Optical glass

Abstract

The invention provides optical glass, which comprises the following components in percentage by weight: 36 to 49 percent of SiO2; 21 to 37 percent of TiO2; 6 to 20 percent of Na2O; 3%-15% of K2O; baO: greater than 0 but less than or equal to 10%. Through reasonable component design, the optical glass obtained by the invention has lower transformation temperature, and is suitable for manufacturing optical elements by precise mould pressing.

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. 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.

[0003] 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 (usually above the glass transition temperature of 20–60°C). Under these conditions, even in 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. Chinese patent CN102442775A discloses an optical glass with a refractive index of 1.63–1.72 and an Abbe number of 29–40, possessing a transition temperature of 452–525°C. Although its transition temperature is low, it contains 30–60 wt% PbO, which does not meet environmental protection requirements. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide an optical glass with a low transition temperature.

[0005] The technical solution adopted by this invention to solve the technical problem is:

[0006] Optical glass, whose composition is expressed as a weight percentage, contains: SiO2: 36-49%; TiO2: 21-37%; Na2O: 6-20%; K2O: 3-15%; BaO: greater than 0 but less than or equal to 10%.

[0007] Furthermore, the optical glass, in weight percentage, further contains: Li₂O: 0–8%; and / or ZnO: 0–10%; and / or SrO: 0–5%; and / or CaO: 0–5%; and / or MgO: 0–5%; and / or B₂O₃: 0–4%; and / or Ln₂O₃: 0–4%; and / or ZrO₂: 0–5%; and / or Nb₂O₅: 0–4%; and / or WO₃: 0–4%; and / or Al₂O₃: 0–4%; and / or P₂O₅: 0–4%; and / or clarifying agent: 0–1%; and / or F: 0–3%, wherein Ln₂O₃ is one or more of La₂O₃, Gd₂O₃, Y₂O₃, and Yb₂O₃, and the clarifying agent is one or more of Sb₂O₃, SnO₂, SnO, and CeO₂.

[0008] Optical glass, its composition expressed as a weight percentage, consists of: SiO2: 36–49%; TiO2: 21–37%; Na2O: 6–20%; K2O: 3–15%; BaO: greater than 0 but less than or equal to 10%; Li2O: 0–8%; ZnO: 0–10%; SrO: 0–5%; CaO: 0–5%; MgO: 0–5%; B2O3: 0–4%; Ln2O3: Composition: 0-4%; ZrO2: 0-5%; Nb2O5: 0-4%; WO3: 0-4%; Al2O3: 0-4%; P2O5: 0-4%; clarifying agent: 0-1%; F: 0-3%, wherein Ln2O3 is one or more of La2O3, Gd2O3, Y2O3, and Yb2O3, and the clarifying agent is one or more of Sb2O3, SnO2, SnO, and CeO2.

[0009] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein (SiO2+ZrO2) / TiO2 is 1.0 to 2.2, preferably (SiO2+ZrO2) / TiO2 is 1.1 to 2.0, more preferably (SiO2+ZrO2) / TiO2 is 1.2 to 1.8, and even more preferably (SiO2+ZrO2) / TiO2 is 1.2 to 1.6.

[0010] Furthermore, the optical glass, wherein the composition is expressed as a weight percentage, wherein (Nb2O5+WO3) / BaO is 1.0 or less, preferably (Nb2O5+WO3) / BaO is 0.8 or less, more preferably (Nb2O5+WO3) / BaO is 0.5 or less, and even more preferably (Nb2O5+WO3) / BaO is 0.2 or less.

[0011] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: Li2O / BaO is 0.15 to 5.0, preferably Li2O / BaO is 0.2 to 3.0, more preferably Li2O / BaO is 0.3 to 2.0, and even more preferably Li2O / BaO is 0.4 to 1.5.

[0012] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: TiO2 / BaO is 3.0 to 30.0, preferably 4.0 to 15.0, more preferably 5.0 to 10.0, and even more preferably 5.5 to 9.0.

[0013] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: SiO2 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5) is 4.5 to 40.0, preferably SiO2 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5) is 6.0 to 30.0, more preferably SiO2 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5) is 7.0 to 20.0, and even more preferably SiO2 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5) is 8.6 to 12.0.

[0014] Furthermore, the optical glass, wherein the composition is expressed as a weight percentage, wherein (Nb2O5+ZrO2) / Li2O is 1.8 or less, preferably (Nb2O5+ZrO2) / Li2O is 1.5 or less, more preferably (Nb2O5+ZrO2) / Li2O is 1.0 or less, and even more preferably (Nb2O5+ZrO2) / Li2O is 0.5 or less.

