Optical glass, preparation method thereof and vehicle-mounted lens

Abstract

The invention provides optical glass, a preparation method thereof and a vehicle-mounted lens. The optical glass comprises the following components in molar percentage: 5.0-13.0% of Si < 4 + >, 5.0-13.0% of Si < 4 + >, and the balance of glass. B < 3 + >: 24.5-45.0%; la < 3 + >: 12.0%-19.99%; 6.0 to 13.0% of Nb < 5 + >; 8.0 to 13.0% of Ti < 4 + >; 2.0 to 6.0 percent of Zr < 4 + >; 10.01%-21.0% of Zn < 2 + >; 0 to 0.2 percent of Sb < 3 + >; the refractive index nd of the optical glass is 1.89 or above, and the Abbe number upsilon d of the optical glass is 28 or above. The optical glass provided by the invention has the advantages of low thermal expansion coefficient, good thermal conductivity, high hardness, high strength and good chemical stability, can be used in various environments, and is especially suitable for vehicle-mounted lenses for intelligent driving.

Description

Technical Field

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

[0002] In recent years, with the rapid development of intelligent driving vehicle technology and industry, automotive lenses, as one of the visual recognition systems, have experienced vigorous development. Compared with commonly used imaging applications such as smartphones and SLR cameras, the quality of automotive lenses is closely related to life safety. Therefore, automotive lenses place greater emphasis on equipment safety and reliability, especially those lenses exposed on the exterior of the vehicle, such as reversing cameras, front-view cameras, and rearview mirror auxiliary cameras. Due to the harsh outdoor natural environment, higher requirements are placed on the performance of the optical glass used in the lenses to ensure the long-term safety of the vehicle during driving, especially in terms of resistance to cracking under large outdoor temperature changes, scratch resistance, and resistance to rain and fog.

[0003] Refractive index n d An Abbe number of υ is above 1.89. d High-refractive-index optical glass with a refractive index of 28 or higher is currently mainly used in products such as digital mobile phones, digital cameras, and projectors. Typical high-refractive-index optical glass has a large coefficient of thermal expansion, resulting in poor crack resistance and a tendency to shatter under rapid temperature changes. It also tends to have low hardness and strength, making it susceptible to damage from pebbles. The high-refractive-index optical glass of this invention possesses excellent thermal, mechanical, and chemical stability properties, along with superior characteristics such as low specific gravity, high transmittance, and a wide field of view, effectively meeting the stringent requirements of automotive lenses. Summary of the Invention

[0004] The problem the invention aims to solve

[0005] In view of the technical problems existing in the prior art, the object of the present invention is primarily to provide an optical glass with excellent thermal and mechanical properties, which exhibits strong crack resistance under temperature differences. The refractive index n of the optical glass is... d An Abbe number of υ is above 1.89. d With a pH value above 28, it exhibits excellent chemical stability, making it suitable for use in various environments, especially for automotive lenses used in intelligent driving systems. It also features low specific gravity, a light glass hue, good crack resistance, excellent devitrification resistance, and superior internal product quality.

[0006] The present invention also provides a method for preparing optical glass, which is simple and easy to implement, uses readily available raw materials, has excellent process performance, low production cost, is suitable for production, and has good mass production capability.

[0007] Solution for solving the problem

[0008] This invention provides an optical glass, wherein the optical glass contains the following components by mole percentage:

[0009] Si 4+ : 5.0~13.0%, preferably 5.5~12.5%;

[0010] B 3+ : 24.5~45.0%, preferably 25.0~44.5%;

[0011] La 3+ : 12.0~19.99%, preferably 12.5~19.8%;

[0012] Nb 5+ : 6.0~13.0%, preferably 6.5~12.5%;

[0013] Ti 4+ : 8.0~13.0%, preferably 8.5~12.5%;

[0014] Zr 4+ : 2.0~6.0%, preferably 2.5~5.5%;

[0015] Zn 2+ : 10.01~21.0%, preferably 10.5~20.5%;

[0016] Sb 3+ : 0~0.2%, preferably 0.01~0.15%;

[0017] The refractive index n of the optical glass d An Abbe number of υ is above 1.89. d It is 28 or above.

[0018] The optical glass according to the present invention, wherein, in molar percentage, Ti 4+ With Ti 4+ and Nb 5+ The ratio of the sum of the contents of Ti 4+ / (Ti 4+ +Nb 5+ The value is less than 0.6, preferably less than 0.59;

[0019] Zn 2+ Ti 4+ 、Nb 5+ The sum of the contents of La 3+ The ratio of Zn content 2+ +Ti 4+ +Nb 5+ ) / La 3+ The value should be no less than 1.62, preferably no less than 1.64.

