Optical glass, its preparation method and optical components

Abstract

This invention provides an optical glass, its preparation method, and an optical element. The optical glass contains the following components in molar percentage: B₂O₃: 5.0%–19.9%; SiO₂: 5.0%–28.0%; La₂O₃: 0.05%–11.5%; Gd₂O₃: 0%–10.0%; Y₂O₃: 3.6%–15.0%; ZnO: 22.5%–60.0%; the refractive index n of the optical glass is... d An Abbe number of υ is above 1.78. d The temperature coefficient of refractive index is 35-45. The optical glass of this invention has a large positive temperature coefficient of refractive index. When used in combination with optical glass having a negative temperature coefficient of refractive index, it can effectively correct temperature drift caused by rapid temperature changes or high-temperature environments, fix the focus, and maintain clear imaging. It is suitable for vehicle-mounted cameras or projectors, copiers, laser printers, and playback devices that generate a lot of heat during use.

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, with the booming development of the new energy vehicle industry, intelligent driving systems have also been continuously upgraded and replaced, and intelligent driving is increasingly and deeply entering our daily lives. An intelligent driving car requires a large number of visual assistance systems, such as reversing cameras, front-view cameras, and rearview mirror auxiliary cameras.

[0003] However, compared to general photography applications like smartphones and SLR cameras, the quality of automotive lenses is directly related to safety. For automobiles, safety is paramount, so automotive lenses place a greater emphasis on reliability, requiring designs that can withstand harsh working environments and have a lifespan of over ten years. Lenses exposed on the vehicle's exterior, in particular, need to withstand harsh environments such as significant temperature differences between day and night, north-south temperature variations, acid rain, gravel erosion, impacts, and extreme weather conditions like strong typhoons. This necessitates that automotive cameras maintain clear imaging even under rapidly changing temperature conditions; and the optical glass used must possess excellent bending strength, chemical stability, and light transmittance to meet the long-term safety and reliability requirements of intelligent driving.

[0004] In addition to in-vehicle cameras, projectors, copiers, laser printers, and imaging devices increasingly entering homes generate significant heat during use. These devices are prone to image blurring due to temperature variations. Therefore, there is a need to develop optical glass with specific refractive index temperature coefficients, such as glass with a large positive refractive index temperature coefficient, to create an optical system that maintains clear imaging even under significant temperature changes in the optical components.

[0005] In the prior art, a refractive index (n) of 1.78 or higher is used. d ), 35-45 Abbe number (υ d Optical glass with a high refractive index temperature coefficient (rn) has a wide range of applications in optical design and is widely used in various lenses. However, it suffers from various problems, such as a generally low refractive index temperature coefficient, low bending strength, poor chemical stability, or a high transition temperature unsuitable for precision molding, failing to meet the requirements of lenses used in automotive, projection, and other applications. Therefore, there is an urgent need to develop optical glass with a high positive refractive index temperature coefficient and bending strength, good chemical stability and transmittance, excellent devitrification resistance, a low transition temperature suitable for precision molding, and low production cost. d An Abbe number of υ is above 1.78. d The value is 35-45.

[0006] Patent application CN114085036A discloses an optical glass with a refractive index n d The Abbe number is υ, which ranges from 1.82 to 1.86. d The glass composition, expressed as a percentage by weight, is 42.06-46, containing: B2O3: 5-25%; SiO2: 1-15%; La2O3: 30-50%; Gd2O3: 4-20%; Y2O3: 2-15%; Ta2O5: 0-15%; ZrO2: 0.71-8%; and the ratio of Y2O3 / (La2O3+Gd2O3+Y2O3) is 0.03-0.3. The glass in this patent application contains the expensive raw material Ta2O5, resulting in high production costs. Furthermore, its crystallization temperature exceeds 1180℃, leading to poor crystallization performance and hindering production.

[0007] Patent application CN110937802A discloses an optical glass with a refractive index n d The Abbe number is υ, which is between 1.75 and 1.85. d The glass content is 34-40%, and its composition, expressed as a weight percentage, contains: SiO2+B2O3: 8-40%; La2O3: 15-40%; Nb2O5: 2-24%; BaO: 18-45%, of which the La2O3 / BaO ratio is 0.5-2.0. The glass in this patent application contains a relatively high amount of BaO, resulting in a higher glass density, poorer chemical stability, and an inability to achieve a high refractive index temperature coefficient. Summary of the Invention

[0008] The problem the invention aims to solve

[0009] In view of the technical problems existing in the prior art, the present invention first provides an optical glass with a large positive refractive index temperature coefficient and bending strength, the refractive index n d Above 1.78, the Abbe number υ d With a pH of 35-45, it exhibits good chemical stability and permeability, a low transition temperature suitable for precision molding, low density, good resistance to devitrification, low production cost, suitability for mass production, and excellent internal product quality.