[0015] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein:

[0016] The ratio of (Li2O+Na2O+K2O) / TiO2 is 0.4 to 2.0, preferably 0.4 to 1.5, more preferably 0.5 to 1.3, and even more preferably 0.7 to 1.0.

[0017] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: BaO / K2O is 0.95 or less, preferably BaO / K2O is 0.1 to 0.9, more preferably BaO / K2O is 0.2 to 0.8, even more preferably BaO / K2O is 0.3 to 0.7, and even more preferably BaO / K2O is 0.46 to 0.65.

[0018] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: (SiO2+BaO) / Li2O is 5.0 to 39.0, preferably (SiO2+BaO) / Li2O is 8.0 to 35.0, more preferably (SiO2+BaO) / Li2O is 10.0 to 30.0, and even more preferably (SiO2+BaO) / Li2O is 15.0 to 26.0.

[0019] Furthermore, the composition of the optical glass is expressed as a weight percentage, wherein: ZnO / Li2O is 6.0 or less, preferably ZnO / Li2O is 5.0 or less, more preferably ZnO / Li2O is 0.1 to 3.0, even more preferably ZnO / Li2O is 0.1 to 1.5, and even more preferably ZnO / Li2O is 0.2 to 1.0.

[0020] Furthermore, the optical glass comprises, by weight percentage: SiO2: 38-47%, preferably SiO2: 40-45%; and / or TiO2: 25-35%, preferably TiO2: 27-33%; and / or Na2O: 8-18%, preferably Na2O: 10.5-16%; and / or K2O: 5-12%, preferably K2O: 6.5-10%; and / or BaO: 0.5-8%, preferably BaO: 1-4.5%; and / or Li₂O: 0.1–6%, preferably 0.5–4%; and / or ZnO: 0.1–8%, preferably 0.5–6.5%; and / or SrO: 0–3%, preferably 0–2%, more preferably without SrO; and / or CaO: 0–3%, preferably 0–2%, more preferably without CaO; and / or MgO: 0–3%, preferably 0–2%, more preferably without MgO; and / or B₂O₃: 0–3%, preferably B₂O₃. B2O3: 0-2%, preferably free of B2O3; and / or Ln2O3: 0-3%, preferably 0-2%, more preferably free of Ln2O3; and / or ZrO2: 0-3%, preferably 0-2%; and / or Nb2O5: 0-3%, preferably 0-2%, more preferably free of Nb2O5; and / or WO3: 0-3%, preferably 0-2%, more preferably free of WO3; and / or Al2O3: 0-3%. The preferred components are Al2O3: 0-2%; and / or P2O5: 0-3%, preferably P2O5: 0-1%, more preferably without P2O5; and / or clarifying agent: 0-0.5%, preferably 0-0.2%; and / or F: 0-2%, preferably F: 0-1%, more preferably without F, wherein the Ln2O3 is one or more of La2O3, Gd2O3, Y2O3, and Yb2O3, and the clarifying agent is one or more of Sb2O3, SnO2, SnO, and CeO2.

[0021] Furthermore, the refractive index n of the optical glass... d The Abbe number is 1.65–1.72, preferably 1.66–1.71, and more preferably 1.67–1.70; d The value is 27 to 34, preferably 28 to 33, and more preferably 29 to 32.

[0022] Furthermore, the λ of the optical glass 80 For wavelengths below 420nm, λ is preferred. 80 For wavelengths below 415nm, λ is preferred. 80 For wavelengths below 410nm, λ is further preferred. 80The wavelength is 405 nm or less; and / or λ5 is 385 nm or less, preferably 380 nm or less, more preferably 375 nm or less, and even more preferably 370 nm or less; and / or water resistance stability D W It is classified as Class 2 or above, preferably Class 1; and / or acid resistance stability D A It is classified as Class 2 or more, preferably Class 1; and / or the upper limit temperature for crystallization is 980°C or below, preferably 950°C or below, more preferably 920°C or below, and even more preferably 900°C or below; and / or the coefficient of thermal expansion α 100 / 300℃ 150×10 -7 / K or less, preferably 140×10 -7 / K or less, preferably 135×10 -7 / K below; and / or density ρ of 3.20 g / cm³ 3 The preferred value is 3.10 g / cm³. 3 The following is a preferred value: 3.00 g / cm³ 3 The following is a further preferred value: 2.95 g / cm³ 3 The following; and / or transition temperature T g The temperature is below 540°C, preferably below 530°C, more preferably below 520°C, and even more preferably below 515°C; and / or the weather resistance CR is Class 2 or above, preferably Class 1; and / or the bubble density is Grade A or above, preferably Grade A0 or above, more preferably Grade A. 00 Grade; and / or stripe density of grade C or above, preferably grade B or above, more preferably grade A.

