Low-density, high-refractive index glass

Abstract

To provide optical glass having a high refractive index and, at the same time, the lowest possible density. [Solution] Refractive index n greater than 1.85 d ν, Abbe number less than 35 d , and temperatures below 1350℃ T max An optical glass having the following properties, containing at least SiO2 and TiO2, and comprising less than 30.0 mol% SiO2, less than 2.0 mol% Nb2O5, less than 17 mol% BaO, and less than 5.0 mol% Ln2O3, where Ln2O3 = Y2O3, La2O3, Gd2O3 and / or Yb2O3.

Description

Technical Field

[0001] The present invention relates to optical glasses having a refractive index greater than 1.85, glass articles comprising said optical glasses, and in particular to the fields of optical components and lenses, meta-optical components, and their use in "Augmented Reality" (English "Augmented reality").

Background Art

[0002] The present invention relates to glasses that can be used in the field of Augmented Reality (AR). High-refractive-index glasses, i.e., glasses having a high refractive index, are advantageous for AR glasses because the Field of View (FoV) increases. On the other hand, the density of such glasses often increases excessively with the increase in refractive index. This means that even if the wafer can be made thinner for AR applications, the glasses of the glasses become significantly heavier, thereby making the long-term wearing of the AR glasses uncomfortable. There is a tendency to shift from the form of standard glasses in the headset, which should be worn for longer periods or always like normal glasses, so it is necessary to lighten the glasses. This weight reduction is also advantageous for many other fields of use, because camera optical components in the field of digital single-lens reflex (DSLR) are also very bulky or very heavy in many cases, thereby significantly increasing the output demand of the autofocus battery.

[0003] Some conventional glasses are derived from niobium phosphate or titanium phosphate systems, and therefore contain large proportions of P2O5 and niobium or titanium. These glasses are partially problematic in production because, in phosphate systems which already act as reducers, oxygen loss due to excessively high melting and clarification temperatures, for example, results in a lower oxidation state. In the case of niobium, this is an oxidation state of less than V, and in the case of titanium, it is an oxidation state of less than IV. This can result in discoloration ranging from dark brown to black in niobium systems, or from blue, yellowish-green to brown to black in titanium systems. Furthermore, titanium significantly increases the crystallinity tendency, which is a known problem with existing high-refractive index glasses in the heavy flint field, in which case, for example, they are no longer reworkable. In contrast to niobium, even titanium with the highest oxidation state is absorbed at the edge of the visible region, which causes the known yellowing of barium titanium silicate in the case of high content.

[0004] Furthermore, niobium phosphate glasses, such as high-refractive index heavy flints or lanthanum heavy flints, not only tend to crystallize at the interface but also exhibit very rapid crystal growth, which can make subsequent cooling (stress cooling or refractive index adjustment) critical for the pre-nucleated glass. Moreover, these glasses are relatively brittle and therefore difficult to polish into very thin wafers.

[0005] On the other hand, weather resistance is relatively good, at least for niobium phosphate glass, despite its P2O5 content. Its density is very low relative to its high refractive index, which enhances wearing comfort. These characteristics are well known from the literature.

[0006] Commercially available lantern flint systems within the refractive index range important for AR applications have a refractive index of n dThese glasses have a significantly unfavorable combination of properties and density. The relatively high density and high Abbe number of these glasses are due in particular to the high content of lanthanum oxide. Furthermore, such glasses have relatively high hardness, and the long polishing time increases the cost of wafer manufacturing. In some cases, the cost of the raw glass is already significantly high because raw materials from the rare earth region, tungsten oxide, tantalum oxide, and other expensive raw materials are used in the production of the raw materials. In the field of heavy flint, Nb2O5 is often the cost driver of the mixture, while other raw materials are relatively inexpensive in comparison, even in terms of optical quality. Furthermore, available lanthanum heavy flint usually does not contain alkali metal oxides and therefore cannot be chemically strengthened. However, in some application areas, it may be advantageous to enhance the mechanical stability of optical components (e.g., spectacle glass) that may become increasingly thin for AR applications through chemical strengthening.

[0007] Many heavy flint glasses in this region of the Abbe diagram, such as P-SF glass, have problems on the one hand due to their batch cost, and furthermore, they are very soft (=easily scratched) due to their high Bi2O3 content, and have unfavorable UV edge transmission, for example, an insufficiently steep UV edge and / or a shifted UV edge in the long-wavelength region of the spectrum. In particular, P-SF glass is also manufactured in batches in platinum crucibles, which can lead to problems associated with platinum alloys and reduction from Bi(III) to Bi(0) in the bath.

