Optical glass, glass preform, optical element and optical instrument

Abstract

The invention provides optical glass, which comprises the following components in percentage by weight: 1 to 10 percent of SiO2; 18 to 31 percent of B2O3; 20 to 35 percent of La2O3; 19% to 32% of ZnO; 1 to 14 percent of Gd2O3 and Y2O3; and 0.5 to 12 percent of Nb2O5 + WO3. Through reasonable component design, the optical glass obtained by the invention has expected refractive index and Abbe number, and also has relatively low transformation temperature.

Description

Technical Field

[0001] This invention relates to an optical glass, and more particularly to an optical glass with a low transition temperature, as well as glass preforms, optical elements and optical instruments made therefrom. Background Technology

[0002] In recent years, with the advancement of technology and the continuous upgrading of optoelectronic information products, the demand for optical glass has gradually increased, while higher requirements have been placed on its performance. For the same radius of curvature, glass with a higher refractive index yields a larger imaging field of view. With the trend towards miniaturization of optical devices, the demand for high-refractive-index glass is becoming increasingly apparent. Optical glass with a refractive index of 1.71–1.79 and an Abbe number of 42–49, due to its high refractive index, is easier to miniaturize, achieve ultra-thinness, and wide-angle, making it suitable for a wide range of applications.

[0003] Currently, the mainstream manufacturing method for optical components is precision molding (including direct molding and secondary molding). Lenses manufactured using precision molding technology typically do not require grinding and polishing, thus reducing raw material consumption, labor and material costs, and environmental pollution. This technology allows for the low-cost, mass production of aspherical components. Precision molding involves molding a glass preform into a predetermined shape using a high-precision mold under specific temperature and pressure conditions, resulting in a glass product with the final shape and optical functions. Various optical glass products, such as spherical lenses, aspherical lenses, prisms, and diffraction gratings, can be manufactured using precision molding technology.

[0004] In precision molding, to replicate a high-precision mold surface onto the finished glass product, the glass preform needs to be molded under pressure at high temperatures (typically above the glass transition temperature of 20–60°C). Under these conditions, even within a protective gas environment, the mold surface is easily oxidized and corroded. To extend the mold's lifespan and suppress damage from the high-temperature environment, the molding temperature must be reduced. Therefore, the transition temperature of the glass material used for molding needs to be as low as possible. Patent document CN101857358A discloses a high-refractive-index optical glass with a refractive index of 1.69–1.82 and an Abbe number of 33–46, but its high transition temperature is detrimental to extending the mold's lifespan. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an optical glass with a low transition temperature.

[0006] The technical solution adopted by this invention to solve the technical problem is:

[0007] Optical glass, the composition of which is expressed as a weight percentage, contains: SiO2: 1-10%; B2O3: 18-31%; La2O3: 20-35%; ZnO: 19-32%; Gd2O3+Y2O3: 1-14%; Nb2O5+WO3: 0.5-12%.

[0008] Furthermore, the optical glass, whose composition is expressed as a weight percentage, also contains: ZrO2: 0-10%; and / or Li2O: 0-8%; and / or Na2O: 0-6%; and / or K2O: 0-6%; and / or RO: 0-4%; and / or TiO2: 0-4%; and / or Ta2O5: 0-4%; and / or Al2O3: 0-4%; and / or Yb2O3: 0-10%; and / or F: 0-3%; and / or clarifying agent: 0-1%, wherein the RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0009] Optical glass, the composition of which is expressed as a weight percentage, is composed of SiO2: 1-10%; B2O3: 18-31%; La2O3: 20-35%; ZrO2: 0-10%; ZnO: 19-32%; Gd2O3+Y2O3: 1-14%; Nb2O5+WO3: 0.5-12%; Li2O: 0-8%; Na2O: 0-6%; K2O: 0-6%; RO: 0-4%; TiO2: 0-4%; Ta2O5: 0-4%; Al2O3: 0-4%; Yb2O3: 0-10%; F: 0-3%; and a clarifying agent: 0-1%. The RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0010] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: ZnO / La2O3 is 0.6 to 1.5, preferably 0.7 to 1.4, more preferably 0.8 to 1.3, and even more preferably 0.8 to 1.2.

[0011] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: (Gd2O3+Y2O3) / ZnO is 0.05-0.6, preferably (Gd2O3+Y2O3) / ZnO is 0.1-0.5, more preferably (Gd2O3+Y2O3) / ZnO is 0.15-0.45, and even more preferably (Gd2O3+Y2O3) / ZnO is 0.2-0.4.

[0012] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein:

[0013] The ratio of (Nb2O5+WO3) / SiO2 is 0.1 to 5.0, preferably 0.3 to 3.0, more preferably 0.5 to 2.5, and even more preferably 0.7 to 1.5.

[0014] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: SiO2 / ZnO is 0.05 to 0.45, preferably SiO2 / ZnO is 0.1 to 0.4, and more preferably SiO2 / ZnO is 0.15 to 0.35.

[0015] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: Nb2O5 / Y2O3 is 0.1 to 5.0, preferably 0.2 to 3.0, more preferably 0.3 to 2.5, and even more preferably 0.5 to 1.5.

[0016] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein:

[0017] The ratio of (WO3+Gd2O3+Ta2O5) / ZnO is 1.0 or less, preferably 0.8 or less, more preferably 0.05 to 0.6, and even more preferably 0.1 to 0.45.

[0018] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: Gd2O3 / WO3 is 6.5 or less, preferably 0.1 to 5.0, more preferably 0.5 to 4.0, and even more preferably 1.0 to 3.5.

[0019] Furthermore, the optical glass comprises, by weight percentage, (Nb2O5+WO3) / ZnO of 0.05 to 0.5, preferably (Nb2O5+WO3) / ZnO of 0.08 to 0.4, and more preferably (Nb2O5+WO3) / ZnO of 0.1 to 0.3.