[0010] Furthermore, the present invention also provides a method for preparing optical glass with readily available raw materials, simple preparation steps, and excellent process performance.

[0011] Furthermore, the present invention also provides an optical element of the optical glass of the present invention.

[0012] Solution for solving the problem

[0013] This invention provides an optical glass, wherein the optical glass contains the following components in mol%:

[0014] B2O3: 5.0%–19.9%, preferably 6.0%–19.5%;

[0015] SiO2: 5.0%–28.0%, preferably 6.0%–25.0%;

[0016] La2O3: 0.05%–11.5%, preferably 0.5%–11.0%;

[0017] Gd2O3: 0%–10.0%, preferably 0%–8%;

[0018] Y2O3: 3.6%–15.0%, preferably 4.0%–14.0%;

[0019] ZnO: 22.5%–60.0%, preferably 23.0%–58.0%;

[0020] The refractive index n of the optical glass d An Abbe number of υ is above 1.78. d The value is 35-45.

[0021] According to the optical glass of the present invention, the optical glass further comprises, in mole percent, the following components: ZrO2: 0%–6.0%; and / or, Nb2O5: 0%–3.0%; and / or, TiO2: 0%–3.0%; and / or, R2O: 0%–2%; and / or, WO3: 0%–5.0%; and / or, Al2O3: 0%–5.0%; and / or, SnO2: 0%–1.0%; and / or, Sb2O3: 0%–1.0%; wherein,

[0022] The R2O is one or a combination of two or more of Li2O, Na2O, and K2O.

[0023] According to the optical glass of the present invention, the ratio of Y₂O₃ to B₂O₃ content, Y₂O₃ / B₂O₃, is not less than 0.236, preferably not less than 0.30, in mol%; and / or

[0024] In mol% terms, the ratio of the content of Y2O3 to the sum of the contents of La2O3, Gd2O5 and Y2O3, Y2O3 / (La2O3+Gd2O3+Y2O3), is not less than 0.41, preferably not less than 0.45.

[0025] According to the optical glass of the present invention, the content ratio of ZnO to La2O3 (ZnO / La2O3) is not less than 5.2, preferably not less than 5.3, in mol%; and / or,

[0026] The ratio of ZnO to B2O3 content (in mole percent) is not less than 2.0, preferably not less than 2.3; and / or,

[0027] The content ratio of B2O3 to SiO2, expressed as mol%, is 0.2 to 3.0, preferably 0.25 to 2.8.

[0028] According to the optical glass of the present invention, the ratio of the sum of the contents of Nb2O5, TiO2, ZrO2 and WO3 to the sum of the contents of SiO2 and B2O3 (Nb2O5+TiO2+ZrO2+WO3) / (SiO2+B2O3) is 0.12 to 1.0, preferably 0.14 to 0.9, in mol%.

[0029] According to the optical glass of the present invention, the relative refractive index temperature coefficient dn / dt of the optical glass at 40–60°C is 8.0 × 10⁻⁶. -6 / ℃ or above, preferably 8.5×10 -6 / ℃ or above; and / or,

[0030] The optical glass has a bending strength of 90 MPa or higher, preferably 100 MPa or higher.

[0031] According to the optical glass of the present invention, the moisture resistance stability R of the optical glass is... C Grade 1; Acid resistance stability R A Grade 1; Alkali resistance R (OH) S is grade 1; washability RP(S) is grade 1; and / or,

[0032] The wavelength λ of optical glass with a thickness of 10 mm and a transmittance of 80% 80 The wavelength λ5 of the optical glass with a thickness of 10 mm and a transmittance of 5% is 398 nm or less, preferably 395 nm or less.

[0033] The optical glass according to the present invention, wherein the optical glass has at least one of the following characteristics:

[0034] The transition temperature T of the optical glass g The temperature should be below 605℃, preferably below 600℃;

[0035] The liquidus temperature L of the optical glass T The temperature should be below 1000℃, preferably below 990℃;

[0036] The density of the optical glass is 4.80 g / cm³. 3 The preferred value is 4.75 g / cm³. 3the following.

[0037] The present invention also provides a method for preparing optical glass according to the present invention, which includes the step of mixing the components of the optical glass.

[0038] The present invention also provides an optical element comprising the optical glass described in the present invention.