[0008] As mentioned above, there are several types of glass that are more or less suitable, but they are usually either in a range of refractive indices that are still too low (typical heavy flint glass) or are difficult to process or work with (typical lantern heavy flint glass).

[0009] Furthermore, lead-free heavy flint glass containing a relatively high proportion of Nb2O5 is known from the prior art. While Nb2O5 decisively contributes to the high refractive index of these glasses, it has a relatively high density and high raw material cost. [Overview of the project] [Problems that the invention aims to solve]

[0010] The problem of the present invention is to address the issue of high refractive index n d The objective is to provide glass that has the lowest possible density. The glass should exhibit the highest possible internal transmittance, be easily thermoformable, and be easily processable. For this purpose, the hardness should not be too low (resulting in more scratches and microcracks), but also not too high (resulting in longer polishing times and resulting microcracks). The glass should have high chemical durability and be economically feasible to manufacture. [Means for solving the problem]

[0011] In one embodiment, this problem is addressed when the refractive index n is greater than 1.85. d ν, Abbe number less than 35 d , and temperatures below 1350℃ T max The solution is provided by an optical glass having at least SiO2 and TiO2, comprising less than 30.0 mol% SiO2, less than 2.0 mol% Nb2O5, less than 17 mol% BaO, and less than 5.0 mol% Ln2O3, where Ln2O3 = Y2O3, La2O3, Gd2O3 and / or Yb2O3.

[0012] Within the scope of the present invention, glass systems containing TiO2 and SiO2 have been found that are more stable with respect to achievable internal transmittance, have a higher refractive index, and nevertheless have a relatively lower density compared to the niobium phosphate-based or titanium phosphate-based glasses described at the beginning. Furthermore, these glass systems have higher hardness and lower batch costs than the aforementioned niobium phosphate glass.

[0013] The optical glass according to the present invention has a refractive index n greater than 1.85, and preferably 2.05 or less. d It has.

[0014] In a favorable embodiment, refractive index n dis at least 1.87, preferably at least 1.88, preferably at least 1.89, preferably at least 1.90, preferably greater than 1.90, preferably at least 1.92 or at least 1.93, advantageously at least 1.95, advantageously at least 1.960, advantageously at least 1.965, advantageously at least 1.970, advantageously at least 1.975, advantageously at least 1.980, and advantageously at least 1.985. Advantageous n d The upper limit of d can be 2.05, or 2.050, or 2.045, or 2.040, or 2.035, or 2.030, or 2.025, or 2.020. Therefore, the refractive index as a whole is advantageously greater than 1.85 and in the range up to 2.05. The refractive index n d is known to those skilled in the art and in particular indicates the refractive index at a wavelength of about 587.6 nm (the wavelength of the d-line of helium). How to determine the refractive index n d can be determined is known to those skilled in the art.

[0015] Preferably, the refractive index is determined using a refractometer, in particular using a V-block refractometer. In this case, in particular, a sample having a square or approximately square bottom surface (for example, having dimensions of about 20 mm × 20 mm × 5 mm) can be used. When measuring using a V-block refractometer, the sample is usually placed in a V-shaped block prism having a known refractive index. Since the refraction of the incident light ray depends on the difference between the refractive index of the sample and the refractive index of the V-block prism, the refractive index of the sample can be determined. The measurement is preferably carried out at a temperature of 22 °C.

[0016] According to the present invention, the glass has an Abbe number, that is, dispersion (ν d ) less than 35. In an advantageous embodiment, the dispersion is less than 32, preferably less than 30, or less than 25, advantageously less than 24, or less than 23, or less than 22, and / or greater than 18, advantageously greater than 18.5, more preferably greater than 19.0. The dispersion ν d is as known, using a refractometer to measure the refractive index values n d (at about 587.6 nm), n F (at about 486 nm), and nC (At approximately 656 nm) it was identified, ν d =(n d -1) / (n F -n C They are related to each other and calculated accordingly.