[0020] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.6 to 2.0, preferably (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.7 to 1.8, more preferably (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.8 to 1.5, and even more preferably (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.8 to 1.3.

[0021] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein:

[0022] The ratio of (B2O3+WO3) / SiO2 is 2.5 to 15.0, preferably 3.0 to 10.0, more preferably 3.5 to 8.0, and even more preferably 4.0 to 6.0.

[0023] Furthermore, the optical glass comprises, by weight percentage: SiO2: 2-8%, preferably SiO2: 3-7%; and / or B2O3: 20-29%, preferably B2O3: 22-27%; and / or La2O3: 22-33%, preferably La2O3: 24-31%; and / or ZrO2: 1-8%, preferably ZrO2: 1.5-5.5%; and / or ZnO: 20-28%, preferably ZnO 22-27%; and / or Gd₂O₃+Y₂O₃: 2-12%, preferably Gd₂O₃+Y₂O₃: 2.5-10%; and / or Nb₂O₅+WO₃: 1-10%, preferably Nb₂O₅+WO₃: 2-8%; and / or Li₂O: 0.5-7%, preferably Li₂O: 1-5%; and / or Na₂O: 0-5%, preferably Na₂O: 0-3%, more preferably Na₂O-free; and / or K₂O: 0-5% The preferred components are K2O: 0-3%, more preferably K2O-free; and / or RO: 0-3%, preferably RO: 0-1%, more preferably RO-free; and / or TiO2: 0-3%, preferably TiO2: 0-2%, more preferably TiO2-free; and / or Ta2O5: 0-3%, preferably Ta2O5: 0-1%, more preferably Ta2O5-free; and / or Al2O3: 0-3%, preferably Al2O3: 0-1%, more preferably Al2O3-free; and / or Yb2O3: 0-5%, preferably Yb2O3: 0-2%, more preferably Yb2O3-free; and / or F: 0-2%, preferably F: 0-1%, more preferably F-free; and / or clarifying agent: 0-0.5%, preferably 0-0.2%, wherein the RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

[0024] Furthermore, the optical glass comprises, by weight percentage: Gd₂O₃: 0–10%, preferably 0–8%, more preferably 2–7%; and / or Y₂O₃: 0–10%, preferably 0.5–7%, more preferably 1–5%; and / or Nb₂O₅: 0–10%, preferably 0.5–8%, more preferably 1–6%; and / or WO₃: 0–8%, preferably 0.5–6%, more preferably 1–3.8%.

[0025] Furthermore, the refractive index n of the optical glass... d The Abbe number v is 1.71–1.79, preferably 1.72–1.78, more preferably 1.73–1.77, and even more preferably 1.74–1.765. dThe value is 42 to 49, preferably 43 to 48, more preferably 44 to 47, and even more preferably 44.5 to 46.5.

[0026] Furthermore, the λ of the optical glass 80 For wavelengths below 400nm, λ is preferred. 80 For wavelengths below 390nm, λ is preferred. 80 The wavelength is 380 nm or less; and / or λ5 is 350 nm or less, preferably 340 nm or less, more preferably 330 nm or less; and / or water resistance stability D W It is classified as Class 2 or more, preferably Class 1; and / or the upper limit temperature for crystallization is below 1080°C, preferably below 1050°C, more preferably below 1000°C, and even more preferably below 980°C; and / or the Young's modulus E is 10000 × 10⁻⁶. 7 Pa or higher, preferably 10500×10 Pa 7 / Pa~13000×10 7 / Pa, more preferably 11000×10 7 / Pa~12000×10 7 / Pa; and / or coefficient of thermal expansion α -30 / 70℃ 80×10 -7 / K or less, preferably 75×10 -7 / K or less, preferably 70×10 -7 Below / K, 65×10 is further preferred. -7 / K or below; and / or density ρ is 4.50 g / cm³ 3 The preferred value is 4.40 g / cm³. 3 The preferred value is 4.30 g / cm³. 3 The following is a further preferred value: 4.20 g / cm³ 3 The following; and / or wear degree F A The temperature is 90–130°C, preferably 95–125°C, more preferably 100–120°C; and / or the transition temperature T g Temperature is below 560°C, preferably below 550°C, more preferably below 545°C, and even more preferably below 540°C; and / or Knoop hardness H K 600×10 7 Pa or higher, preferably 610 × 10 Pa 7 Pa or higher, more preferably 620 × 10 Pa 7 Pa or above.

[0027] The glass preform is made of the aforementioned optical glass.

[0028] The optical element is made of the optical glass described above, or of the glass preform described above.

[0029] An optical instrument containing the aforementioned optical glass and / or containing the aforementioned optical elements.

[0030] The beneficial effects of this invention are: through reasonable component design, the optical glass obtained by this invention has both the desired refractive index and Abbe number, as well as a low transition temperature. Detailed Implementation

[0031] The embodiments of the optical glass of the present invention will now be described in detail. However, the present invention is not limited to the embodiments described below, and appropriate modifications can be made to implement it within the scope of the present invention's objectives. Furthermore, while there are instances of appropriate omissions in the repeated descriptions, this does not limit the scope of the invention. In the following text, the optical glass of the present invention will sometimes be simply referred to as glass.

[0032] Optical Glass

[0033] The composition range of each component in the optical glass of the present invention will be described below. In this invention, unless otherwise specified, the content of each component, the total content, and the total content are all expressed as weight percentages (wt%), that is, the weight percentage of the content of each component, the total content, and the total content relative to the total amount of glass material converted into oxide composition. Here, "converted into oxide composition" means that when the oxides, complex salts, and hydroxides used as raw materials for the optical glass of the present invention decompose and transform into oxides upon melting, the total amount of such oxides is taken as 100%.

[0034] Unless otherwise specified in the specific context, the numerical ranges listed herein include upper and lower limits. "Above" and "below" include endpoint values ​​and all integers and fractions within the range, not limited to the specific values ​​listed when the range is defined. The term "and / or" as used herein is inclusive; for example, "A and / or B" means either only A, or only B, or both A and B.