[0039] The effects of the invention

[0040] The optical glass of this invention has a large positive refractive index temperature coefficient. When used in combination with optical glass having a negative refractive index temperature coefficient, it can effectively correct temperature drift caused by rapid temperature changes or high-temperature environments, fix the focus, and maintain clear imaging. It is suitable for vehicle-mounted cameras or projectors, copiers, laser printers, and playback devices that generate a lot of heat during use.

[0041] Meanwhile, the optical glass of this invention has high bending strength, low production cost, excellent transmittance and chemical stability, and excellent devitrification resistance. It is a glass material with very good performance and has a wide range of applications in optical design.

[0042] 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

[0043] 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.

[0044] 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.

[0045] 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.

[0046] In this specification, the word "may" has two meanings: to perform a certain process and not to perform a certain process.

[0047] 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.

[0048] 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.

[0049] In this instruction manual, when "room temperature" or "room temperature" is used, the temperature can be between 10-40℃.

[0050] The composition of the optical glass of the present invention will be described in detail below. The raw materials are introduced in various forms using compounds capable of introducing the corresponding component content. In this specification, unless otherwise specified, the content of each component and the total content are all expressed as a molar percentage relative to the total amount of glass material converted to oxides. Furthermore, in the following description, references to values ​​below or above a specified value also include those specified values.

[0051] The refractive index n of the optical glass of the present invention d The value should be 1.78 or higher, preferably 1.78-2; Abbe number υ d The value is 35–45. The specific descriptions of the necessary and arbitrary components are as follows:

[0052] B₂O₃ is an essential component for forming the glass network structure, effectively improving the glass's flexural strength, devitrification resistance, melting performance, chemical stability, and reducing the glass transition temperature. If the B₂O₃ content is higher than 19.9%, the glass's refractive index decreases, its chemical stability deteriorates, and its viscosity decreases, increasing the difficulty of forming. If the B₂O₃ content is lower than 5.0%, the Abbe number is difficult to increase, melting performance deteriorates, and the effect on improving flexural strength is not significant enough. The glass transition temperature (Tg) is also affected. g The concentration of B2O3 will increase, resulting in poorer devitrification resistance. Therefore, the content of B2O3 component is 5.0%–19.9%, preferably 6.0%–19.5%.

[0053] SiO2 is an essential component for forming the glass network structure, effectively improving the glass's devitrification resistance, hardness, and chemical stability, especially acid resistance. It also effectively increases the viscosity of the glass at high temperatures and during forming, making it easier to form and suitable for stable mass production, thus improving the yield rate of each production process. If the SiO2 content is higher than 28.0%, the glass's melting properties deteriorate, the transition temperature increases, and the refractive index decreases. If the SiO2 content is lower than 5.0%, the devitrification resistance and chemical stability will be poor. Therefore, the SiO2 content is 5.0%–28.0%, preferably 6.0%–25.0%.

[0054] In this invention, when the B2O3 / SiO2 content ratio (B2O3 / SiO2) is too high (in molar percentage), the glass's devitrification resistance decreases, its chemical durability deteriorates, and especially its acid resistance worsens. When the B2O3 / SiO2 content ratio is too low, the glass's meltability deteriorates, and its transition point increases. When the B2O3 / SiO2 content ratio is appropriate, higher flexural strength and refractive index temperature coefficient can also be obtained. Therefore, in this invention, the B2O3 / SiO2 content ratio is 0.2–3.0, preferably 0.25–2.8.

[0055] La₂O₃ is an essential component in the formation of the glass of this invention, improving the glass's refractive index and Abbe number, and playing a crucial role in enhancing chemical stability and devitrification resistance. Furthermore, compared to other rare earth raw materials with similar functions, La₂O₃ is relatively inexpensive, and its appropriate use can reduce the material cost of the glass. When the La₂O₃ content exceeds 11.5%, the solubility and devitrification resistance deteriorate, and the glass transition temperature increases. Therefore, the La₂O₃ content is 0.05% to 11.5%, preferably 0.5% to 11.0%.

[0056] In the optical glass of this invention, Gd₂O₃ has a similar effect to La₂O₃, increasing the glass's refractive index and Abbe number, while also contributing to improved chemical stability and devitrification resistance. However, Gd₂O₃ is expensive; a higher content would significantly increase production costs, glass density, and glass transition temperature. Therefore, the Gd₂O₃ content of this invention is limited to 0–10%, preferably 0–8%.