[0017] Furthermore, the glass according to the present invention is suitable for temperature T max It has a temperature of ≤1350℃. max T is a composition-dependent variable of glass, indicating the minimum temperature required in the melting process to produce a "complete" molten material from the starting material (e.g., raw material, fragments, etc.). A "complete" molten material exists when there are no molten residues, such as partially melted raw materials and crystals in the molten material. As explained at the beginning, the melting and clarification temperatures must be as low as possible to prevent heat-resistant materials from penetrating the glass and to avoid discoloration of the glass by polyvalent ions at lower oxidation states. This allows for high internal transmittance. Because the melting and clarification temperatures cannot be arbitrarily chosen to achieve the highest possible internal transmittance, there is an upper limit to the melting temperature, and therefore the temperature points listed here are "T". max It is also shown as "T max T is the lowest temperature at which a crystal-free, complete melt can barely be produced. Based on this relationship, T max This is a good measure of the liquidus temperature of glass (see below).

[0018] Within the scope of the present invention, the T of the glass composition max The process was systematically identified in a series of experiments on a laboratory scale, in which the same glass, each with a volume of 20 ml, was melted at different maximum temperatures from the starting components in small crucibles, with a temperature step of 10°C being selected. Subsequently, the melting results were visually evaluated in terms of whether a complete molten material had already been formed or whether residues and / or crystals were still present in the glass, starting from the lowest temperature to the highest.

[0019] T was calculated for the composition in this way. maxThe values ​​could also be reproduced in laboratory melting in larger volumes (e.g., 1 liter). Furthermore, further experiments could be performed on temperature point T max It was shown that the temperature is only slightly higher than the liquidus temperature of the glass. The temperature point T was identified using an easy-to-handle laboratory method. max However, it was found to be a good measure of the liquidus temperature of glass, which is not precisely identified here.

[0020] In an advantageous further configuration of the present invention, T max The temperature is 1330°C or lower, preferably 1320°C or lower, preferably 1310°C or lower, and most preferably 1300°C or lower. Some advantageous variations include a temperature of 1290°C or lower, or 1280°C or lower. max It has.

[0021] In a favorable embodiment, the glass has a glass transition temperature T of 500°C to 800°C. g It has. To be advantageous, T g The temperature is above 540°C, preferably above 560°C, more preferably above 580°C, and / or below 750°C, 700°C, or 650°C. g This may be advantageous in terms of crystallization stability, because by doing so T max This is because the temperature difference becomes smaller, and the glass quickly reaches a stable glassy state. However, despite this, the glass can still be thermoformed and processed well.

[0022] In a favorable embodiment, the glass according to the present invention has a molar ratio of (TiO2 + ZrO2 + 2 × Nb2O5 + 2 × Ta2O5 + 2 × Al2O3 + SiO2 + B2O3) / (R2O + RO + 2 × Ln2O3) of 1.5 to 3.5, where R2O = Li2O, Na2O and / or K2O, RO = MgO, CaO, SrO and / or BaO, and Ln2O3 = Y2O3, La2O3, Gd2O3 and / or Yb2O3. Regarding the ratio of components TiO2, ZrO2, Nb2O5, Ta2O5, Al2O3, SiO2, and B2O3 to the ratio of components R2O, RO, and Ln2O3, it should be noted that the ratio should be selected such that the conditions according to the present invention (TiO2 + ZrO2 + 2 × Nb2O5 + 2 × Ta2O5 + 2 × Al2O3 + SiO2 + B2O3) / (R2O + RO + 2 × Ln2O3) 1.5 to 3.5 are satisfied. Higher ratios carry the risk of undesirable crystallization and / or discoloration of the glass. Ratios that are too low also carry the risk of undesirable crystallization. Advantageously, the glass according to the present invention has a molar ratio of (TiO2+ZrO2+2×Nb2O5+2×Ta2O5+2×Al2O3+SiO2+B2O3) / (R2O+RO+2×Ln2O3) of 1.8 to 3.2, more preferably 2.0 to 3.0, and particularly preferably 2.1 to 2.9.