[0035] <Essential and Optional Components>

[0036] B2O3 is a network-forming component of glass, playing a role in maintaining glass stability and improving its melting performance. However, excessively high B2O3 content leads to decreased chemical stability and reduced viscosity, increasing the difficulty of glass forming; conversely, low B2O3 content results in poor vitrification properties and resistance to crystallization, reducing production performance. Therefore, the B2O3 content is 18–31%, preferably 20–29%, and more preferably 22–27%.

[0037] SiO2 can increase the viscosity of molten glass, reduce glass coloration, improve the thermal stability of glass, and enhance devitrification resistance. However, if its content is too high, the difficulty of melting the glass increases, and the transition temperature rises. Therefore, the SiO2 content is 1–10%, preferably 2–8%, and more preferably 3–7%.

[0038] La2O3 is an effective component for improving the refractive index of glass, and it has a significant effect on improving the chemical stability and devitrification resistance of glass. If its content is less than 20%, it is difficult to achieve the required optical constant; if the content is higher than 35%, the glass's devitrification tendency increases and its thermal stability deteriorates. Therefore, the content of La2O3 is 20-35%, preferably 22-33%, and more preferably 24-31%.

[0039] Gd₂O₃ is a high-refractive-index, low-dispersion component that can reduce the relative partial dispersion of glass and improve its chemical stability. However, if its content is too high, the glass's devitrification resistance will deteriorate and the transition temperature will increase. Therefore, in this invention, the content of Gd₂O₃ is 0–10%, preferably 0–8%, and more preferably 2–7%.

[0040] Y₂O₃ can improve the refractive index and devitrification resistance of glass, and adjust the Young's modulus of glass. However, if its content exceeds 10%, the chemical stability and weather resistance of the glass deteriorate. Therefore, in this invention, the Y₂O₃ content is 0–10%, preferably 0.5–7%, and more preferably 1–5%.

[0041] In some embodiments, controlling the total content of Gd₂O₃ and Y₂O₃ (Gd₂O₃+Y₂O₃) within the range of 1-14% allows the optical glass to more easily achieve the desired refractive index and Abbe number while improving its chemical stability and preventing a deterioration in its anti-crystallization properties. Therefore, a content of 1-14% Gd₂O₃+Y₂O₃ is preferred, more preferably 2-12%, and even more preferably 2.5-10%.

[0042] Yb₂O₃ is a component that imparts high refractive index and low dispersion to glass. However, if its content exceeds 10%, the glass's resistance to crystallization decreases. Therefore, the content of Yb₂O₃ is 0–10%, preferably 0–5%, and more preferably 0–2%. In some embodiments, it is even more preferable that Yb₂O₃ is not present.

[0043] ZrO2 can improve the refractive index and devitrification resistance of glass, as well as its chemical stability and mechanical properties. However, if its content is too high, the melting difficulty of the glass increases, which can easily lead to inclusions inside the glass and a decrease in light transmittance. Therefore, the ZrO2 content is 0-10%, preferably 1-8%, and more preferably 1.5-5.5%.

[0044] Nb₂O₅ is a high-refractive-index and high-dispersion component that can improve the devitrification resistance of glass and reduce its coefficient of thermal expansion. However, if the Nb₂O₅ content exceeds 10%, the weather resistance and light transmittance of the glass decrease, and the glass transition temperature increases. Therefore, the Nb₂O₅ content in this invention is 0–10%, preferably 0.5–8%, and more preferably 1–6%.

[0045] In some embodiments, controlling the ratio of Nb₂O₅ content to Y₂O₃ content (Nb₂O₅ / Y₂O₃) within the range of 0.1 to 5.0 can improve the glass's resistance to crystallization and its hardness. Therefore, a Nb₂O₅ / Y₂O₃ ratio of 0.1 to 5.0 is preferred, and a ratio of 0.2 to 3.0 is more preferred. Furthermore, controlling the Nb₂O₅ / Y₂O₃ ratio within the range of 0.3 to 2.5 can further reduce the glass's coefficient of thermal expansion and optimize its abrasion resistance. Therefore, a Nb₂O₅ / Y₂O₃ ratio of 0.3 to 2.5 is even more preferred, and a ratio of 0.5 to 1.5 is still more preferred.

[0046] WO3 can improve the refractive index and dispersion of glass. However, if its content is too high, the light transmittance of the glass will decrease, and the resistance to crystallization during secondary molding will deteriorate. Therefore, the WO3 content in this invention is 0-8%, preferably 0.5-6%, and more preferably 1-3.8%.

[0047] In some embodiments, controlling the total content of Nb₂O₅ and WO₃ (Nb₂O₅+WO₃) within the range of 0.5% to 12% allows the optical glass to more easily achieve the desired refractive index and Abbe number while optimizing its abrasion resistance and preventing an increase in tinting density. Therefore, a content of 0.5% to 12% Nb₂O₅+WO₃ is preferred, 1% to 10% is more preferred, and 2% to 8% is even more preferred.

[0048] In some embodiments, by controlling the ratio of the total content of Nb2O5 and WO3 (Nb2O5+WO3) to the content of SiO2 (Nb2O5+WO3) / SiO2 within the range of 0.1 to 5.0, the hardness and chemical stability of the glass can be improved, and the glass transition temperature can be prevented from rising. Therefore, it is preferable that (Nb2O5+WO3) / SiO2 is 0.1 to 5.0, more preferably (Nb2O5+WO3) / SiO2 is 0.3 to 3.0, further preferably (Nb2O5+WO3) / SiO2 is 0.5 to 2.5, and even more preferably (Nb2O5+WO3) / SiO2 is 0.7 to 1.5.