[0023] The glass preform is made of the aforementioned optical glass.

[0024] The optical element is made of the optical glass described above, or of the glass preform described above.

[0025] An optical instrument containing the aforementioned optical glass and / or containing the aforementioned optical elements.

[0026] The beneficial effects of this invention are: through reasonable component design, the optical glass obtained by this invention has a lower transition temperature, which is suitable for precision molding of optical components. Detailed Implementation

[0027] 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.

[0028] Optical Glass

[0029] 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%.

[0030] 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.

[0031] <Essential and Optional Components>

[0032] SiO2 is a network-forming component of glass, which can increase the viscosity of molten glass, improve its thermal stability, enhance its resistance to devitrification, and reduce the erosion of molten glass on refractory materials. However, if its content is too high, the melting difficulty of the glass increases, and the transition temperature rises. Therefore, the SiO2 content in this invention is 36-49%, preferably 38-47%, and more preferably 40-45%.

[0033] TiO2 improves the refractive index and dispersion of glass, enhances resistance to devitrification, and reduces the coefficient of thermal expansion. In this invention, the above effects are achieved by containing more than 21% TiO2. If the TiO2 content exceeds 37%, the colorimetric properties of the glass increase, and the transition temperature rises. Therefore, the TiO2 content in this invention is 21–37%, preferably 25–35%, and more preferably 27–33%.

[0034] Li₂O can lower the glass transition temperature and improve the glass's melting properties, but a high Li₂O content is detrimental to the glass's streaking and anti-crystallization properties. Therefore, the Li₂O content in this invention is 0–8%, preferably 0.1–6%, and more preferably 0.5–4%.

[0035] Na₂O can improve the chemical stability of glass, lower its transition temperature and partial dispersion ratio, 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 design requirements. Therefore, the Na₂O content is 6–20%, preferably 8–18%, and more preferably 10.5–16%.

[0036] K2O can adjust the optical constants of glass, which is beneficial for improving its weather resistance; however, if its content is too high, it is not conducive to glass forming and reduces the striation of the glass. Therefore, the K2O content in this invention is 3-15%, preferably 5-12%, and more preferably 6.5-10%.

[0037] In some embodiments, a ratio (Li2O+Na2O+K2O) / TiO2 between the total content of Li2O, Na2O, and K2O (Li2O+Na2O+K2O) and the content of TiO2 (Li2O+Na2O+K2O) is set within the range of 0.4 to 2.0. This improves the chemical stability of the glass and reduces its density and coefficient of thermal expansion. Therefore, a ratio (Li2O+Na2O+K2O) / TiO2 of 0.4 to 2.0 is preferred, more preferably 0.4 to 1.5, further preferably 0.5 to 1.3, and even more preferably 0.7 to 1.0.

[0038] BaO can improve the coefficient of thermal expansion and high-temperature viscosity of glass. However, if its content is too high, it will worsen the chemical stability and devitrification resistance of the glass. Therefore, the BaO content is greater than 0 but less than or equal to 10%, preferably 0.5% to 8%, and more preferably 1% to 4.5%.

[0039] In some embodiments, controlling the Li2O / BaO ratio (Li2O / BaO) within the range of 0.15 to 5.0 can improve the streaking and bubble content of the glass while lowering the glass transition temperature. Therefore, a Li2O / BaO ratio of 0.15 to 5.0 is preferred, more preferably 0.2 to 3.0, even more preferably 0.3 to 2.0, and still more preferably 0.4 to 1.5.

[0040] In some embodiments, controlling the ratio of the total SiO2 and BaO content (SiO2+BaO) to the Li2O content (SiO2+BaO) / Li2O within the range of 5.0 to 39.0 can improve the streaking and light transmittance of the glass. Therefore, it is preferable that (SiO2+BaO) / Li2O is 5.0 to 39.0, more preferably (SiO2+BaO) / Li2O is 8.0 to 35.0, further preferably (SiO2+BaO) / Li2O is 10.0 to 30.0, and even more preferably (SiO2+BaO) / Li2O is 15.0 to 26.0.

[0041] In some embodiments, controlling the ratio of TiO2 content to BaO content (TiO2 / BaO) within the range of 3.0 to 30.0 can improve the weather resistance and bubble resistance of the glass and prevent the transition temperature from rising. Therefore, a TiO2 / BaO ratio of 3.0 to 30.0 is preferred, a TiO2 / BaO ratio of 4.0 to 15.0 is more preferred, a TiO2 / BaO ratio of 5.0 to 10.0 is even more preferred, and a TiO2 / BaO ratio of 5.5 to 9.0 is still preferred.