[0023] In a favorable embodiment, the glass according to the present invention has a molar ratio of 1.5 to 3.5 of (TiO2 + ZrO2 + 2 × Nb2O5 + 2 × Ta2O5 + 2 × Al2O3 + SiO2 + B2O3) / (R2O + Cs2O + RO + 2 × Ln2O3), where R2O = Li2O, Na2O and / or K2O, RO = MgO, CaO, SrO and / or BaO, and Ln2O3 = Y2O3, La2O3, Gd2O3 and / or Yb2O3. Components: TiO2, ZrO2, Nb2O5, Ta2O 5、 Al2O 3、Regarding the ratio of SiO2 and B2O3 to the ratios of components R2O, Cs2O, RO, and Ln2O3, it should be noted that the ratio should be selected so as to satisfy the conditions according to the present invention (TiO2 + ZrO2 + 2 × Nb2O5 + 2 × Ta2O5 + 2 × Al2O3 + SiO2 + B2O3) / (R2O + Cs2O + RO + 2 × Ln2O3) 1.5 to 3.5. Higher ratios carry the risk of undesirable crystallization and / or discoloration of the glass. Ratios that are too low also carry the risk of undesirable crystallization. Advantageously, the glass according to the present invention has a molar ratio of (TiO2 + ZrO2 + 2 × Nb2O5 + 2 × Ta2O5 + 2 × Al2O3 + SiO2 + B2O3) / (R2O + Cs2O + RO + 2 × Ln2O3) of 1.8 to 3.2, more preferably 2.0 to 3.0, and particularly preferably 2.1 to 2.9.

[0024] Advantageously, the optical glass according to the present invention has a viscosity of 4.5 g / cm³. 3 Preferably, 4.3 g / cm³ 3 Preferably, 4.1 g / cm³ 3 More specifically, 4.0 g / cm³ 3 The following is particularly preferred: 3.90 g / cm³ 3 The following, and more preferably 3.85 g / cm³ 3 The following, or 3.8 g / cm³ 3 The density ρ is as follows. Advantageously, the density of the glass according to the present invention is 3.0 g / cm³. 3 ~4.5g / cm 3 Preferably 3.2 g / cm³ 3 ~4.3g / cm 3 Preferably 3.5 g / cm³ 3 ~4.1g / cm 3 Particularly preferred is 3.6 g / cm³ 3 ~4.0g / cm 3 , or 3.6 g / cm³ 3 ~3.85g / cm 3 , or 3.6 g / cm³ 3 ~3.8g / cm 3 That is the case.

[0025] Advantageously, the glass has a density ρ and a refractive index nd Ratio to (ρ / n) d ) 2.0 or less, preferably 1.95 g / cm³ 3 The following is included: In some advantageous embodiments, the glass has density ρ and refractive index n d Ratio to (ρ / n) d ) 1.90 g / cm³ 3 Preferably, 1.89 g / cm³ 3 The following, or 1.88 g / cm³ 3 The following is included: In some advantageous embodiments, the glass has density ρ and refractive index n d Ratio to (ρ / n) d ) 1.87 g / cm³ 3 Preferably, 1.86 g / cm³ 3 The following applies.

[0026] Advantageously, the optical glass according to the present invention has an Abbe number ν d The ratio of (ν) to density ρ d / ρ)4.5cm 3 / g~7.5cm 3 / g, preferably 4.8cm 3 / g~7.0cm 3 / g, or preferably 4.9cm 3 / g~6.5cm 3 / g, particularly preferably 5.0cm 3 / g~6.0cm 3 It contains / g

[0027] Advantageously, the glass has a density of 100 g / cm³. 3 Less than 95 g / cm³ 3 Less than 90 g / cm³ 3 Less than 80 g / cm³ 3 Less than 50 g / cm³, and more favorably 50 g / cm³. 3 It is greater than, preferably 55 g / cm³ 3 It should exceed 60 g / cm³, preferably 60 g / cm³. 3 It is greater than, preferably 65 g / cm³ 3 It is greater than 70 g / cm³, and particularly preferably 70 g / cm³. 3 The Abbe number ν exceeds the Abbe number ν d It has the product of and density ρ.

[0028] According to the present invention, the glass has an SiO2 content of less than 30.0 mol%. SiO2 is a glass-forming agent. While this oxide contributes significantly to chemical durability, it also increases the processing temperature. If it is used in very large quantities, the refractive index according to the present invention cannot be achieved. Advantageously, the glass contains at least 10.0 mol%, preferably at least 12.0 mol%, preferably at least 13.0 mol%, and particularly preferably at least 15.0 mol% of SiO2. The glass has less than 30.0 mol%, advantageously 28.0 mol% or less, preferably 25.0 mol% or less, and particularly preferably 23.0 mol% or less of SiO2. In an advantageous embodiment, the glass contains 10.0 mol% to <30.0 mol%, advantageously 12.0 mol% to 28.0 mol%, preferably 13.0 mol% to 25.0 mol%, and more preferably 15.0 mol% to 23.0 mol% of SiO2.