[0049] In some embodiments, by keeping the ratio of Gd2O3 content to WO3 content (Gd2O3 / WO3) below 6.5, the glass transition temperature can be reduced while the glass abrasion resistance can be optimized. Therefore, it is preferable that the Gd2O3 / WO3 ratio is below 6.5, more preferably 0.1 to 5.0, even more preferably 0.5 to 4.0, and even more preferably 1.0 to 3.5.

[0050] In some embodiments, controlling the ratio of the total content of B2O3 and WO3 (B2O3+WO3) to the content of SiO2 (B2O3+WO3) / SiO2 within the range of 2.5 to 15.0 can improve the hardness and chemical stability of the glass and optimize its abrasion resistance. Therefore, it is preferable that (B2O3+WO3) / SiO2 is 2.5 to 15.0, more preferably (B2O3+WO3) / SiO2 is 3.0 to 10.0, further preferably (B2O3+WO3) / SiO2 is 3.5 to 8.0, and even more preferably (B2O3+WO3) / SiO2 is 4.0 to 6.0.

[0051] ZnO can improve the chemical stability of glass, while also reducing its high-temperature viscosity and transition temperature. This invention achieves these effects by containing more than 19% ZnO. However, if the ZnO content is too high, the glass's resistance to crystallization decreases, and its high-temperature viscosity is low, making molding difficult. Therefore, the ZnO content is 19–32%, preferably 20–28%, and more preferably 22–27%.

[0052] In some embodiments, by controlling the ratio of ZnO content to La2O3 content (ZnO / La2O3) to be in the range of 0.6 to 1.5, the coefficient of thermal expansion of the glass can be reduced, and the wear resistance of the glass can be optimized. Therefore, a ZnO / La2O3 ratio of 0.6 to 1.5 is preferred, a ZnO / La2O3 ratio of 0.7 to 1.4 is more preferred, a ZnO / La2O3 ratio of 0.8 to 1.3 is even more preferred, and a ZnO / La2O3 ratio of 0.8 to 1.2 is even more preferred.

[0053] In some embodiments, controlling the ratio of the total content of Gd2O3 and Y2O3 (Gd2O3+Y2O3) to the content of ZnO (Gd2O3+Y2O3) / ZnO within the range of 0.05 to 0.6 can improve the Young's modulus of the glass and reduce its colorimetric intensity and density. Therefore, it is preferable that (Gd2O3+Y2O3) / ZnO is 0.05 to 0.6, more preferably 0.1 to 0.5, further preferably 0.15 to 0.45, and even more preferably 0.2 to 0.4.

[0054] In some embodiments, maintaining a SiO2 / ZnO ratio (SiO2 / ZnO) in the range of 0.05 to 0.45 can improve the Young's modulus and anti-crystallization properties of the glass, while reducing its coefficient of thermal expansion. Therefore, a SiO2 / ZnO ratio of 0.05 to 0.45 is preferred, more preferably 0.1 to 0.4, and even more preferably 0.15 to 0.35.

[0055] In some embodiments, by controlling the ratio of the total content of Nb2O5 and WO3 (Nb2O5+WO3) to the content of ZnO (Nb2O5+WO3) / ZnO within the range of 0.05 to 0.5, the anti-crystallization properties and Young's modulus of the glass can be improved, and the chemical stability of the glass can be optimized. Therefore, it is preferable that (Nb2O5+WO3) / ZnO is 0.05 to 0.5, more preferably (Nb2O5+WO3) / ZnO is 0.08 to 0.4, and even more preferably (Nb2O5+WO3) / ZnO is 0.1 to 0.3.

[0056] In some embodiments, controlling the ratio of the total content of SiO2, WO3, and La2O3 (SiO2+WO3+La2O3) to the total content of ZnO and Gd2O3 (ZnO+Gd2O3) (SiO2+WO3+La2O3) / (ZnO+Gd2O3) within the range of 0.6 to 2.0 can improve the hardness and chemical stability of the glass and optimize its wear resistance. Therefore, the preferred ratio of (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.6 to 2.0, more preferably (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.7 to 1.8, further preferably (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.8 to 1.5, and even more preferably (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.8 to 1.3.

[0057] Li₂O can lower the glass transition temperature and improve the glass's melting properties, but high Li₂O content is detrimental to the glass's chemical stability, resistance to crystallization, and coefficient of thermal expansion. Therefore, the Li₂O content in this invention is 0–8%, preferably 0.5–7%, and more preferably 1–5%.

[0058] Na₂O can improve the chemical stability of glass and enhance its resistance to crystallization during secondary molding. However, if the Na₂O content is too high, the refractive index of the glass may not meet the design requirements. Therefore, the Na₂O content is 0–6%, preferably 0–5%, and more preferably 0–3%. In some embodiments, it is further preferred that the glass does not contain Na₂O.

[0059] K2O improves the thermal stability and melt properties of glass; however, if its content exceeds 6%, the glass's resistance to devitrification and chemical stability deteriorate. Therefore, the K2O content in this invention is 0–6%, preferably 0–5%, and more preferably 0–3%. In some embodiments, it is further preferred that no K2O is present.

[0060] RO (RO being one or more of MgO, CaO, SrO, and BaO) can improve the meltability of glass and adjust its optical constants. However, if its content exceeds 4%, the glass's devitrification resistance decreases. Therefore, in this invention, the RO content is 0-4%, preferably 0-3%, and more preferably 0-1%. In some embodiments, it is further preferred that the glass does not contain MgO; and / or does not contain CaO; and / or does not contain SrO; and / or does not contain BaO.

[0061] TiO2 improves the refractive index and dispersion of glass, and enhances its resistance to devitrification. However, if its content exceeds 4%, the glass's tendency to crystallize and color increases, and its transition temperature rises. Therefore, in this invention, the TiO2 content is 4% or less, preferably 3% or less, and more preferably 2% or less. In some embodiments, it is further preferred that TiO2 is not present.