[0042] In some embodiments, controlling the BaO / K2O ratio (BaO / K2O) to be below 0.95 is beneficial for reducing the glass transition temperature and improving its weather resistance. Therefore, a BaO / K2O ratio of 0.95 or below is preferred, more preferably 0.1 to 0.9, further preferably 0.2 to 0.8, and even more preferably 0.3 to 0.7. Furthermore, controlling the BaO / K2O ratio within the range of 0.46 to 0.65 can further optimize the glass's striations. Therefore, a BaO / K2O ratio of 0.46 to 0.65 is even more preferred.

[0043] SrO can increase the refractive index of glass and improve its resistance to devitrification, but if its content is too high, the chemical stability of the glass will decrease. Therefore, the SrO content is 0-5%, preferably 0-3%, and more preferably 0-2%. In some embodiments, it is even more preferable that the glass does not contain SrO.

[0044] CaO can increase the refractive index of glass and optimize its abrasion resistance, but if the CaO content is too high, it will lead to a decrease in the glass's resistance to crystallization. Therefore, the CaO content is 0-5%, preferably 0-3%, and more preferably 0-2%. In some embodiments, it is even more preferable that the glass does not contain CaO.

[0045] MgO can adjust the optical constants of glass and improve its chemical stability. However, if its content is too high, the glass's devitrification resistance will decrease. Therefore, the MgO content is 0-5%, preferably 0-3%, and more preferably 0-2%. In some embodiments, it is even more preferable that the glass does not contain MgO.

[0046] B2O3 improves the meltability of glass, but when its content is too high, the chemical stability and devitrification resistance of the glass decrease. Therefore, the content of B2O3 in this invention is 0-4%, preferably 0-3%, and more preferably 0-2%. In some embodiments, it is further preferred that the glass does not contain B2O3.

[0047] Ln2O3 (Ln2O3 is one or more of La2O3, Gd2O3, Y2O3, and Yb2O3) can improve the refractive index and chemical stability of glass, and is an optional component in the optical glass of the present invention. By controlling the content of Ln2O3 to below 4%, the devitrification resistance of the glass can be prevented from decreasing. Therefore, in the optical glass of the present invention, the upper limit of the Ln2O3 content range is 4%, preferably 3%, and more preferably 2%. In some embodiments, it is further preferred that Ln2O3 is not present.

[0048] 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, making it prone to inclusions and reducing light transmittance, while also decreasing the glass's resistance to crystallization. Therefore, the ZrO2 content is 0–5%, preferably 0–3%, and more preferably 0–2%.

[0049] In some embodiments, controlling the ratio of the total SiO2 and ZrO2 content (SiO2+ZrO2) to the TiO2 content (SiO2+ZrO2) / TiO2 within the range of 1.0 to 2.2 can improve the glass's resistance to crystallization and optimize its light transmittance and density. Therefore, it is preferable that (SiO2+ZrO2) / TiO2 is 1.0 to 2.2, more preferably (SiO2+ZrO2) / TiO2 is 1.1 to 2.0, further preferably (SiO2+ZrO2) / TiO2 is 1.2 to 1.8, and even more preferably (SiO2+ZrO2) / TiO2 is 1.2 to 1.6.

[0050] Nb₂O₅ is a high-refractive-index, high-dispersion component that can improve the devitrification resistance of glass and reduce its coefficient of thermal expansion. However, if the Nb₂O₅ content is too high, the weather resistance and light transmittance of the glass decrease, and the glass transition temperature increases. Therefore, in this invention, the Nb₂O₅ content is 0–4%, preferably 0–3%, and more preferably 0–2%. In some embodiments, it is further preferred that the glass does not contain Nb₂O₅.

[0051] In some embodiments, controlling the ratio of the total content of Nb2O5 and ZrO2 (Nb2O5+ZrO2) to the content of Li2O (Nb2O5+ZrO2) / Li2O to 1.8 or less can improve the chemical stability of the glass and prevent the glass from deteriorating in terms of anti-crystallization and streaking. Therefore, it is preferable that (Nb2O5+ZrO2) / Li2O is 1.8 or less, more preferably (Nb2O5+ZrO2) / Li2O is 1.5 or less, further preferably (Nb2O5+ZrO2) / Li2O is 1.0 or less, and even more preferably (Nb2O5+ZrO2) / Li2O is 0.5 or less.

[0052] 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 0-4%, preferably 0-3%, and more preferably 0-2%. In some embodiments, it is further preferred that the glass does not contain WO3.