[0020] The optical glass according to the invention, wherein, in molar percentage, Nb 5+ with La 3+ The ratio of Nb content 5+ / La 3+ It should be no less than 0.415, preferably no less than 0.42;

[0021] La 3+ The content of Ti 4+ and Nb 5+ The ratio of the sum of the contents of La 3+ / (Ti 4+ +Nb 5+ The value should not exceed 1.56, preferably not exceed 1.50.

[0022] The optical glass according to the present invention, wherein, in molar percentage, Ti 4+ With B 3+ The ratio of Ti content 4+ / B 3+ The value should not exceed 0.8, and preferably should not exceed 0.75.

[0023] In mole percentage, B 3+ With Si 4+ The ratio of the content of B 3+ / Si 4+ It should be greater than 1.0, preferably greater than 1.1;

[0024] In mole percentage, B 3+ With Si 4+ The sum of the contents of B 3+ +Si 4+ The content is 30.0% to 60.0%, preferably 31.0% to 59.0%.

[0025] According to the optical glass of the present invention, the optical glass does not contain Gd. 3+ Y 3+ Yb 3+ Sn 4+ Al 3+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Li + Na + K + 、Rb + Cs + One or more combinations of the above.

[0026] According to the optical glass of the present invention, the coefficient of thermal expansion α of the optical glass is... -30~70Not greater than 60×10 -7 / K;

[0027] The thermal conductivity λ of the optical glass is not less than 1.0 W / (m·K).

[0028] According to the optical glass of the present invention, the density of the optical glass is not greater than 4.60 g / cm³. 3 ;

[0029] The Knoop hardness H of the optical glass K 700×10 7 Pa or above;

[0030] The bending strength σ of the optical glass b It is above 110 MPa.

[0031] According to the optical glass of the present invention, wherein the tinting strength λ of the optical glass is... 70 λ in / λ5 70 Below 425nm, λ5 is below 365nm;

[0032] The transition temperature Tg of the optical glass is below 635℃;

[0033] Liquidus temperature L T Below 1050℃.

[0034] The present invention also provides a method for preparing optical glass according to the present invention, 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.

[0035] The present invention also provides a vehicle-mounted lens, which includes the optical glass described in the present invention.

[0036] The effects of the invention

[0037] The optical glass of this invention has the advantages of low coefficient of thermal expansion, good thermal conductivity, high hardness, high strength, good crack resistance, and excellent chemical stability. It can be used in various environments, and is especially suitable for automotive lenses for intelligent driving.

[0038] The optical glass of this invention also has the advantages of high refractive index, low specific gravity and light glass color, which can realize the requirements of lightweight and miniaturized optical systems, wide field of view and clear imaging. It is a glass material with excellent performance and has a wide range of applications in optical design.

[0039] The optical glass of this invention has the advantages of good devitrification resistance, excellent processability, low production cost, good mass production capability, and excellent internal quality.

[0040] The optical glass preparation method of the present invention is simple and easy to implement, the raw materials are easy to obtain, the preparation steps are simple, and it is suitable for mass production. Detailed Implementation

[0041] 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.

[0042] 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.

[0043] 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.

[0044] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0045] 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.

[0046] 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.

[0047] In this specification, unless otherwise specified, the content of each component is expressed as a percentage of the total molar amount of the entire composition. In the glass produced by this invention, each component in the above-mentioned amounts is selected for the reasons described below.

[0048] This invention provides an optical glass, which contains the following components by mole percentage:

[0049] Si 4+ : 5.0~13.0%, preferably 5.5~12.5%;

[0050] B3+ : 24.5~45.0%, preferably 25.0~44.5%;

[0051] La 3+ : 12.0~19.99%, preferably 12.5~19.8%;

[0052] Nb 5+ : 6.0~13.0%, preferably 6.5~12.5%;

[0053] Ti 4+ : 8.0~13.0%, preferably 8.5~12.5%;

[0054] Zr 4+ : 2.0~6.0%, preferably 2.5~5.5%;

[0055] Zn 2+ : 10.01~21.0%, preferably 10.5~20.5%;

[0056] Sb 3+ : 0~0.2%, preferably 0.01~0.15%;

[0057] The refractive index n of the optical glass d An Abbe number of υ is above 1.89. d The value is 28 or higher; preferably, the refractive index n d The Abbe number is υ, ranging from 1.89 to 1.95. d The range is 28 to 38.

[0058] Preferably, the sum of the molar percentages of the above-mentioned components of the present invention is 100%.