[0029] B2O3 also functions as a glass-forming agent. In the glass system according to the present invention, it has a temperature point T max This can contribute to reducing [the value]. Advantageously, the glass contains 0 mol% to 8.0 mol%, preferably 0 mol% to 5.0 mol%, or 1.0 mol% to 5.0 mol% of B2O3. Some advantageous variants may contain at least 1.0 mol%, or at least 1.5 mol%, or at least 2.0 mol% of B2O3. Advantageously, the B2O3 content is limited to 7.0 mol% or less, preferably 6.5 mol% or less, preferably 5.0 mol% or less, more preferably 4.0 mol% or less, and preferably 3.0 mol% or less. Some advantageous variants contain 0.5 mol% or less, advantageously less than 0.1 mol% of B2O3. Some advantageous variants are B2O3-free.

[0030] Since the glass-forming agent stabilizes the glass, it is advantageous to select the glass-forming agent so that the total amount is not too low, while limiting the content to obtain glass with a high refractive index. Therefore, advantageously, the glass of the present invention has a total amount of SiO2 and B2O3 of 12.0 mol% to 28.0 mol%, preferably 12.0 mol% to 25.0 mol%, and preferably 15.0 mol% to 23.0 mol%.

[0031] The glass of the present invention may contain Nb2O5, but the use of Nb2O5 may result in increased batch costs and increased glass density. Therefore, according to the present invention, the Nb2O5 content is limited to less than 2.0 mol%, preferably less than 1.5 mol%, more preferably less than 1.0 mol%, and particularly preferably less than 0.5 mol%. A preferred embodiment of the glass of the present invention is essentially Nb2O5-free.

[0032] Advantageously, the glass contains at least 35.0 mol%, preferably at least 37.0 mol%, preferably at least 40.0 mol%, or preferably at least 43.0 mol%, and / or 65.0 mol% or less, preferably 61.0 mol% or less, or 60.0 mol% or less, and more preferably 55.0 mol% or less of TiO2. In some advantageous embodiments, the glass contains 35.0 mol% to 65.0 mol%, preferably 40.0 mol% to 60.0 mol%, and more preferably 43.0 mol% to 55.0 mol% of TiO2.

[0033] Advantageously, the glass contains BaO in addition to TiO2, wherein the glass has a total content of BaO and TiO2 of at least 35.0 mol%, at least 40.0 mol%, at least 42.0 mol%, at least 45.0 mol%, more preferably at least 50.0 mol%, and / or 70.0 mol% or less, at least 65.0 mol%, preferably 63.0 mol%, or 60.0 mol% or less.

[0034] Optionally, the glass may contain Al2O3. Al2O3 can contribute to the chemical durability of the glass. The glass may contain 0 to 8.0 mol%, or 0 to 5.0 mol%, or up to 3.0 mol%, or up to 2.0 mol%, or up to 1.0 mol% of Al2O3. Some advantageous embodiments contain less than 0.5 mol% of Al2O3. A preferred variant is Al2O3-free. Some advantageous variants may contain 0.5 mol% to 3.0 mol%, preferably 0.75 mol% to 2.5 mol%, or 2.0 mol% to 5.0 mol%.

[0035] The glass may contain ZrO2. While ZrO2 contributes to achieving a high refractive index, it also increases the crystallization tendency of the glass; therefore, its content is advantageously limited to 7.5 mol% or less, preferably 6.5 mol% or less, similarly preferably 5.5 mol% or less, or 5.0 mol% or less. In some advantageous embodiments, the glass contains at least 0.5 mol%, preferably at least 1.5 mol%, preferably at least 2.5 mol% or 3.0 mol% of ZrO2. In some embodiments, the glass contains 0.5 mol% to 7.5 mol%, preferably 1.5 mol% to 6.5 mol%, more preferably 2.5 mol% to 5.5 mol%, and particularly preferably 3.0 mol% to 5.0 mol% of ZrO2. Some embodiments may be ZrO2-free.