[0062] Ta2O5 can improve the refractive index and devitrification resistance of glass, but if its content is too high, the thermal stability of the glass will decrease, the density will increase, and it will be detrimental to the cost control of glass raw materials. Therefore, the content of Ta2O5 in this invention is 0-4%, preferably 0-3%, and more preferably 0-1%. In some embodiments, it is even more preferable that Ta2O5 is not present.

[0063] In some embodiments, by controlling the total content of WO3, Gd2O3, and Ta2O5, the ratio of WO3+Gd2O3+Ta2O5 to ZnO (WO3+Gd2O3+Ta2O5) / ZnO to be below 1.0, the colorimetric intensity of the glass can be reduced while preventing a decrease in Young's modulus. Therefore, it is preferable that (WO3+Gd2O3+Ta2O5) / ZnO is below 1.0, more preferably below 0.8. Furthermore, keeping (WO3+Gd2O3+Ta2O5) / ZnO in the range of 0.05 to 0.6 can further improve the hardness of the glass. Therefore, it is even more preferable that (WO3+Gd2O3+Ta2O5) / ZnO is 0.05 to 0.6, and even more preferably 0.1 to 0.45.

[0064] Al2O3 reduces the coefficient of thermal expansion of glass and improves its thermal stability. However, excessive Al2O3 content leads to an increase in the glass transition temperature and the high-temperature viscosity of the glass, making it difficult to eliminate bubbles. Therefore, the Al2O3 content is 0–4%, preferably 0–3%, and more preferably 0–1%. In some embodiments, it is even more preferable that the glass does not contain Al2O3.

[0065] In this invention, one or more components selected from Sb₂O₃, SnO₂, SnO, and CeO₂ are used as clarifying agents, which can improve the clarification effect and increase the bubble content of the glass. Preferably, the content of the clarifying agent is 0-0.5%, and more preferably, it is 0-0.2%. Because the composition and content of the optical glass of this invention are reasonably designed, its bubble content is excellent. Therefore, in some embodiments, it is further preferred that the glass does not contain a clarifying agent.

[0066] F can be used to adjust the refractive index of glass and reduce the temperature coefficient of refractive index. However, during the production of optical glass, F volatilization causes environmental pollution. Furthermore, in the forming temperature range, its volatilization from the glass surface creates heterogeneous components, reducing glass quality and the consistency of optical constants. Therefore, the F content is 0–3%, preferably 0–2%, and more preferably 0–1%. In some embodiments, it is further preferred that F is not present.

[0067] <Components that should not be present>

[0068] In the glass of this invention, even if oxides of transition metals such as V, Cr, Mn, Fe, Co, Ni, Cu, Ag, and Mo are contained in small amounts, either alone or in combination, the glass will be colored and absorb at specific wavelengths in the visible light region, thereby weakening the property of this invention to improve visible light transmittance. Therefore, it is preferable that the glass does not contain these oxides, especially for optical glass where transmittance in the visible light region is required.

[0069] Oxides of Th, Cd, Tl, Os, Be, and Se have been increasingly subject to controlled use in recent years due to their status as hazardous chemicals. Environmental protection measures are essential not only in glass manufacturing but also in processing and post-product disposal. Therefore, given the importance of environmental impact, it is preferable to avoid the presence of these substances, except where their contamination is unavoidable. This results in optical glass that is virtually free of pollutants. Consequently, the optical glass of this invention can be manufactured, processed, and disposed of even without specific environmental countermeasures. Furthermore, to achieve environmental friendliness, the optical glass of this invention preferably does not contain As₂O₃ and PbO.

[0070] The terms "not containing" and "0%" as used herein mean that the compound, molecule, or element was not intentionally added to the optical glass of this invention as a raw material; however, as raw materials and / or equipment for producing optical glass, there may be certain impurities or components that are not intentionally added, which may be present in small or trace amounts in the final optical glass, and such cases are also within the scope of protection of this patent.

[0071] The performance of the optical glass of the present invention will be described below:

[0072] <Refractive Index and Abbe Number>

[0073] The refractive index (n) of optical glass d ) and Abbe number (ν d Test according to the method specified in GB / T 7962.1—2010.

[0074] In some embodiments, the refractive index (n) of the optical glass of the present invention d The upper limit of ) is 1.79, the preferred upper limit is 1.78, the more preferred upper limit is 1.77, and the even more preferred upper limit is 1.765.

[0075] In some embodiments, the refractive index (n) of the optical glass of the present invention d The lower limit is 1.71, the preferred lower limit is 1.72, the more preferred lower limit is 1.73, and the even more preferred lower limit is 1.74.

[0076] In some embodiments, the Abbe number (ν) of the optical glass of the present invention dThe upper limit of ) is 49, the preferred upper limit is 48, the more preferred upper limit is 47, and the even more preferred upper limit is 46.5.

[0077] In some embodiments, the Abbe number (ν) of the optical glass of the present invention d The lower limit is 42, the preferred lower limit is 43, the more preferred lower limit is 44, and the even more preferred lower limit is 44.5.

[0078] <shading>

[0079] The short-wavelength transmission spectral characteristics of the optical glass of this invention are expressed using chromaticity (λ). 80 And λ5) represent. λ 80 This refers to the wavelength corresponding to a glass transmittance of 80%. λ 80 The measurement was performed using a glass with a thickness of 10 ± 0.1 mm and two optically polished, parallel planes. The spectral transmittance was measured in the wavelength range from 280 nm to 700 nm, and wavelengths exhibiting 80% transmittance were recorded. Spectroscopic transmittance, or transmittance, is the value of the light incident perpendicularly to the aforementioned surface of the glass with an intensity I... in Light passes through the glass and exits from a plane with an intensity of I. out In the case of light, through I out / I in The value represents the transmittance, which also includes the surface reflection loss on the aforementioned surfaces of the glass. The higher the refractive index of the glass, the greater the surface reflection loss. Therefore, λ 80 A low value means that the glass itself has very little coloration and high light transmittance.