[0059] Si 4+ It is a glass network structure forging body that can improve the strength and hardness of glass, reduce the coefficient of thermal expansion, thereby improving the crack resistance of glass under temperature differences, and also improve the chemical stability of glass, improve the devitrification resistance of glass, increase the forming viscosity of glass, thereby improving the process capability of high refractive index glass production and increasing the production yield. In molar percentage, if Si... 4+ When the Si content exceeds 13.0%, it becomes difficult to obtain the required optical constants, the glass meltability deteriorates, and the glass transition temperature (Tg) increases significantly. If Si... 4+ When the Si content is below 5.0%, the strength and hardness of the glass decrease, the coefficient of thermal expansion increases, the chemical stability deteriorates, and the deterioration of devitrification resistance worsens; therefore, Si 4+ The content is controlled at 5.0~13.0%, preferably 5.5~12.5%.

[0060] B 3+It is a glass network structure forger that can improve the meltability of glass and lower the transition temperature Tg and glass sag temperature Ts. When an appropriate amount of boron is present in the glass, it enters the glass network structure as boron-oxygen tetrahedra [BO4], which can make the glass structure compact and stable, improve the chemical stability and devitrification resistance of the glass, increase the hardness, strength and other mechanical properties of the glass, reduce the coefficient of expansion, and improve the crack resistance of the glass under thermal temperature differences; on a molar percentage basis, if B 3+ When the content exceeds 45.0%, it will actually damage the network structure, which is detrimental to the stable formation of glass and reduces its chemical stability, thus lowering the refractive index. If B... 3+ When the content of B is below 24.5%, the strength and hardness of the glass decrease, and its resistance to cracking under temperature differences deteriorates; therefore, B 3+ The content is controlled at 24.5-45.0%, preferably 25.0-44.5%.

[0061] In this invention, B is expressed as a molar percentage. 3+ With Si 4+ The sum of the contents of B 3+ +Si 4+ When the temperature is too high, the glass's resistance to devitrification improves, but the refractive index decreases; therefore, B... 3+ +Si 4+ The content is controlled at 30.0~60.0%, preferably 31.0~59.0%.

[0062] In this invention, B is expressed as a molar percentage. 3+ With Si 4+ The ratio of the content of B 3+ / Si 4+ When the temperature is too high, the glass's devitrification resistance decreases, and its chemical stability deteriorates, especially its acid resistance. B 3+ / Si 4+ If the temperature is too low, the meltability of the glass deteriorates, and the transition point increases. In this invention, B is controlled... 3+ / Si 4+ It is greater than 1.0, preferably greater than 1.1, for example: 1~10.

[0063] In this invention, through a suitable B 3+ +Si 4+ With B 3+ / Si 4+ This approach can further balance the glass's melting properties, devitrification resistance, formability, chemical stability, mechanical properties, and thermal properties, achieving the desired effect.

[0064] La 3+It is an effective component for improving the refractive index and Abbe number of glass, playing a crucial role in increasing glass hardness, enhancing chemical stability, and especially weather resistance, while also improving devitrification resistance. Furthermore, compared to other rare earth raw materials with similar functions, La-containing... 3+ The raw material price is relatively cheap, which can reduce the material cost of high-refractive-index glass. If La 3+ If the content is below 12.0%, the glass will struggle to achieve the required Abbe number, and its chemical stability, especially its weather resistance, will deteriorate, as will its devitrification resistance. However, La... 3+ When the content of La exceeds 19.99%, the meltability deteriorates, mechanical properties decrease, devitrification resistance worsens, the liquidus temperature and transition temperature of the glass increase, and the specific gravity increases. Therefore, La 3+ The content is 12.0~19.99%, preferably 12.5~19.8%.

[0065] Zr 4+ It is an effective component for increasing the refractive index of optical glass. It also significantly increases the viscosity of glass during forming, improves the thermal conductivity, hardness, strength, and other mechanical properties of glass, reduces the coefficient of thermal expansion, and enhances the crack resistance of glass under temperature differences. Furthermore, it makes glass less prone to breakage during machining. By containing an appropriate amount, it can improve the glass's resistance to devitrification and chemical stability, especially its alkali resistance. On a molar percentage basis, if Zr... 4+ If the Zr content is below 2.0%, it will not have the desired effect; however, if the Zr content is below 2.0%, it will not have the desired effect. 4+ A Zr content exceeding 6.0% leads to poorer melting properties, increased melting temperature, decreased devitrification resistance, and increased transition temperature. Therefore, Zr... 4+ The content is 2.0~6.0%, preferably 2.5~5.5%.