[0053] In some embodiments, by controlling the ratio (Nb2O5+WO3) / BaO between the total content of Nb2O5 and WO3 (Nb2O5+WO3) and the content of BaO to 1.0 or less, the chemical stability and light transmittance of the glass can be improved, and the glass transition temperature can be prevented from rising. Therefore, it is preferable that (Nb2O5+WO3) / BaO is 1.0 or less, more preferably (Nb2O5+WO3) / BaO is 0.8 or less, further preferably (Nb2O5+WO3) / BaO is 0.5 or less, and even more preferably (Nb2O5+WO3) / BaO is 0.2 or less.

[0054] ZnO can improve the chemical stability of glass and reduce its high-temperature viscosity and transition temperature. However, if the ZnO content is too high, the glass's resistance to crystallization decreases, and its high-temperature viscosity is low, making glass forming difficult. Therefore, the ZnO content is 0–10%, preferably 0.1–8%, and more preferably 0.5–6.5%.

[0055] In some embodiments, controlling the ratio of ZnO content to Li2O content (ZnO / Li2O) to below 6.0 allows the glass to achieve a lower transition temperature while improving its striations. Therefore, a ZnO / Li2O ratio of 6.0 or below is preferred, and a ratio of 5.0 or below is more preferable. Furthermore, controlling the ZnO / Li2O ratio within the range of 0.1 to 3.0 can further optimize the glass's resistance to crystallization and bubble formation. Therefore, a ZnO / Li2O ratio of 0.1 to 3.0 is further preferred, even more preferred is 0.1 to 1.5, and still more preferred is 0.2 to 1.0.

[0056] In some embodiments, the ratio of SiO2 content to the total content of BaO, SrO, CaO, MgO, ZnO, and Nb2O5 (BaO+SrO+CaO+MgO+ZnO+Nb2O5), SiO2 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5), is in the range of 4.5 to 40.0, which can improve the glass's resistance to crystallization and bubble formation, and reduce the glass's coefficient of thermal expansion. Therefore, the preferred SiO2 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5) ratio is 4.5 to 40.0, more preferably 6.0 to 30.0, even more preferably 7.0 to 20.0, and still more preferably 8.6 to 12.0.

[0057] In this invention, Al2O3 reduces the coefficient of thermal expansion of glass and improves its thermal stability; however, excessive Al2O3 content will lead to an increase in the glass transition temperature and a rise in 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 0–2%.

[0058] P2O5 can improve the devitrification resistance of glass, but excessive P2O5 content will deteriorate the chemical stability of the glass. Therefore, the P2O5 content is 0-4%, preferably 0-3%, and more preferably 0-1%. In some embodiments, it is even more preferable that P2O5 is not present.

[0059] In this invention, one or more components containing 0-1% of Sb2O3, SnO2, SnO, and CeO2 are used as clarifiers to improve the clarification effect and bubble content of glass. Preferably, the content of the clarifier is 0-0.5%, and more preferably, the content of the clarifier is 0-0.2%.

[0060] F can be used to adjust the refractive index of glass and reduce the temperature coefficient of refractive index. However, its volatilization during production causes environmental pollution, and it can also create inhomogeneities due to its volatilization from the glass surface in the forming temperature range, reducing glass quality and the consistency of optical constants. Therefore, the content of F is 0-3%, preferably 0-2%, and more preferably 0-1%. In some embodiments, it is further preferred that F is not present.

[0061] <Components that should not be present>

[0062] 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.

[0063] 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.

[0064] 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.

[0065] The performance of the optical glass of the present invention will be described below:

[0066] <Refractive Index and Abbe Number>

[0067] 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.

[0068] In some embodiments, the refractive index (n) of the optical glass of the present invention d The upper limit of ) is 1.72, the preferred upper limit is 1.71, and the more preferred upper limit is 1.70.

[0069] In some embodiments, the refractive index (n) of the optical glass of the present invention d The lower limit is 1.65, the preferred lower limit is 1.66, and the more preferred lower limit is 1.67.

[0070] In some embodiments, the Abbe number (ν) of the optical glass of the present invention d The upper limit of ) is 34, the preferred upper limit is 33, and the more preferred upper limit is 32.

[0071] In some embodiments, the Abbe number (ν) of the optical glass of the present invention d The lower limit is 27, the preferred lower limit is 28, and the more preferred lower limit is 29.

[0072] <Colorization>

[0073] 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.

[0074] The same applies to λ5.

[0075] In some embodiments, the λ of the optical glass of the present invention 80 For wavelengths below 420nm, λ is preferred. 80 For wavelengths below 415nm, λ is preferred. 80 For wavelengths below 410nm, λ is further preferred. 80 It is below 405nm.

[0076] In some embodiments, the λ5 of the optical glass of the present invention is 385 nm or less, preferably 380 nm or less, more preferably 375 nm or less, and even more preferably 370 nm or less.