[0057] Y₂O₃ improves the refractive index and Abbe number of glass, and plays an important role in improving chemical stability and devitrification resistance. Compared to Gd₂O₃, Y₂O₃ is cheaper, and its appropriate use can reduce the material cost of glass. Furthermore, compared to other rare earth elements, it can reduce the specific gravity of glass. When the amount introduced exceeds 15%, the devitrification resistance of the glass decreases, the liquidus temperature increases, and the solubility of the glass raw material deteriorates. When the Y₂O₃ content is below 3.6%, the refractive index decreases, dispersion tends to increase, making it difficult to obtain the optical constants of this invention, and its effect on improving chemical stability is not significant. Therefore, the Y₂O₃ content is 3.6% to 15.0%, preferably 4.0% to 14.0%.

[0058] In this invention, Y2O3 and B2O3 exist in combination. When the content ratio of Y2O3 to B2O3, Y2O3 / B2O3, is controlled to be not less than 0.236, preferably not less than 0.30, in molar percentage, the refractive index temperature coefficient and bending strength of the glass can be effectively improved, as well as the devitrification resistance and chemical stability of the glass.

[0059] In this invention, La2O3, Gd2O3, and Y2O3 are all rare earth oxides that effectively improve the refractive index and reduce dispersion. When the ratio of the content of Y2O3 to the sum of the contents of La2O3, Gd2O5, and Y2O3 (Y2O3 / (La2O3+Gd2O3+Y2O3)) is controlled to be not less than 0.41, preferably not less than 0.45 (in mol%), the optical constants required by this invention can be obtained while effectively reducing the specific gravity and upper limit temperature of glass crystallization, improving the meltability and devitrification resistance of glass, enhancing its chemical stability, flexural strength, and refractive index temperature coefficient, and making it easier to produce products with good bubble characteristics and excellent striations.

[0060] ZnO can effectively increase the meltability of glass, improve its transmission performance, reduce coloration, and effectively lower the melting temperature, liquidus temperature, and transition temperature (T0) of glass. g This improves the devitrification resistance and chemical stability of the glass, and increases the temperature coefficient of refractive index and flexural strength. In this invention, when the content is less than 22.5%, the above effects are insufficient, while if the content is higher than 60.0%, the chemical stability and devitrification resistance of the glass deteriorate, and the high-temperature viscosity is low, making molding difficult. Therefore, the ZnO content is 22.5% to 60.0%, preferably 23.0% to 58.0%.

[0061] In this invention, when the ratio of ZnO to La2O3 content (in mole percent) is not less than 5.2, preferably not less than 5.3, it can effectively improve the colorimetric properties of the glass, reduce the transition temperature, and also improve the temperature coefficient of refractive index and bending strength of the glass, as well as improve its devitrification resistance and chemical stability.

[0062] In this invention, when the ZnO / B2O3 content ratio (in molar percentage) is controlled to be not less than 2.0, preferably not less than 2.3, a higher refractive index can be obtained, effectively improving the glass's refractive index temperature coefficient and flexural strength, as well as its devitrification resistance and chemical stability. The glass exhibits good melting properties and excellent processing performance, making it easier to produce products with good bubble and striation characteristics. Furthermore, the viscosity in the forming zone is suitable, and the low transition temperature is suitable for precision molding.

[0063] Nb₂O₅ improves the refractive index of glass, enhances its resistance to devitrification, and improves its chemical stability. However, when the Nb₂O₅ content exceeds 3.0%, the glass dispersion increases, the Abbe number decreases, and the required optical constant cannot be achieved. Simultaneously, the resistance to devitrification decreases, increasing the material cost of the glass. Furthermore, the transmittance in the visible light band (especially visible light with wavelengths below 500 nm) also decreases. Therefore, the Nb₂O₅ content is typically 0%–3.0%, preferably 0.2%–2.5%.

[0064] TiO2 strongly enhances the refractive index and dispersion of glass, and participates in glass network formation, thereby improving the flexural strength, devitrification resistance, and chemical stability of the glass, while also reducing its density. However, when the TiO2 content exceeds 3.0%, the dispersion of the glass increases dramatically, and the absorption of the glass in the short wavelength region of the visible light band (below 500 nm) is enhanced, leading to a severe decrease in transmittance, severe glass coloration, and a deterioration in devitrification resistance. Therefore, the TiO2 content is 0%–3.0%, preferably 0.2%–2.5%.

[0065] WO3 improves the refractive index and flexural strength of glass, enhances chemical stability and devitrification resistance, and lowers the glass transition point. However, when the WO3 content exceeds 5.0%, the dispersion of the glass increases sharply, devitrification resistance deteriorates, and the transmittance of the glass in the short wavelength range of the visible light spectrum (below 500 nm) is severely reduced, resulting in significant glass coloration. The WO3 content is 0%–5.0%, preferably 0.2%–4.5%.