[0066] Zn 2+ Zn has the function of regulating the refractive index and dispersion of glass. It is an effective component for lowering the melting temperature and transition temperature (Tg) of glass, improving the chemical stability of optical glass, and enhancing its resistance to devitrification and light transmittance. 2+ It is a glass intermediate, typically existing as a zinc-oxygen octahedron [ZnO6] as the network exterior oxide. When it captures free oxygen in the glass, it can form a zinc-oxygen tetrahedron [ZnO4] which enters the glass's structural network, making the glass structure more stable and thus improving its properties. This includes increasing the glass's strength, improving its crack resistance under temperature differences, and making it less prone to breakage during machining. In molar percentage terms, if Zn... 2+ If the Zn content is below 10.1%, it will not have the desired effect; however, if the Zn content is below 10.1%, it will not have the desired effect. 2+A Zn content exceeding 21.0% will cause the glass to fail to achieve the required refractive index, while also worsening its chemical stability, devitrification resistance, hardness, strength, and resistance to cracking under extreme temperature changes. Therefore, Zn... 2+ The content is 10.01~21.0%, preferably 10.5~20.5%.

[0067] Nb 5+ It is an effective component for improving the refractive index and dispersion of glass, and also improves the glass's resistance to devitrification and chemical stability. On a molar percentage basis, if Nb... 5+ When the Nb content exceeds 13.0%, the glass dispersion increases, the chemical stability and devitrification resistance decrease, the melt flowability deteriorates, and the specific gravity also increases. 5+ The high cost of raw materials increases the cost of glass, and the transmittance in the short wavelength range of visible light also decreases; if Nb 5+ If the Nb content is below 6.0%, the glass cannot achieve the required optical constants; therefore, Nb... 5+ The content is controlled at 6.0~13.0%, preferably 6.5~12.5%.

[0068] In this invention, Nb is expressed as a molar percentage. 5+ with La 3+ The ratio of Nb content 5+ / La 3+ The value should be not less than 0.415, preferably not less than 0.42, for example: 0.415~1. If Nb 5+ / La 3+ If the refractive index is too small, a high refractive index cannot be obtained. At the same time, the glass's resistance to devitrification, chemical stability, thermal conductivity, hardness, and strength will decrease to some extent, and its resistance to cracking under temperature differences will also decrease.

[0069] Ti 4+ Ti can significantly increase the refractive index and dispersion of glass, improve its resistance to devitrification and chemical stability, and also reduce its specific gravity. 4+As an intermediate oxide, a portion of TiO2 enters the structural network as titanium oxide tetrahedra [TiO4], participating in the formation of the glass network and making the glass structure more stable, thereby improving the glass's performance. This includes increasing the glass's hardness, strength, and other mechanical properties, reducing the coefficient of thermal expansion, and improving the glass's resistance to cracking under temperature differences. However, when the TiO2 content exceeds 13.0%, the glass's dispersion increases sharply, and the absorption in the short wavelength region of the visible light band (below 500 nm) is enhanced, leading to a significant reduction in transmittance, severe glass coloration, and a deterioration in devitrification resistance. If the TiO2 content is below 8.0%, the desired effect cannot be achieved, especially the required crack resistance. Therefore, the TiO2 content is 8.0~13.0%, preferably 8.5~12.5%.

[0070] In this invention, Ti is expressed as a molar percentage. 4+ The content of B 3+ The ratio of Ti content 4+ / B 3+ The value should not exceed 0.8, preferably not exceed 0.75, for example: 0.1~0.8. If Ti 4+ / B 3+ If the size is too large, titanium is easily reduced to Ti at high temperatures. 3+ This makes the glass easy to color, drastically reducing its transmittance. At the same time, it easily forms titanium oxide octahedrons [TiO6] outside the structural network, reducing the glass's resistance to devitrification, chemical stability, hardness, and strength, and decreasing its resistance to cracking under temperature differences.

[0071] In this invention, from the viewpoint of improving the glass refractive index and stability, reducing coloration, and suppressing the decrease in Abbe number, the Ti, in molar percentage... 4+ With Ti 4+ and Nb 5+ The ratio of the sum of the contents of Ti 4+ / (Ti 4+ +Nb 5+ The value is less than 0.6, preferably below 0.59, for example: 0.2~0.598.

[0072] In this invention, Zn is expressed as a molar percentage. 2+ Ti 4+ 、Nb 5+ The sum of the contents of La 3+ The ratio of content (Zn) 2+ +Ti 4 + +Nb 5+ ) / La 3+By controlling the coefficient of thermal expansion (CTE) to be not less than 1.62, preferably not less than 1.64, and for example, between 1.62 and 3.5, the glass of this invention exhibits excellent properties, namely a low coefficient of thermal expansion, a high thermal conductivity, and high hardness and strength, thereby improving the glass's resistance to cracking under temperature differences. It also possesses excellent chemical stability and resistance to devitrification, while effectively improving the glass's meltability, suppressing excessive rise in the glass transition temperature, and appropriately lowering the glass's melting temperature to achieve a suitable melting process, thereby improving the glass's colorability.