[0077] <Stability under water resistance>

[0078] Water resistance stability of optical glass (D) W (Powder method) Tested according to the method specified in GB / T 17129.

[0079] 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.

[0080] <Stability under acid conditions>

[0081] Acid resistance stability of optical glass (D) A (Powder method) Tested according to the method specified in GB / T 17129.

[0082] In some embodiments, the acid resistance stability (D) of the optical glass of the present invention is... A There are two or more categories, with category 1 being preferred.

[0083] <Upper limit temperature for crystallization>

[0084] The anti-crystallization properties of optical glass were determined using the gradient furnace method. Glass samples measuring 180×10×10 mm were prepared, polished on the sides, and placed in a furnace with a temperature gradient (10℃ / cm) and a maximum temperature zone of 1200℃ for 4 hours. After being removed and allowed to cool naturally to room temperature, the glass was observed for crystallization under a microscope. The highest temperature at which crystals appeared was defined as the upper limit temperature for crystallization. A lower upper limit temperature indicates better anti-crystallization properties.

[0085] In some embodiments, the upper limit temperature for crystallization of the optical glass of the present invention is 980°C or below, preferably 950°C or below, more preferably 920°C or below, and even more preferably 900°C or below.

[0086] Coefficient of thermal expansion

[0087] The coefficient of thermal expansion of optical glass (α) 100 / 300℃ Data were tested at 100–300°C according to the method specified in GB / T7962.16-2010.

[0088] In some embodiments, the coefficient of thermal expansion (α) of the optical glass of the present invention is... 100 / 300℃ ) is 150×10 -7 / K or less, preferably 140×10 -7 / K or less, preferably 135×10 -7 / K or below.

[0089] <Density>

[0090] The density (ρ) of optical glass is tested according to the method specified in GB / T7962.20-2010.

[0091] In some embodiments, the density (ρ) of the optical glass of the present invention is 3.20 g / cm³. 3 The preferred value is 3.10 g / cm³. 3 The following is a preferred value: 3.00 g / cm³ 3 The following is a further preferred value: 2.95 g / cm³ 3 the following.

[0092] <Transition Temperature>

[0093] Transition temperature of optical glass (T) g Test according to the method specified in GB / T7962.16-2010.

[0094] In some embodiments, the transition temperature (T) of the optical glass of the present invention is... g The temperature is 540°C or below, preferably 530°C or below, more preferably 520°C or below, and even more preferably 515°C or below.

[0095] <Weather resistance>

[0096] The weather resistance (CR) test method for optical glass is as follows: The sample is placed in a test chamber with a relative humidity of 90% saturated water vapor, and the temperature is alternately cyclical every 1 hour at 40–50°C, for 15 cycles. Weather resistance is classified according to the change in turbidity before and after the sample placement. The weather resistance classification is shown in Table 1.

[0097] Table 1.

[0098]

[0099] In some embodiments, the weather resistance (CR) of the optical glass of the present invention is Class 2 or above, preferably Class 1.

[0100] <Effervescence>

[0101] The bubble content of optical glass shall be tested according to the method specified in GB / T7962.8-2010.

[0102] In some embodiments, the bubble degree of the optical glass of the present invention is grade A or above, preferably grade A0 or above, and more preferably grade A. 00 class.

[0103] <Stripe>

[0104] The streaking of the glass of this invention is tested using the following method: a streaking meter consisting of a point light source and a lens is used to compare the glass with a standard sample from the direction in which the streaks are most easily visible. The results are divided into four grades: A, B, C, and D. Grade A indicates no streaks visible to the naked eye under specified testing conditions; Grade B indicates fine and dispersed streaks under specified testing conditions; Grade C indicates slight parallel streaks under specified testing conditions; and Grade D indicates coarse streaks under specified testing conditions.

[0105] In some embodiments, the striation of the optical glass of the present invention is grade C or above, preferably grade B or above, and more preferably grade A.

[0106] [Manufacturing Method]

[0107] 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 oxides, hydroxides, fluorides, boric acid, and various salts (carbonates, nitrates, sulfates, phosphates, metaphosphates), etc. After being batched according to conventional methods, the batched charge is placed into a melting furnace (such as a platinum, gold, or platinum alloy crucible) at 1000–1400°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.

[0108] [Glass preforms and optical components]

[0109] 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.

[0110] 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.

[0111] 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.

[0112] 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.

[0113] [Optical Instruments]

[0114] 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.

[0115] Example

[0116] <Example of Optical Glass>

[0117] To further illustrate and explain the technical solution of the present invention, the following non-limiting embodiments are provided.

[0118] In this embodiment, optical glass with the composition shown in Tables 2 to 4 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 2 to 4.