[0080] The same applies to λ5.

[0081] In some embodiments, the λ of the optical glass of the present invention 80 For wavelengths below 400nm, λ is preferred. 80 For wavelengths below 390nm, λ is preferred. 80 It is below 380nm.

[0082] In some embodiments, the λ5 of the optical glass of the present invention is 350 nm or less, preferably 340 nm or less, and more preferably 330 nm or less.

[0083] <Stability under water resistance>

[0084] Water resistance stability of optical glass (D) W (Powder method) Tested according to the method specified in GB / T 17129.

[0085] In some embodiments, the water resistance stability (D) of the optical glass of the present invention is... W There are two or more categories, with category 1 being preferred.

[0086] <Upper limit temperature for crystallization>

[0087] The anti-crystallization performance of optical glass was determined by the gradient furnace method. The glass was made into a sample of 180×10×10mm, the side was polished, and it was placed in a furnace with a temperature gradient (10℃ / cm) and a maximum temperature of 1200℃ for 4 hours. After being taken out and naturally cooled to room temperature, the crystallization of the glass was observed under a microscope. The highest temperature at which crystals appeared in the glass was the upper limit temperature for crystallization of the glass.

[0088] In some embodiments, the upper limit temperature for crystallization of the optical glass of the present invention is below 1080°C, preferably below 1050°C, more preferably below 1000°C, and even more preferably below 980°C.

[0089] Young's Modulus

[0090] The Young's modulus (E) of optical glass is obtained by ultrasonic testing of its longitudinal and transverse wave velocities, and then calculated using the following formula.

[0091]

[0092] G = V S 2 ρ

[0093] In the formula: E is Young's modulus, Pa;

[0094] G is the shear modulus, Pa;

[0095] V T The transverse wave velocity is in m / s;

[0096] V S The longitudinal wave velocity is given in m / s.

[0097] ρ is the density of glass, in g / cm³ 3 .

[0098] In some embodiments, the Young's modulus (E) of the optical glass of the present invention is 10000 × 10⁻⁶. 7 Pa or higher, preferably 10500×10 Pa 7 / Pa~13000×10 7 / Pa, more preferably 11000×10 7 / Pa~12000×10 7 / Pa.

[0099] <Coefficient of thermal expansion>

[0100] The coefficient of thermal expansion of optical glass (α) -30 / 70℃ The results were tested according to the method specified in GB / T7962.16-2010 for temperatures ranging from -30°C to 70°C.

[0101] In some embodiments, the coefficient of thermal expansion (α) of the optical glass of the present invention is... -30 / 70℃ ) is 80×10 -7 / K or less, preferably 75×10 -7 / K or less, preferably 70×10 -7 Below / K, 65×10 is further preferred. -7 / K or below.

[0102] <Density>

[0103] The density (ρ) of optical glass is tested according to the method specified in GB / T7962.20-2010.

[0104] In some embodiments, the density (ρ) of the optical glass of the present invention is 4.50 g / cm³. 3 The preferred value is 4.40 g / cm³. 3 The preferred value is 4.30 g / cm³. 3 The following is a further preferred value: 4.20 g / cm³ 3 the following.

[0105] <wear level>

[0106] Abrasion resistance (F) of optical glass A The wear amount (volume) refers to the ratio of the wear amount of the test specimen to the wear amount (volume) of the standard specimen (H-K9 glass) under exactly the same conditions, multiplied by 100. The formula is as follows:

[0107] F A =V / V0×100=(W / ρ) / (W0 / ρ0)×100

[0108] Where: V—volume wear of the tested sample;

[0109] V0—Standard sample volume wear amount;

[0110] W—Mass wear of the tested sample;

[0111] W0—Standard sample mass wear amount;

[0112] ρ—Density of the sample being measured;

[0113] ρ0 — density of the standard sample.

[0114] In some embodiments, the abrasion degree (F) of the optical glass of the present invention A The upper limit of ) is 130, the preferred upper limit is 125, and the more preferred upper limit is 120.

[0115] In some embodiments, the abrasion degree (F) of the optical glass of the present inventionA The lower limit is 90, the preferred lower limit is 95, and the more preferred lower limit is 100.

[0116] <Transition Temperature>

[0117] Transition temperature of optical glass (T) g Test according to the method specified in GB / T7962.16-2010.

[0118] In some embodiments, the transition temperature (T) of the optical glass of the present invention is... g The temperature is 560°C or below, preferably 550°C or below, more preferably 545°C or below, and even more preferably 540°C or below.

[0119] Knoop Hardness

[0120] Knoop hardness (H) of optical glass K The test was conducted according to the test method specified in GB / T7962.18-2010. In this invention, Knoop hardness is sometimes simply referred to as hardness.

[0121] In some embodiments, the Knoop hardness (H) of the optical glass of the present invention is... K ) is 600×10 7 Pa or higher, preferably 610 × 10 Pa 7 Pa or higher, more preferably 620 × 10 Pa 7 Pa or above.

[0122] [Manufacturing Method]

[0123] The manufacturing method of the optical glass of this invention is as follows: The glass of this invention is produced using conventional raw materials and processes, including but not limited to using oxides, hydroxides, fluorides, and various salts (carbonates, nitrates, sulfates), etc., as raw materials. After being batched according to conventional methods, the batched furnace charge is put into a melting furnace (such as a platinum, gold, or platinum alloy crucible) at 900-1400°C for melting. After clarification and homogenization, a homogeneous molten glass without bubbles and undissolved substances is obtained. This molten glass is then cast in a mold and annealed. Those skilled in the art can appropriately select raw materials, process methods, and process parameters according to actual needs.

[0124] [Glass preforms and optical components]

[0125] Glass preforms can be manufactured from the produced optical glass using methods such as direct drop forming, grinding, or hot pressing. Specifically, glass preforms can be manufactured by directly and precisely drop-forming molten optical glass into precision glass preforms, or by machining such as grinding and polishing, or by hot pressing a preform made from optical glass for compression molding followed by grinding. It should be noted that the methods for preparing glass preforms are not limited to the methods described above.