[0073] In this invention, from the viewpoint of maintaining glass stability, reducing specific gravity and transition temperature Tg, balancing hardness and strength, and suppressing the decrease in refractive index, La is expressed as a molar percentage. 3+ The content of Ti 4+ 、Nb 5+ The ratio of the sum of the contents of La 3+ / (Ti 4+ +Nb 5+ The content of La is not greater than 1.56, preferably not greater than 1.50, for example: 0.2~1.56. Further, in this invention, the content of La is expressed as a molar percentage. 3+ Gd 3+ Y 3+ Total content and Ti 4+ 、Nb 5+ The ratio of the sum of the contents of La 3+ +Gd 3+ +Y 3+ ) / (Ti 4+ +Nb 5+ The value should not exceed 1.56, preferably not exceed 1.50, for example: 0.2~1.56.

[0074] Sb 3+ As a commonly used clarifying agent, Sb is an effective component for eliminating air bubbles in glass. It combines with oxygen in the glass at low temperatures and releases oxygen at high temperatures, thus achieving a clarifying effect. 3+ If it exceeds 0.2%, glass tinting will lead to a decrease in light transmittance. Therefore, Sb 3+ The content is controlled at 0~0.2%, preferably 0.01~0.15%.

[0075] Other clarifying agents used in the glass industry can also be introduced to achieve degassing. The glass of this invention has good melt properties and bubbles are easily eliminated.

[0076] In the high refractive index optical glass of the present invention, Gd 3+ and Y 3+ It has similar properties to La in improving refractive index, hardness, and other properties. 3+ Similar effects. But contains Gd 3+The raw materials are expensive and have a high specific gravity, containing Y. 3+ The raw materials are also relatively expensive. A high total amount of rare earth elements such as La, Y, and Gd not only increases the melting temperature and thermal expansion coefficient of the optical glass of this invention, leading to poorer devitrification resistance, but also raises the glass transition temperature and sag temperature, and increases its specific gravity, which does not meet the requirements of lightweight and low cost. Therefore, under the premise of fully satisfying the excellent performance of the high-refractive-index optical glass of this invention, it is preferable not to add Gd in this invention. 3+ and Y 3+ .

[0077] Yb 3+ Rare earth elements have large atomic weights, which tend to increase the specific gravity of glass. Furthermore, they exhibit absorption in the near-infrared band, which is detrimental to improving glass transmittance; therefore, they are preferably not added in this invention.

[0078] Sn 4+ The presence of [something] will reduce the transmittance of the glass, therefore it is preferable not to add it in this invention.

[0079] Al 3+ The presence of [a substance] will reduce the meltability of the glass and worsen its devitrification resistance; therefore, it is preferable not to add [a substance] in this invention.

[0080] Introducing Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ While one or more of these substances may help improve the meltability of the optical glass of the present invention, they also deteriorate the network structure of the glass, reduce its hardness, and fail to achieve the expected optical constants. Therefore, it is preferable not to add them in the present invention.

[0081] Introducing Li + Na + K + 、Rb + Cs + While one or more of these substances may help improve the meltability of the optical glass of the present invention, they also deteriorate the glass's network structure, decrease its hardness, drastically increase its coefficient of thermal expansion, and worsen its chemical stability. At the same time, the refractive index decreases sharply, failing to reach the expected optical constant, and the glass's resistance to cracking under temperature differences deteriorates drastically. Therefore, it is preferable not to add these substances in the present invention.

[0082] The optical glass provided by this invention preferably does not artificially introduce expensive components such as Ge, Ga, Te, and Ta. Considering environmental impact, it does not introduce elements harmful to the environment and human health, such as Th, Cd, Pb, As, Hg, F, P, and Ba, nor does it contain elements such as Tl, Os, Be, Se, and Bi. To achieve excellent transmittance performance in the short-wavelength region, other coloring elements, such as transition metals like Nd, V, Mo, Cr, Mn, Fe, Co, Ni, Cu, Ag, and W, are not introduced.

[0083] The optical glass of this invention is particularly suitable for meeting the performance requirements of automotive lenses used in driving.

[0084] In this invention, the coefficient of thermal expansion α of the optical glass is... -30~70 Not greater than 60×10 -7 / K, preferably not greater than 56×10 -7 / K, for example: 50×10 -7 / K~60×10 -7 / K; the thermal conductivity λ of the optical glass is not less than 1.0 W / (m·K), preferably not less than 1.05 W / (m·K), for example: 1~1.5 W / (m·K).