[0119] Table 2.

[0120]

[0121]

[0122] Table 3.

[0123]

[0124]

[0125] Table 4.

[0126]

[0127]

[0128] <Example of Glass Prefabricated Components>

[0129] The glass obtained from optical glass Examples 1 to 21# is used, for example, by grinding, or by molding such as hot pressing or precision stamping, to produce 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.

[0130] <Optical Component Examples>

[0131] 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.

[0132] 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.

[0133] <Examples of Optical Instruments>

[0134] 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: 36–49%; TiO2: 21–37%; Na2O: 6–20%; K2O: 3–15%; BaO: greater than 0 but less than or equal to 10%.

2. The optical glass according to claim 1, characterized in that, Its components, expressed as a weight percentage, also contain: Li₂O: 0–8%; and / or ZnO: 0–10%; and / or SrO: 0–5%; and / or CaO: 0–5%; and / or MgO: 0–5%; and / or B₂O₃: 0–4%; and / or Ln₂O₃: 0–4%; and / or ZrO₂: 0–5%; and / or Nb₂O₅: 0–4%; and / or WO₃: 0–4%; and / or Al₂O₃: 0–4%; and / or P₂O₅: 0–4%; and / or clarifying agent: 0–1%; and / or F: 0–3%, wherein the Ln₂O₃ is one or more of La₂O₃, Gd₂O₃, Y₂O₃, and Yb₂O₃, and the clarifying agent is one or more of Sb₂O₃, SnO₂, SnO, and CeO₂.

3. Optical glass, characterized in that, Its composition is expressed as a weight percentage: SiO2: 36-49%; TiO2: 21-37%; Na2O: 6-20%; K2O: 3-15%; BaO: greater than 0 but less than or equal to 10%; Li2O: 0-8%. ZnO: 0~10%; SrO: 0~5%; CaO: 0-5%; MgO: 0~5%; B2O3: 0~4%; Ln2O3: 0~4%; ZrO2: 0~5%; Nb2O5: 0~4%; WO3: 0~4%; Al2O3: 0~4%; P2O5: 0~4%; Clarifying agent: 0-1%; F: Composition of 0-3%, wherein the Ln2O3 is one or more of La2O3, Gd2O3, Y2O3, and Yb2O3, and the clarifying agent is one or more of Sb2O3, SnO2, SnO, and CeO2.

4. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as weight percentages, wherein: (SiO2+ZrO2) / TiO2 is 1.0 to 2.2, preferably (SiO2+ZrO2) / TiO2 is 1.1 to 2.0, more preferably (SiO2+ZrO2) / TiO2 is 1.2 to 1.8, and even more preferably (SiO2+ZrO2) / TiO2 is 1.2 to 1.

6.

5. 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) / BaO is 1.0 or less, preferably (Nb2O5+WO3) / BaO is 0.8 or less, more preferably (Nb2O5+WO3) / BaO is 0.5 or less, and even more preferably (Nb2O5+WO3) / BaO is 0.2 or less.

6. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: Li2O / BaO is 0.15 to 5.0, preferably Li2O / BaO is 0.2 to 3.0, more preferably Li2O / BaO is 0.3 to 2.0, and even more preferably Li2O / BaO is 0.4 to 1.

5.

7. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: TiO2 / BaO is 3.0 to 30.0, preferably TiO2 / BaO is 4.0 to 15.0, more preferably TiO2 / BaO is 5.0 to 10.0, and even more preferably TiO2 / BaO is 5.5 to 9.

0.

8. 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 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5) is 4.5 to 40.0, preferably SiO2 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5) is 6.0 to 30.0, more preferably SiO2 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5) is 7.0 to 20.0, and even more preferably SiO2 / (BaO+SrO+CaO+MgO+ZnO+Nb2O5) is 8.6 to 12.

0.

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: (Nb2O5+ZrO2) / Li2O is 1.8 or less, preferably (Nb2O5+ZrO2) / Li2O is 1.5 or less, more preferably (Nb2O5+ZrO2) / Li2O is 1.0 or less, and even more preferably (Nb2O5+ZrO2) / Li2O is 0.5 or less.

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: (Li2O+Na2O+K2O) / TiO2 is 0.4 to 2.0, preferably (Li2O+Na2O+K2O) / TiO2 is 0.4 to 1.5, more preferably (Li2O+Na2O+K2O) / TiO2 is 0.5 to 1.3, and even more preferably (Li2O+Na2O+K2O) / TiO2 is 0.7 to 1.

0.