[0126] As described above, the optical glass of the present invention is useful for various optical components and optical designs. It is particularly preferred to form a preform from the optical glass of the present invention, and to use the preform for hot pressing, precision stamping, etc., to manufacture optical components such as lenses and prisms.

[0127] Both the glass preform and the optical element of the present invention are formed from the optical glass described above. The glass preform of the present invention possesses the excellent properties of optical glass; the optical element of the present invention possesses the excellent properties of optical glass, and can provide various optical elements such as lenses and prisms with high optical value.

[0128] Examples of lenses include concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, plano-concave lenses, and so on, where the lens surface is spherical or aspherical.

[0129] [Optical Instruments]

[0130] The optical elements formed by the optical glass of this invention can be used to manufacture optical instruments such as photographic equipment, video equipment, projection equipment, display equipment, vehicle-mounted equipment, and monitoring equipment.

[0131] Example

[0132] <Example of Optical Glass>

[0133] To further illustrate and explain the technical solution of the present invention, the following non-limiting embodiments are provided.

[0134] In this embodiment, optical glass with the composition shown in Tables 1 to 3 was obtained using the optical glass manufacturing method described above. Furthermore, the properties of each glass were measured using the testing method described in this invention, and the measurement results are shown in Tables 1 to 3.

[0135] Table 1.

[0136]

[0137]

[0138]

[0139] Table 2.

[0140]

[0141]

[0142] Table 3.

[0143]

[0144]

[0145] <Example of Glass Prefabricated Components>

[0146] The glass obtained from optical glass Examples 1 to 24# is used to manufacture preforms of various lenses and prisms, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses, by means of grinding, hot pressing, precision stamping, or other molding methods.

[0147] <Optical Component Examples>

[0148] Annealing these preforms obtained from the above glass preform examples reduces internal deformation of the glass while fine-tuning them so that optical properties such as refractive index reach the desired values.

[0149] Next, the prefabricated parts are ground and polished to produce various lenses and prisms, such as concave meniscus lenses, convex meniscus lenses, biconvex lenses, biconcave lenses, plano-convex lenses, and plano-concave lenses. Anti-reflective coatings can also be applied to the surface of the resulting optical elements.

[0150] <Examples of Optical Instruments>

[0151] The optical elements obtained from the above-described optical element embodiments can be used, through optical design, to form optical components or optical assemblies by using one or more optical elements. They can be used in, for example, imaging devices, sensors, microscopes, medical technology, digital projection, communications, optical communication technology / information transmission, optics / lighting in the automotive field, photolithography, excimer lasers, wafers, computer chips, and integrated circuits and electronic devices including such circuits and chips, or for camera equipment and devices in the automotive field.

Claims

1. Optical glass, characterized in that, Its composition, expressed as a weight percentage, contains: SiO2: 1–10%; B2O3: 18–31%; La2O3: 20–35%; ZnO: 19–32%; Gd2O3+Y2O3: 1–14%; Nb2O5+WO3: 0.5–12%.

2. The optical glass according to claim 1, characterized in that, Its components, expressed as a weight percentage, also contain: ZrO2: 0–10%; and / or Li2O: 0–8%; and / or Na2O: 0–6%; and / or K2O: 0–6%; and / or RO: 0–4%; and / or TiO2: 0–4%; and / or Ta2O5: 0–4%; and / or Al2O3: 0–4%; and / or Yb2O3: 0–10%; and / or F: 0–3%; and / or clarifying agent: 0–1%, wherein the RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

3. Optical glass, characterized in that, Its composition, expressed as a weight percentage, is as follows: SiO2: 1–10%; B2O3: 18–31%; La2O3: 20–35%; ZrO2: 0–10%; ZnO: 19–32%; Gd2O3+Y2O3: 1–14%; Nb2O5+WO3: 0.5–12%; Li2O: 0–8%; Na2O: 0–6%; K2O: 0–6%. RO: 0-4%; TiO2: 0-4%; Ta2O5: 0-4%; Al2O3: 0-4%; Yb2O3: 0-10%; F: 0-3%; clarifying agent: 0-1% composition, wherein RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

4. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: ZnO / La2O3 is 0.6 to 1.5, preferably ZnO / La2O3 is 0.7 to 1.4, more preferably ZnO / La2O3 is 0.8 to 1.3, and even more preferably ZnO / La2O3 is 0.8 to 1.

2.

5. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: (Gd2O3+Y2O3) / ZnO is 0.05-0.6, preferably (Gd2O3+Y2O3) / ZnO is 0.1-0.5, more preferably (Gd2O3+Y2O3) / ZnO is 0.15-0.45, and even more preferably (Gd2O3+Y2O3) / ZnO is 0.2-0.

4.

6. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: (Nb2O5+WO3) / SiO2 is 0.1 to 5.0, preferably (Nb2O5+WO3) / SiO2 is 0.3 to 3.0, more preferably (Nb2O5+WO3) / SiO2 is 0.5 to 2.5, and even more preferably (Nb2O5+WO3) / SiO2 is 0.7 to 1.

5.

7. The optical glass according to any one of claims 1 to 3, characterized in that, Its composition is expressed as a weight percentage, wherein: SiO2 / ZnO is 0.05 to 0.45, preferably SiO2 / ZnO is 0.1 to 0.4, and more preferably SiO2 / ZnO is 0.15 to 0.

35.

8. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: Nb2O5 / Y2O3 is 0.1 to 5.0, preferably 0.2 to 3.0, more preferably 0.3 to 2.5, and even more preferably 0.5 to 1.

5.

9. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: (WO3+Gd2O3+Ta2O5) / ZnO is 1.0 or less, preferably (WO3+Gd2O3+Ta2O5) / ZnO is 0.8 or less, more preferably (WO3+Gd2O3+Ta2O5) / ZnO is 0.05 to 0.6, and even more preferably (WO3+Gd2O3+Ta2O5) / ZnO is 0.1 to 0.