[0085] In this invention, the specific gravity of the optical glass is no greater than 4.60 g / cm³. 3 Preferably, it is no more than 4.56 g / cm³. 3 For example: 4.30~4.60 g / cm³ 3 The Knoop hardness HK of the optical glass is 700 × 10⁻⁶. 7 Pa or higher, preferably 710 × 10 Pa 7 Pa or higher, for example: 700 × 10 7 ~760×10 7 Pa or higher; the bending strength σ of the optical glass b The pressure is 110 MPa or higher, preferably 115 MPa or higher, for example: 110~150 MPa.

[0086] In this invention, the optical glass described herein has a moisture resistance stability R. C Grade 1; Acid resistance stability R A Grade 1; Weather resistance stability C R Grade 1; Alkali resistance R (OH) S is grade 1; washability RP(S) is grade 1; water resistance D W (Powder method) Grade 1; Acid resistance D A (Powder method) is grade 2 or above, for example: grade 1 or grade 2.

[0087] In this invention, the tinting degree λ of the optical glass 70 λ in / λ5 70 The wavelength is below 425nm, preferably below 420nm, for example: 400~425nm; λ5 is below 365nm, preferably below 360nm, for example: 345~365nm.

[0088] In this invention, the transition temperature Tg of the optical glass is below 635°C, preferably below 630°C, for example: 600~635°C; the liquidus temperature L... T The temperature is below 1050°C, preferably below 1040°C, for example: 1000~1050°C.

[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 free of bubbles and foreign matter, or with few bubbles and foreign matter, and / or free of streaks or with few streaks.

[0090] According to the method for preparing optical glass of the present invention, in a preferred embodiment, it specifically includes the following steps: 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 1150-1200°C, homogenizing it for 2-6 hours, clarifying it at a temperature of 1250-1300°C for 2-6 hours to allow the bubbles to rise fully, then lowering the temperature of the glass melt to about 1100-1150°C, pouring it or leaking it through a cylindrical pipe into a forming mold, 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 of the present invention. Specifically, the plate-shaped optical glass provided by the present invention is cut into small pieces and then ground, heated, softened, pressurized and annealed to produce an optical element blank. The blank is then ground, polished and coated to obtain the optical element. Alternatively, the molded preform is precision molded to obtain a spherical or aspherical optical element.

[0092] After the optical glass of this invention is processed into optical elements, it is suitable for automotive lenses used in driving, and can also be widely used in digital cameras, video cameras, mobile phones, LCD projectors, telescopes, microscopes, copiers, laser printers, as well as optical lenses, prisms and other optical lenses for optical communication.

[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 1-43

[0096] The raw materials (SiO2, B2O3, La2O3, Nb2O5, TiO2, ZrO2, ZnO, Sb2O3, etc.) corresponding to each component in Examples 1-43 shown in Table 3-11 are weighed in proportion, mixed evenly to form a batch material, and then put into a platinum melting device for melting and stirring at a temperature of 1180°C. The mixture is then clarified at a temperature of 1280°C to allow the bubbles to rise fully. The temperature is then lowered to 1150°C for homogenization and pouring or spouting into a molding die for forming. Finally, the optical glass of the present invention is obtained after annealing.

[0097] Comparative Examples 1-2

[0098] The raw materials (SiO2, B2O3, La2O3, Nb2O5, Gd2O3, TiO2, ZrO2, ZnO, Sb2O3, etc.) corresponding to each component in Comparative Examples 1-2 shown in Table 11 were weighed in the prescribed proportions and prepared using the same preparation method as in Examples 1-43 to obtain the optical glass of Comparative Examples 1-2.

[0099] Performance testing

[0100] 1. The refractive index n of the obtained optical glass was tested 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 are for annealing at -4℃ / H.

[0101] 2. The glass transition temperature (Tg) of the obtained optical glass was determined according to the test method of GB / T7962.16-2010, and the coefficient of thermal expansion (α) was also measured. -30~70 The determination.

[0102] 3. Place the glass sample in a gradient furnace and hold it at different temperatures for 1 hour each. Observe the crystallization inside the glass sample using a microscope to determine the liquidus temperature L. T .

[0103] 4. The specific gravity of the obtained optical glass was determined according to the test method of GB / T7962.20-2010.

[0104] 5. The hardness of the obtained optical glass shall be measured according to the test method of GB / T7962.18-2010.

[0105] 6. Bending strength σ b Measurement of (MPa)

[0106] The fracture load of a finely annealed and polished specimen is tested using the "three-point bending test" method, and the bending strength is calculated using the following formula.

[0107]

[0108] Where: P—fracture load, N;

[0109] L—span distance, mm;

[0110] w—width, mm;

[0111] t — thickness, mm.