[0066] ZrO2 can improve the refractive index, hardness, and devitrification resistance of glass, and can improve chemical stability, especially significantly improving the glass's washability (RP(S)) and alkali resistance (R). OH (S) The effect on the water resistance and mechanical properties of glass. When the ZrO2 content is higher than 6.0%, the melting temperature increases, the melting performance decreases, the devitrification tendency of the glass increases, and the transition temperature rises. Therefore, the ZrO2 content in this invention is 0% to 6.0%, preferably 0.5% to 5.5%.

[0067] In this invention, the ratio of the sum of the contents of Nb2O5, TiO2, ZrO2, and WO3 to the sum of the contents of SiO2 and B2O3 (Nb2O5+TiO2+ZrO2+WO3) / (SiO2+B2O3) is controlled to be 0.12-1.0, preferably 0.14-0.9. When this ratio is in mol%, the glass has good melting performance, which can effectively improve the colorimetric properties, devitrification resistance, and chemical stability of the glass, and obtain a higher refractive index temperature coefficient and bending strength. It is also easier to produce products with good bubble quality and excellent striations.

[0068] Al₂O₃ can improve the chemical stability of optical glass, especially its acid resistance, and can also improve its devitrification resistance and flexural strength. However, when its content exceeds 5%, the refractive index of the glass decreases, dispersion increases, and its melt properties and devitrification resistance deteriorate. Therefore, the Al₂O₃ content in this invention is 0–5%, preferably 0.5–4.0%.

[0069] R2O can be any component. This invention can also appropriately add one or more combinations of Li2O, Na2O, and K2O to improve the glass's meltability, lower the glass transition temperature, and enhance its devitrification resistance. However, when its content exceeds 2%, the glass's devitrification resistance and chemical stability decrease, and the refractive index and refractive index temperature coefficient decrease significantly, making it difficult to obtain a high refractive index temperature coefficient. Therefore, the R2O content in this invention is 0–2%, preferably 0–1.8%.

[0070] In this invention, when R2O is a combination of Li2O, Na2O, and K2O, the above-mentioned content range needs to be met based on their total content, and the content of each of Li2O, Na2O, and K2O can be 0 to 2%, preferably 0 to 1.8%.

[0071] SnO2 is an effective component for eliminating bubbles in glass. It combines with oxygen in the glass at low temperatures and releases oxygen at high temperatures, thus achieving a clarifying effect. When the SnO2 content exceeds 1.0%, the dispersion of the glass increases sharply, its devitrification resistance deteriorates, and the glass becomes further colored. Therefore, the SnO2 content can be 0–1%, preferably 0.01–0.9%.

[0072] Sb₂O₃ is an effective component for eliminating bubbles in glass. It combines with oxygen in the glass at low temperatures and releases oxygen at high temperatures, thus achieving a clarifying effect. However, if the Sb₂O₃ content exceeds 1%, the glass coloration will increase, and it will easily damage the surface of the forming mold, which is detrimental to precision molding. Therefore, the Sb₂O₃ content is controlled at 0%–1.0%, preferably 0.01%–0.9%.

[0073] This invention can also incorporate other clarifying agents used in the glass industry to achieve defoaming.

[0074] The glass of the present invention has good solubility and bubbles are easy to eliminate. Even without the introduction of a clarifying agent, glass with few or no bubbles can be obtained.

[0075] The optical glass of this invention can solve the problem of unclear imaging caused by temperature differences and can withstand the harsh working environment outside the vehicle body. The relative refractive index temperature coefficient dn / dt of the optical glass at 40-60℃ is 8.0×10⁻⁶. -6 Above / ℃, the preferred dn / dt is 8.5×10 -6 / ℃ or higher. Furthermore, the bending strength of the optical glass is 90 MPa or higher, preferably 100 MPa or higher.

[0076] In this invention, the prerequisite for stable mass production is that the glass has a low liquidus temperature. When the devitrification resistance of the glass decreases, its liquidus temperature rises sharply, and the stability of the glass deteriorates. Therefore, the liquidus temperature of the optical glass of this invention is controlled below 1000°C, preferably below 990°C or lower.

[0077] Furthermore, the optical glass of the present invention has a low transition temperature and a correspondingly low softening temperature, enabling stable mass production and precision molding. The transition temperature T of the optical glass of the present invention is... g The temperature should be below 605℃, preferably below 600℃ or lower.

[0078] Furthermore, the optical glass of the present invention exhibits excellent chemical stability and water resistance stability R. C Grade 1, acid resistance stability R A Grade 1, alkali resistance R (OH) S is grade 1, and the washability RP(S) is grade 1; the density of the optical glass is 4.80 g / cm³. 3 The preferred value is 4.75 g / cm³. 3 the following.