45.

10. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: Gd2O3 / WO3 is 6.5 or less, preferably Gd2O3 / WO3 is 0.1 to 5.0, more preferably Gd2O3 / WO3 is 0.5 to 4.0, and even more preferably Gd2O3 / WO3 is 1.0 to 3.

5.

11. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: (Nb2O5+WO3) / ZnO is 0.05 to 0.5, preferably (Nb2O5+WO3) / ZnO is 0.08 to 0.4, and more preferably (Nb2O5+WO3) / ZnO is 0.1 to 0.

3.

12. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.6 to 2.0, preferably (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.7 to 1.8, more preferably (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.8 to 1.5, and even more preferably (SiO2+WO3+La2O3) / (ZnO+Gd2O3) is 0.8 to 1.

3.

13. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: (B2O3+WO3) / SiO2 is 2.5 to 15.0, preferably (B2O3+WO3) / SiO2 is 3.0 to 10.0, more preferably (B2O3+WO3) / SiO2 is 3.5 to 8.0, and even more preferably (B2O3+WO3) / SiO2 is 4.0 to 6.

0.

14. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: SiO2: 2-8%, preferably SiO2: 3-7%; and / or B2O3: 20-29%, preferably B2O3: 22-27%; and / or La2O3: 22-33%, preferably La2O3: 24-31%; and / or ZrO2: 1-8%, preferably ZrO2: 1.5-5.5%; and / or ZnO: 20-28%, preferably ZnO: 22-27%; and / Or Gd₂O₃+Y₂O₃: 2-12%, preferably Gd₂O₃+Y₂O₃: 2.5-10%; and / or Nb₂O₅+WO₃: 1-10%, preferably Nb₂O₅+WO₃: 2-8%; and / or Li₂O: 0.5-7%, preferably Li₂O: 1-5%; and / or Na₂O: 0-5%, preferably Na₂O: 0-3%, more preferably Na₂O-free; and / or K₂O: 0-5%, preferably K₂O: 0-3%, preferably free of K2O; and / or RO: 0-3%, preferably RO: 0-1%, more preferably free of RO; and / or TiO2: 0-3%, preferably TiO2: 0-2%, more preferably free of TiO2; and / or Ta2O5: 0-3%, preferably Ta2O5: 0-1%, more preferably free of Ta2O5; and / or Al2O3: 0-3%, preferably Al2O3: 0-1%, more preferably free of Al2O3; and / or Yb2O3: 0-5%, preferably Yb2O3: 0-2%, more preferably free of Yb2O3; and / or F: 0-2%, preferably F: 0-1%, more preferably free of F; and / or clarifying agent: 0-0.5%, preferably clarifying agent: 0-0.2%, wherein the RO is one or more of MgO, CaO, SrO, and BaO, and the clarifying agent is one or more of Sb2O3, SnO, SnO2, and CeO2.

15. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: Gd2O3: 0-10%, preferably Gd2O3: 0-8%, more preferably Gd2O3: 2-7%; and / or Y2O3: 0-10%, preferably Y2O3: 0.5-7%, more preferably Y2O3: 1-5%; and / or Nb2O5: 0-10%, preferably Nb2O5: 0.5-8%, more preferably Nb2O5: 1-6%; and / or WO3: 0-8%, preferably WO3: 0.5-6%, more preferably WO3: 1-3.8%.

16. The optical glass according to any one of claims 1 to 3, characterized in that, The refractive index n of the optical glass d The Abbe number v is 1.71–1.79, preferably 1.72–1.78, more preferably 1.73–1.77, and even more preferably 1.74–1.

765. d The value is 42 to 49, preferably 43 to 48, more preferably 44 to 47, and even more preferably 44.5 to 46.

5.

17. The optical glass according to any one of claims 1 to 3, characterized in that, The λ of the optical glass 80 For wavelengths below 400nm, λ is preferred. 80 For wavelengths below 390nm, λ is preferred. 80 The wavelength is 380 nm or less; and / or λ5 is 350 nm or less, preferably 340 nm or less, more preferably 330 nm or less; and / or water resistance stability D W It is classified as Class 2 or more, preferably Class 1; and / or the upper limit temperature for crystallization is below 1080°C, preferably below 1050°C, more preferably below 1000°C, and even more preferably below 980°C; and / or the Young's modulus E is 10000 × 10⁻⁶. 7 Pa or higher, preferably 10500×10 Pa 7 / Pa~13000×10 7 / Pa, more preferably 11000×10 7 / Pa~12000×10 7 / Pa; and / or coefficient of thermal expansion α -30 / 70℃ 80×10 -7 / K or less, preferably 75×10 -7 / K or less, preferably 70×10 -7 Below / K, 65×10 is further preferred. -7 / K or below; and / or density ρ is 4.50 g / cm³ 3 The preferred value is 4.40 g / cm³. 3 The preferred value is 4.30 g / cm³. 3 The following is a further preferred value: 4.20 g / cm³ 3 The following; and / or wear degree F A The temperature is 90–130°C, preferably 95–125°C, more preferably 100–120°C; and / or the transition temperature T g Temperature is below 560°C, preferably below 550°C, more preferably below 545°C, and even more preferably below 540°C; and / or Knoop hardness H K 600×10 7 Pa or higher, preferably 610 × 10 Pa 7 Pa or higher, more preferably 620 × 10 Pa 7 Pa or above.

18. A glass precast component, characterized in that, It is made of the optical glass described in any one of claims 1 to 17.

19. An optical element, characterized in that, It is made of optical glass as described in any one of claims 1 to 17, or of glass preform as described in claim 18.

20. An optical instrument, characterized in that, It contains the optical glass according to any one of claims 1 to 17, and / or contains the optical element according to claim 19.

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