its preparation method described in this application can be industrially produced. It can be processed into various optical components such as lenses and preforms through cold working, hot working, and precision molding, and applied to fields such as cameras, optical communication, and smart homes. It meets the market demand for high cost-effectiveness and lightweight applications, has low tinting strength, and can also improve the imaging clarity of optical systems to meet their high-definition requirements.

[0190] 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.

[0191] 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. A lanthanum flint optical glass, characterized in that, It contains the following components in molar percentage of cations: And 4+ :20-40%; B 3+ ：0-25％； The 3+ 0.3-5%; Zn 2+ :0-10%; Zr 4+ ：0-5％； Of 4+ :7.8-16%; Nb 5+ :0-3%; Not 2+ :0-18%; Sr 2+ ：0-10％； That + :10.6-20%; Sb 3+ :0-0.1%; Ba, in molar percentage of cations 2+ With Sr 2+ The sum ∑Ba 2+ +Sr 2+ It ranges from 8% to 28%. Ba 2+ 、Sr 2+ With Zn 2+ The sum ∑Ba 2+ +Sr 2+ +Zn 2+ It ranges from 15% to 36%. Ba 2+ 、Sr 2+ with Na + The sum ∑Ba 2+ +Sr 2+ +Na + It ranges from 20% to 44%. The refractive index of the lanthanum flint optical glass is 1.710-1.783; the Abbe number is 32.0-38.

2.

2. The lanthanum flint optical glass according to claim 1, characterized in that, It contains the following components in molar percentage of cations: And 4+ :22-35%; B 3+ ：5-22％； The 3+ 1-4%; Zn 2+ :3-8%; Zr 4+ ：2-4％； Of 4+ :8-13%; Nb 5+ :1-2%; Not 2+ :3-15%; Sr 2+ ：5-8％； That + :10.6-15%; Sb 3+ :0-0.05%。 3. The lanthanum flint optical glass according to claim 1 or 2, characterized in that, Si, in molar percentage of cations 4 + With B 3+ The sum ∑ Si 4+ +B 3+ It ranges from 33% to 54%. B 3+ With Si 4+ The ratio of B 3+ / Si 4+ The range is 0-1.2; Si 4+ B 3+ With Ti 4+ The sum ∑ Si 4+ +B 3+ +Ti 4+ It is 40-65%; Si 4+ B 3+ Ti 4+ Zn 2+ With Zr 4+ The sum ∑ Si 4+ +B 3+ +Ti 4+ +Zn 2+ +Zr 4+ The range is 53-74%.

4. The lanthanum flint optical glass according to claim 3, characterized in that, Si, in molar percentage of cations 4+ With B 3+ The sum ∑ Si 4+ +B 3+ It is 40-50%; B 3+ With Si 4+ The ratio of B 3+ / Si 4+ It is 0.3-0.9; Si 4+ B 3+ With Ti 4+ The sum ∑ Si 4+ +B 3+ +Ti 4+ It is 45-60%; Si 4+ B 3+ Ti 4+ Zn 2+ With Zr 4+ The sum ∑ Si 4+ +B 3+ +Ti 4+ +Zn 2+ +Zr 4+ It is 58-70%.

5. The lanthanum flint optical glass according to claim 1 or 2, characterized in that, Ba, in molar percentage of cations 2 + With Sr 2+ The sum ∑Ba 2+ +Sr 2+ It is 10-22%; Ba 2+ 、Sr 2+ With Zn 2+ The sum ∑Ba 2+ +Sr 2+ +Zn 2+ It is 17-30%; Ba 2+ 、Sr 2+ with Na + The sum ∑Ba 2+ +Sr 2+ +Na + It ranges from 22% to 40%.

6. The lanthanum flint optical glass according to claim 1 or 2, characterized in that, Zn, in molar percentage of cations 2 + Ba 2+ With Sr 2+ The sum of and B 3+ With Ti 4+ The ratio of the sums (Zn) 2+ +Ba 2+ +Sr 2+ ) / (Ti 4+ +B 3+ The value is 0-2.5; Zn 2+ Ba 2+ With Sr 2+ The sum of Ti 4+ B 3+ With Zr 4+ The ratio of the sums (Zn) 2+ +Ba 2+ +Sr 2+ ) / (Ti 4+ +B 3+ +Zr 4+ The range is 0-2.1; Ba 2+ 、Sr 2+ with Na + The sum of Ti 4+ B 3+ Zn 2+ With Zr 4+ The ratio of the sums (Ba) 2+ +Sr 2+ +Na + ) / (Ti 4+ +B 3+ +Zn 2+ +Zr 4 + The ratio of ) is 0-2.

7. The lanthanum flint optical glass according to claim 6, characterized in that, Zn, in molar percentage of cations 2+ Ba 2+ With Sr 2+ The sum of and B 3+ With Ti 4+ The ratio of the sums (Zn) 2+ +Ba 2+ +Sr 2+ ) / (Ti 4+ +B 3+ The value is 0.3-2; Zn 2+ Ba 2+ With Sr 2+ The sum of Ti 4+ B 3+ With Zr 4+ The ratio of the sums (Zn) 2+ +Ba 2+ +Sr 2+ ) / (Ti 4+ +B 3+ +Zr 4+ The value is 0.3-1.7; Ba 2+ 、Sr 2+ with Na + The sum of Ti 4+ B 3+ Zn 2+ With Zr 4+ The ratio of the sums (Ba) 2+ +Sr 2+ +Na + ) / (Ti 4+ +B 3+ +Zn 2+ +Zr 4 + The ratio is 0.3-1.

5.

8. The lanthanum flint optical glass according to claim 1 or 2, characterized in that, Nb, in molar percentage of cations 5 + With Ti 4+ The ratio of Nb 5+ / Ti 4+ It is 0-0.

5.

9. The lanthanum flint optical glass according to claim 8, characterized in that, Nb, in molar percentage of cations 5+ With Ti 4+ The ratio of Nb 5+ / Ti 4+ It is 0.1-0.

3.

10. The lanthanum flint optical glass according to claim 1 or 2, characterized in that, The linear expansion coefficient α of the lanthanum flint optical glass -50 / 80℃ Not exceeding 82×10 -7 / ℃; The lanthanum flint optical glass has a transition temperature Tg not exceeding 580℃, a sag temperature Ts not exceeding 630℃, and a liquidus temperature L... T Not exceeding 1000℃; The tinting λ of the lanthanum flint optical glass 80 λ in / λ5 80 Below 415nm, λ5 is below 355nm.

11. The lanthanum flint optical glass according to claim 1 or 2, characterized in that, The hardness of the lanthanum flint optical glass is not less than 550×10. 7 Pa; The abrasion resistance of the lanthanum flint optical glass is 80-150. The density of the lanthanum flint optical glass does not exceed 3.85 g / cm³. 3 .

12. The lanthanum flint optical glass according to claim 1 or 2, characterized in that, The lanthanum flint optical glass has a moisture resistance, water resistance, alkali resistance, and washing resistance of all being grade 1. The lanthanum flint optical glass has an acid resistance stability of level 2 or above.

13. A method for preparing lanthanum flint optical glass according to any one of claims 1-12, characterized in that, This includes weighing and mixing the components according to the proportions, melting them, and then pouring or casting them into a molding die, or directly pressing them into shape.

14. An optical element, characterized in that, Including the lanthanum flint optical glass according to any one of claims 1-12.

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