[0112] 7. Shading degree λ 70 / λ5

[0113] The short-wavelength transmission spectral characteristics of optical glass are expressed using colorimetric λ. 70 / λ5 represents λ. 70 λ5 refers to the wavelength corresponding to a glass transmittance of 70%, while λ5 refers to the wavelength corresponding to a glass transmittance of 5%. The light transmittance of a glass with a thickness of 10 ± 0.1 mm, ground on parallel surfaces, was measured according to the Japan Glass Industry Association's "Method for Measuring the Colorimetric Index of Optical Glass" JOGIS02.

[0114] 8. The surface moisture resistance R of the obtained optical glass was tested according to the test method of GB / T7962. C Surface method acid resistance R A .

[0115] 9. The weathering stability C of the obtained optical glass was tested according to the test method of GB / T7962. R .

[0116] 10. The water resistance of the obtained optical glass was tested according to the test method of GB / T17129. W Acid resistance D A Conduct the test.

[0117] 11. Alkali resistance R OH (S) (Surface Method) Measurement

[0118] A 40×40×5mm 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 R of optical glass OH (S) is divided into five levels, as shown in Table 1 below.

[0119] Table 1: Alkali Resistance Grades of Optical Glass

[0120]

[0121] 12. Measurement of Washability RP(S) (Surface Method)

[0122] 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 •h), the washability RP(S) of optical glass is divided into five levels, as shown in Table 2 below:

[0123] Table 2: Washability rating of optical glass

[0124]

[0125] 13. The thermal conductivity λ of the obtained optical glass was tested according to the test method of GB / T7962.13-2010.

[0126] 14. Evaluate the crack resistance of glass under temperature differences according to the method described below.

[0127] Prepare 100 round, flat lenses with a diameter of ￠20mm × 6mm, after fine polishing and refining. No surface defects such as cracks or chipped edges are allowed. Place all 100 lenses in a 100℃ constant temperature chamber for 30 minutes. Quickly remove them and place them in ice water at 0℃-3℃ for 5 minutes. After quickly removing and drying the lenses, observe them under a 27W fluorescent lamp for any cracks. Repeat the above steps for lenses that do not show cracks. Perform five rounds of hot and cold temperature difference tests. Count the total number of lenses that eventually develop cracks and calculate the integrity rate.

[0128] A glass with an integrity rate of 95% or higher is considered to have good crack resistance, while a rate below 95% is considered to have poor crack resistance.

[0129] The refractive index n of the optical glass prepared in Examples 1-43 d Abbe number υ dGlass transition temperature Tg, coefficient of thermal expansion α -30~70 Specific gravity ρ, Knoop hardness HK, flexural strength σ b , shading degree λ 70 / λ5, Liquidus temperature L T Surface method moisture resistance stability R C Surface method acid resistance R A Powder method water resistance stability D W Powder method acid resistance D A Alkali resistance R OH (S), washability RP(S), weather stability C R The crack resistance is listed in Table 3-11. The measured data from Comparative Examples 1-2 are listed in Table 11. The components in the tables are expressed as a cation molar percentage, or cat%.

[0130] Table 3: Glass composition and performance parameters of Examples 1-5

[0131]

[0132] Table 4: Glass composition and performance parameters of Examples 6-10

[0133]

[0134] Table 5: Glass composition and performance parameters of Examples 11-15

[0135]

[0136] Table 6: Glass composition and performance parameters of Examples 16-20

[0137]

[0138] Table 7: Glass composition and performance parameters of Examples 21-25

[0139]

[0140] Table 8: Glass composition and performance parameters of Examples 26-30

[0141]

[0142] Table 9: Glass composition and performance parameters of Examples 31-35

[0143]

[0144] Table 10: Glass composition and performance parameters of Examples 36-40

[0145]

[0146] Table 11: Glass composition and performance parameters of Examples 41-43 and Comparative Examples 1-2

[0147]

[0148] As can be seen from Tables 1-11, the optical glasses of Examples 1-43 of the present invention exhibit excellent crack resistance. The coefficient of thermal expansion α of the optical glass... -30~70 Low, specifically 50×10 -7 / K~60×10 -7 / K; Optical glass has a high thermal conductivity λ, specifically 1~1.5 W / (m·K). Glass has a low specific gravity, specifically 4.30~4.60 g / cm³. 3 The optical glass has a high Knoop hardness (HK), specifically 700 × 10⁻⁶. 7 ~760×10 7 Pa or higher; the bending strength σ of the optical glass b The pressure is high, specifically 110~150 MPa. Additionally, the transition temperature (Tg) of optical glass is 600~635℃; the liquidus temperature (L) is... T Temperature range: 1000~1050℃, chromaticity λ 70 λ in / λ5 70 Below 425nm, λ5 is below 365nm.