[0079] Furthermore, the wavelength λ of optical glass with a thickness of 10 mm and a transmittance of 80% is... 80 The wavelength λ5 of the optical glass with a thickness of 10 mm and a transmittance of 5% is 398 nm or less, preferably 395 nm or less.

[0080] The optical glass provided by this invention preferably does not artificially introduce expensive components such as GeO2, Ga2O3, TeO2, Yb2O3, and Ta2O5. Considering environmental impact, it does not introduce elements harmful to the environment and human health, such as Th, Cd, Pb, As, Hg, and F, nor does it contain elements such as Tl, Os, Be, Se, and Bi. To achieve the excellent transmittance performance of the optical glass in the short-wavelength region, it does not introduce other coloring elements, such as transition metal elements like Nd, V, Mo, Cr, Mn, Fe, Co, Ni, Cu, and Ag.

[0081] This invention also provides a method for preparing optical glass according to the invention, comprising the steps of weighing and mixing the components of the optical glass in a specified proportion. The resulting batch is then melted, stirred, clarified, and homogenized, and subsequently poured or cast into a molding die, or directly pressed to obtain optical glass. The obtained optical glass has few bubbles and foreign matter and / or shallow streaks, and further possesses superior internal quality, i.e., free of bubbles, foreign matter, and / or streaks.

[0082] According to the method for preparing optical glass according to 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 platinum melting apparatus, melting at a temperature of 1150°C to 1250°C, homogenizing for 2 to 6 hours, clarifying at a temperature of 1250°C to 1350°C for 2 to 6 hours to allow the bubbles to rise fully, then lowering the temperature of the glass melt to below 1150°C, pouring or leaking through a cylindrical pipe into a forming mold or molding by compression molding, and finally annealing to obtain the plate-shaped optical glass of the present invention.

[0083] The preparation method provided by the present invention has simple preparation steps, excellent process performance, and low production cost. The glass of the present invention has good meltability, low melting temperature, short refining time, and minimal glass erosion of the platinum crucible, thus avoiding a decrease in transmittance in the visible light region and facilitating the production of glass with good transmittance as described in the present invention.

[0084] The present invention also provides a preform for precision molding, comprising optical glass according to the present invention, which can be used for precision molding of spherical and aspherical surfaces.

[0085] 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.

[0086] The optical glass of this invention, after being processed into optical elements, can be widely used in vehicle lenses such as reversing cameras, front-view cameras, and rearview mirror auxiliary cameras; optical lenses in projectors, copiers, laser printers, and imaging devices for playback; and also in optical lenses such as lenses and prisms for digital cameras, camcorders, mobile phones, telescopes, microscopes, and optical communication. This allows for the miniaturization and lightweighting of optical lenses, while maintaining high reliability and high-definition image quality.

[0087] Example

[0088] 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.

[0089] 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.

[0090] Examples 1-40

[0091] The raw materials corresponding to each component in Examples 1-40 shown in Tables 3-8 were weighed and mixed evenly to prepare a compound. The compound was then put into a platinum melting apparatus and melted, stirred, and homogenized at 1200°C for about 4 hours. It was then clarified at 1300°C for about 4 hours to allow the bubbles to rise fully. The temperature was then lowered to 1120°C and poured into a molding mold to form the glass. Finally, after annealing, the plate-shaped optical glass of the present invention was obtained.

[0092] Comparative Examples 1-2

[0093] The raw materials corresponding to each component in Comparative Examples 1-2 shown in Table 8 were weighed according to the proportions and prepared using the same preparation method as in Examples 1-40 to obtain the optical glass of Comparative Examples 1-2.

[0094] Performance testing

[0095] 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 dThe measurement, n listed in the table d υ d The data are for annealing at -4℃ / H.

[0096] 2. According to the method specified in GB / T7962.4—2010, test the relative refractive index temperature coefficient (dlinedn / dtrelative(102) of optical glass in the range of 40–60℃. -6 / ℃)).

[0097] 2. The glass transition temperature T of the obtained optical glass was determined according to the test method of GB / T7962.16-2010. g Measurement.

[0098] 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 .

[0099] 4. Measure the density of the obtained optical glass according to the test method of GB / T7962.20-2010.

[0100] 5. Measurement of shortwave transmission spectral characteristics

[0101] The short-wavelength transmission spectral characteristics of optical glass are expressed using colorimetry (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%. 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 Value of Optical Glass" JOGIS02.

[0102] 6. The acid resistance (R) of the obtained optical glass was tested according to the test method of GB / T7962.14-2010. A (Surface method) is used for measurement.