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: BaO / K2O is 0.95 or less, preferably BaO / K2O is 0.1 to 0.9, more preferably BaO / K2O is 0.2 to 0.8, even more preferably BaO / K2O is 0.3 to 0.7, and even more preferably BaO / K2O is 0.46 to 0.

65.

12. The optical glass according to any one of claims 1 to 3, characterized in that, Its components are expressed as a weight percentage, wherein: (SiO2+BaO) / Li2O is 5.0 to 39.0, preferably (SiO2+BaO) / Li2O is 8.0 to 35.0, more preferably (SiO2+BaO) / Li2O is 10.0 to 30.0, and even more preferably (SiO2+BaO) / Li2O is 15.0 to 26.

0.

13. 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 / Li2O is 6.0 or less, preferably ZnO / Li2O is 5.0 or less, more preferably ZnO / Li2O is 0.1 to 3.0, even more preferably ZnO / Li2O is 0.1 to 1.5, and even more preferably ZnO / Li2O is 0.2 to 1.

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: 38-47%, preferably SiO2: 40-45%; and / or TiO2: 25-35%, preferably TiO2: 27-33%; and / or Na2O: 8-18%, preferably Na2O: 10.5-16%; and / or K2O: 5-12%, preferably K2O: 6.5-10%; and / or BaO: 0.5-8%, preferably BaO: 1-4.5%; and / or Li2O: 0.1- 6%, preferably Li₂O: 0.5-4%; and / or ZnO: 0.1-8%, preferably ZnO: 0.5-6.5%; and / or SrO: 0-3%, preferably SrO: 0-2%, more preferably without SrO; and / or CaO: 0-3%, preferably CaO: 0-2%, more preferably without CaO; and / or MgO: 0-3%, preferably MgO: 0-2%, more preferably without MgO; and / or B₂O₃: 0-3%, preferably B₂O₃: 0- 2%, more preferably free of B2O3; and / or Ln2O3: 0-3%, preferably Ln2O3: 0-2%, more preferably free of Ln2O3; and / or ZrO2: 0-3%, preferably ZrO2: 0-2%; and / or Nb2O5: 0-3%, preferably Nb2O5: 0-2%, more preferably free of Nb2O5; and / or WO3: 0-3%, preferably WO3: 0-2%, more preferably free of WO3; and / or Al2O3: 0-3%, preferably Al L2O3: 0-2%; and / or P2O5: 0-3%, preferably P2O5: 0-1%, more preferably without P2O5; and / or clarifying agent: 0-0.5%, clarifying agent: 0-0.2%; and / or F: 0-2%, preferably F: 0-1%, more preferably without F, wherein the Ln2O3 is one or more of La2O3, Gd2O3, Y2O3, and Yb2O3, and the clarifying agent is one or more of Sb2O3, SnO2, SnO, and CeO2.

15. 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 is 1.65–1.72, preferably 1.66–1.71, and more preferably 1.67–1.70; d The value is 27 to 34, preferably 28 to 33, and more preferably 29 to 32.

16. 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 420nm, λ is preferred. 80 For wavelengths below 415nm, λ is preferred. 80 For wavelengths below 410nm, λ is further preferred. 80 The wavelength is 405 nm or less; and / or λ5 is 385 nm or less, preferably 380 nm or less, more preferably 375 nm or less, and even more preferably 370 nm or less; and / or water resistance stability D W It is classified as Class 2 or above, preferably Class 1; and / or acid resistance stability D A It is classified as Class 2 or more, preferably Class 1; and / or the upper limit temperature for crystallization is 980°C or below, preferably 950°C or below, more preferably 920°C or below, and even more preferably 900°C or below; and / or the coefficient of thermal expansion α 100 / 300℃ 150×10 -7 / K or less, preferably 140×10 -7 / K or less, preferably 135×10 -7 / K below; and / or density ρ of 3.20 g / cm³ 3 The preferred value is 3.10 g / cm³. 3 The following is more preferably 3.00 g / cm³. 3 The following is a further preferred value: 2.95 g / cm³ 3 The following; and / or transition temperature T g The temperature is below 540°C, preferably below 530°C, more preferably below 520°C, and even more preferably below 515°C; and / or the weather resistance CR is Class 2 or above, preferably Class 1; and / or the bubble density is Grade A or above, preferably Grade A0 or above, more preferably Grade A. 00 Grade; and / or stripe density of grade C or above, preferably grade B or above, more preferably grade A.

17. A glass precast component, characterized in that, It is made of the optical glass described in any one of claims 1 to 16.

18. An optical element, characterized in that, It is made of optical glass as described in any one of claims 1 to 16, or of glass preform as described in claim 17.

19. An optical instrument, characterized in that, It contains the optical glass according to any one of claims 1 to 16, and / or contains the optical element according to claim 18.

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