[0149] The optical glasses of Examples 1-43 exhibit excellent chemical stability and moisture resistance R. C Grade 1, acid resistance stability R A (Surface method) Grade 1, weather resistance stability C R Grade 1, alkali resistance R (OH) S (surface method) is grade 1, washability RP(S) is grade 1, water resistance D W (Powder method) Grade 1, acid resistance D A (Powder method) is grade 2 or above, for example: grade 1 or grade 2.

[0150] However, Comparative Example 1 contained excessive La. 3+ But Zn 2+ The content is too low, and it contains Gd. 3+ This results in poor crack resistance and a low coefficient of thermal expansion α. -30~70 Too high, high density, bending strength σ b Low, the transition temperature and liquidus temperature are too high, and the color intensity λ is low. 70 λ in / λ5 70 Too high. Comparative Example 2 contained excessive La. 3+ But Ti 4+The content is too low, resulting in poor crack resistance and low coefficient of thermal expansion α. -30~70 It has too high a temperature, high density, low hardness and flexural strength, and excessively high transition temperature and liquidus temperature.

[0151] 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.

[0152] 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, The optical glass contains the following components by mole percentage: Si 4+ : 5.0~13.0%, preferably 5.5~12.5%; B 3+ : 24.5~45.0%, preferably 25.0~44.5%; La 3+ : 12.0~19.99%, preferably 12.5~19.8%; Nb 5+ : 6.0~13.0%, preferably 6.5~12.5%; Ti 4+ : 8.0~13.0%, preferably 8.5~12.5%; Zr 4+ : 2.0~6.0%, preferably 2.5~5.5%; Zn 2+ : 10.01~21.0%, preferably 10.5~20.5%; Sb 3+ : 0~0.2%, preferably 0.01~0.15%; The refractive index n of the optical glass d An Abbe number of υ is above 1.

89. d It is 28 or above.

2. The optical glass according to claim 1, characterized in that, In molar percentage, Ti 4+ With Ti 4+ and Nb 5+ The ratio of the sum of the contents of Ti 4+ / (Ti 4+ +Nb 5+ The value is less than 0.6, preferably less than 0.59; Zn 2+ Ti 4+ 、Nb 5+ The sum of the contents of La 3+ The ratio of Zn content 2+ +Ti 4+ +Nb 5+ ) / La 3+ The value should be no less than 1.62, preferably no less than 1.

64.

3. The optical glass according to claim 1 or 2, characterized in that, Nb in mole percentage 5+ with La 3+ The ratio of Nb content 5+ / La 3+ It should be no less than 0.415, preferably no less than 0.42; La 3+ The content of Ti 4+ and Nb 5+ The ratio of the sum of the contents of La 3+ / (Ti 4+ +Nb 5+ The value should not exceed 1.56, preferably not exceed 1.

50.

4. The optical glass according to any one of claims 1-3, characterized in that, In molar percentage, Ti 4+ With B 3+ The ratio of Ti content 4+ / B 3+ The value should not exceed 0.8, and preferably should not exceed 0.

75. In mole percentage, B 3+ With Si 4+ The ratio of the content of B 3+ / Si 4+ It should be greater than 1.0, preferably greater than 1.1; In mole percentage, B 3+ With Si 4+ The sum of the contents of B 3+ +Si 4+ The content is 30.0% to 60.0%, preferably 31.0% to 59.0%.

5. The optical glass according to any one of claims 1-4, characterized in that, The optical glass does not contain Gd. 3+ Y 3+ Yb 3 + Sn 4+ Al 3+ Mg 2+ Ca 2+ 、Sr 2+ Ba 2+ Li + Na + K + 、Rb + Cs + One or more combinations of the above.

6. The optical glass according to any one of claims 1-5, characterized in that, The coefficient of thermal expansion of the optical glass is α -30~70 Not greater than 60×10 -7 / K; The thermal conductivity λ of the optical glass is not less than 1.0 W / (m·K).

7. The optical glass according to any one of claims 1-6, characterized in that, The density of the optical glass is no greater than 4.60 g / cm³. 3 ; The Knoop hardness H of the optical glass K 700×10 7 Pa or above; The bending strength σ of the optical glass b It is above 110 MPa.

8. The optical glass according to any one of claims 1-7, characterized in that, The tinting degree λ of the optical glass 70 λ in / λ5 70 Below 425nm, λ5 is below 365nm; The transition temperature Tg of the optical glass is below 635℃; Liquidus temperature L T Below 1050℃.

9. A method for preparing optical glass according to any one of claims 1-8, 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. A vehicle-mounted lens, characterized in that, Includes the optical glass according to any one of claims 1-8.

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