[0103] 7. The moisture resistance stability (R) of the obtained optical glass was tested according to the test method of GB / T7962.15-2010. C (Surface method) is used for measurement.

[0104] 8. Alkali resistance R OH (S) (Surface Method) Measurement

[0105] 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:

[0106] Table 1: Alkali Resistance Grades of Optical Glass

[0107]

[0108] 9. Measurement of Washability Resistance RP(S) (Surface Method)

[0109] 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:

[0110] Table 2: Washability rating of optical glass

[0111]

[0112] 10. Bending strength σ b Measurement of (MPa)

[0113] The fracture load of a finely annealed and polished specimen is tested using the "three-point bending test," and the curvature is calculated using the following formula.

[0114]

[0115] Where: P—fracture load, N;

[0116] L—span distance, mm;

[0117] w—width, mm;

[0118] t — thickness, mm.

[0119] The refractive index n of the optical glass obtained in Examples 1-40 was tested. d Abbe number υ d The relative refractive index temperature coefficient dn / dt relative(10) for the d-line at 40–60℃ -6 / ℃), bending strength σ b (MPa), glass transition temperature T g Density ρ, Liquidus temperature L T , λ 80 λ5, acid resistance (R A Moisture resistance stability (R) C ), alkali resistance R (OH)S, washability RP(S), etc., are listed in Tables 3 to 8, and the measured data of Comparative Examples 1-2 are listed in Table 8.

[0120] Table 3; Glass composition and performance parameters of Examples 1-7

[0121]

[0122] Table 4: Glass composition and performance parameters of Examples 8-14

[0123]

[0124] Table 5: Glass composition and performance parameters of Examples 15-21

[0125]

[0126] Table 6: Glass composition and performance parameters of Examples 22-28

[0127]

[0128] Table 7: Glass composition and performance parameters of Examples 29-35

[0129]

[0130] Table 8: Glass composition and performance parameters of Examples 36-40 and Comparative Examples 1-2

[0131]

[0132] As can be seen from Tables 3 to 8, the optical glass of Examples 1-40 of the present invention has a refractive index n. d Above 1.78, the Abbe number υ d The relative refractive index temperature coefficient dn / dt for the d-line is 8.0 × 10⁻⁶ for the 40–60 °C range of 35–45 °C. -6 Above / ℃, flexural strength above 90MPa, excellent resistance to devitrification, liquidus temperature L T Temperature resistance is below 1000℃, transition temperature is below 605℃, and moisture resistance R C Class 1, acid resistance R A Class 1, alkali resistant R (OH) S is grade 1, washability RP(S) is grade 1, and density is 4.80 g / cm³. 3 Below, λ 80 The wavelength is below 398nm, and λ5 is below 338nm.

[0133] It can be seen that the optical glass obtained in Examples 1-40 of this invention has a large positive refractive index temperature coefficient. When used in combination with optical glass having a negative refractive index temperature coefficient, it can effectively correct temperature drift caused by rapid temperature changes or high-temperature environments, fix the focal point, and maintain clear imaging. It also has high bending strength, making it suitable for harsh environments and ensuring safety and reliability. Furthermore, it exhibits good chemical stability and transmittance, a low transition temperature suitable for precision molding, low density, good devitrification resistance, low production cost, and is suitable for mass production. It also has good bubble and striation characteristics, resulting in excellent internal product quality. Therefore, it is a glass material with outstanding performance and has a wide range of applications in optical design.

[0134] As can be seen from Table 8, Comparative Examples 1-2 do not fully meet all the technical features defined in this application. Therefore, they cannot simultaneously obtain a large positive refractive index temperature coefficient and flexural strength, and a low transition temperature T. g It has good liquid phase temperature and excellent chemical stability.

[0135] 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.

[0136] 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 by comprising: The optical glass contains the following components in mol%: B2O3: 5.0% to 19.9%; SiO2: 5.0% to 28.0%; La2O3: 0.05% to 11.5%; Gd2O3: 0% to 10.0%; Y2O3: 3.6% to 15.0%; ZnO: 30.5% to 60.0%; The ratio Y2O3 / B2O3 of the content of Y2O3 to the content of B2O3 is not less than 0.236 in mol%; The ratio Y2O3 / (La2O3+Gd2O3+Y2O3) of the content of Y2O3 to the sum of the contents of La2O3, Gd2O5 and Y2O3 is not less than 0.41 in mol%; The refractive index n of the optical glass d An Abbe number of υ is above 1.

78. d 35-45; The optical glass has a relative refractive index temperature coefficient dn / dt of 8.0 x 10 -6 / °C or more at 40 to 60°C.

2. The optical glass according to claim 1, characterized by The optical glass contains the following components in mol%: B2O3: 6.0% to 19.5%; SiO2: 6.0% to 25.0%; La2O3: 0.5% to 11.0%; Gd2O3: 0 to 8%; Y2O3: 4.0% to 14.0%; ZnO: 30.5% to 58.0%.

3. The optical glass according to claim 1 or 2, characterized by The optical glass further contains the following components in mol%: ZrO2: 0% to 6.0%; and / or, Nb2O5: 0% to 3.0%; and / or, TiO2: 0% to 3.0%; and / or, R2O: 0% to 2%; and / or, WO3: 0% to 5.0%; and / or, Al2O3: 0% to 5.0%; and / or, SnO2: 0% to 1.0%; and / or, Sb2O3: 0% to 1.0%; wherein, The R2O is one or a combination of two or more of Li2O, Na2O, K2O.

4. The optical glass according to claim 1 or 2, characterized by The ratio Y2O3 / B2O3 of the content of Y2O3 to the content of B2O3 is not less than 0.30 in mol%; and / or The ratio Y2O3 / (La2O3+Gd2O3+Y2O3) of the content of Y2O3 to the sum of the contents of La2O3, Gd2O5 and Y2O3 is not less than 0.45 in mol%.

5. The optical glass according to claim 1 or 2, characterized by, The ratio ZnO / La2O3 of the content of ZnO to the content of La2O3 is not less than 5.2 in mol%; and / or, The ratio ZnO / B2O3 of the content of ZnO to the content of B2O3 is not less than 2.0 in mol%; and / or, The ratio B2O3 / SiO2 of the content of B2O3 to the content of SiO2 is 0.2 to 3.0 in mol%.

6. The optical glass according to claim 5, characterized by The ratio ZnO / La2O3 of the content of ZnO to the content of La2O3 is not less than 5.3 in mol%; and / or, The ratio ZnO / B2O3 of the content of ZnO to the content of B2O3 is not less than 2.3 in mol%; and / or, The ratio B2O3 / SiO2 of the content of B2O3 to the content of SiO2 is 0.25 to 2.8 in mol%.

7. The optical glass according to claim 3, characterized by The ratio (Nb2O5+TiO2+ZrO2+WO3) / (SiO2+B2O3) of the sum of the contents of Nb2O5, TiO2, ZrO2 and WO3 to the sum of the contents of SiO2 and B2O3 is 0.12 to 1.0 in mol%.

8. The optical glass according to claim 7, characterized by The ratio (Nb2O5+TiO2+ZrO2+WO3) / (SiO2+B2O3) of the sum of the contents of Nb2O5, TiO2, ZrO2 and WO3 to the sum of the contents of SiO2 and B2O3 is 0.14 to 0.9 in terms of mol%.

9. The optical glass according to claim 1 or 2, characterized by, The optical glass has a relative refractive index temperature coefficient dn / dt of 8.5 x 10 -6 / ℃ or more at 40-60℃; and / or, The optical glass has a bending strength of 90 MPa or more.

10. The optical glass according to claim 9, characterized by The optical glass has a bending strength of 100 MPa or more.

11. The optical glass according to claim 1 or 2, characterized by, The moisture resistance stability R of the optical glass C was 1; the acid resistance R A was 1; the base resistance R (OH) S was 1; the washing resistance RP(S) was 1; and / or, λ: wavelength at which the transmittance of optical glass having a thickness of 10 mm is 80% 80 λ5: wavelength at which the transmittance of optical glass having a thickness of 10 mm is 5% 12. The optical glass according to claim 11, characterized by λ: wavelength at which the transmittance of optical glass having a thickness of 10 mm is 80% 80 395 nm or less; and λ5: wavelength at which the transmittance of optical glass having a thickness of 10 mm is 5% is 335 nm or less.

13. The optical glass according to claim 1 or 2, characterized by, The optical glass has at least one of the following characteristics: The optical glass has a transition temperature T g of 605°C or less. The optical glass has a liquidus temperature L of 1000°C or less. T 1000°C or less. The optical glass has a density of 4.80 g / cm 3 The following.

14. The optical glass according to claim 13, characterized by The optical glass has at least one of the following characteristics: The optical glass has a transition temperature T g of 600°C or less; The optical glass has a liquidus temperature L of 990°C or less. T 990°C or less. The optical glass has a density of 4.75 g / cm 3 The following.

15. A method of producing an optical glass according to any one of claims 1 to 14, characterized by, The method includes a step of mixing the components of the optical glass.

16. An optical element comprising the optical glass according to any one of claims 1 to 14.

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