[0036] Advantageously, the glass contains Li2O, Na2O, and / or K2O. Preferably, the glass has a total R2O content (R2O = Li2O, Na2O, and / or K2O) of at least 1.0 mol%, more preferably at least 2.0 mol%, particularly preferably at least 3.0 mol%, or at least 4.0 mol%, and / or 20.0 mol% or less, advantageously 17.0 mol% or less, more preferably 15 mol% or less, and particularly preferably 14 mol% or less. Advantageously, the glass has a total R2O content of 1.0 mol% to 20 mol%, preferably 2.0 mol% to 17.0 mol%, more preferably 3.0 mol% to 15.0 mol%, and similarly preferably 4.0 mol% to 14 mol%. While the above alkali metal oxides contribute to good processability, excessively high content can reduce chemical durability and significantly lower the refractive index. Some embodiments may be R2O-free.

[0037] In some advantageous embodiments, the glass comprises one of Li2O, Na2O, and K2O. In some advantageous embodiments, the glass comprises at least two of Li2O, Na2O, and K2O. In some advantageous embodiments, the glass comprises Na2O and at least one of Li2O and K2O. In some advantageous embodiments, the glass comprises Li2O, Na2O, and K2O.

[0038] In some embodiments, the glass contains Li2O. Since Li2O can corrode the materials of the crucible and tank, its content is advantageously limited. The Li2O content is preferably in the range of 0 mol% to 10.0 mol%, advantageously 0.5 mol% to 7.0 mol%, more preferably 1.0 mol% to 5.0 mol%, or 1.5 mol% to 3.0 mol%, or 2.0 mol%. In some advantageous embodiments, the glass is Li2O-free.

[0039] In some advantageous embodiments, the glass contains Na2O. The Na2O content is preferably in the range of 0.5 mol% to 18.0 mol%, or 0.5 mol% to 15.0 mol%, preferably 1.0 mol% to 13.5 mol%, or 12.5 mol%. In some advantageous embodiments, the glass contains at least 1.0 mol%, preferably at least 1.5 mol%, preferably at least 2.0 mol%, at least 3.0 mol%, and / or 18.0 mol% or less, or 15.0 mol% or less, preferably 13.5 mol% or less, or 12.5 mol% or less, preferably 11.0 mol% or less of Na2O. In some advantageous embodiments, the glass may be Na2O-free.

[0040] In some advantageous embodiments, the glass contains K2O, where the K2O content is less than 5.0 mol%, preferably less than 3.0 mol%, preferably greater than 0 mol% to 5.0 mol%, and preferably in the range of 0.5 mol% to 3.0 mol%. In some advantageous embodiments, the glass is K2O-free.

[0041] In an advantageous embodiment, the glass contains at least one alkaline earth oxide RO, where RO is selected from MgO, CaO, SrO, and / or BaO. Advantageously, the glass contains at least BaO. Advantageously, the glass contains BaO and at least one of MgO, CaO, and SrO. CaO and SrO stabilize the glass against crystallization by lowering the melting temperature without reducing chemical durability as much as alkali metal oxides.

[0042] Advantageously, the total content of MgO, CaO, and SrO is in the range of 2.0 mol% to 25.0 mol%. In some advantageous variants, the glass contains a total content of MgO, CaO, and SrO in the range of 5.0 mol% to 22.0 mol%. In some advantageous embodiments, the total content of MgO, CaO, and SrO is in the range of 5.0 to 10.0 mol%. In some advantageous embodiments, the total content of MgO, CaO, and SrO is in the range of 12.0 mol% to 22.0 mol%.

[0043] In some advantageous embodiments, the glass contains BaO and at least one of MgO, CaO, and SrO, preferably MgO and / or CaO. Preferably, the glass has a total RO content (RO = MgO, CaO, SrO, and / or BaO) of 5.0 mol% to 25.0 mol%, preferably 8.0 mol% to 31.0 mol%, preferably 10.0 mol% to 28.0 mol%, preferably 12.0 mol% to 24.0 mol%.

[0044] Advantageously, the glass contains BaO. Advantageously, the glass contains BaO in an amount greater than 0 mol% to 17.0 mol%, greater than 0 mol% to 15.0 mol%, preferably 1.0 mol% to 12 mol%, or up to 13.0 mol%, and more preferably 2.0 mol% to 11.0 mol%, or up to 13.0 mol%.

[0045] In some advantageous embodiments, the glass contains MgO in a content of more than 0 mol% to 10.0 mol%, preferably 0.5 mol% to 7.5 mol%, or 1.0 mol% to 6.0 mol%. Some advantageous variants contain more than 0 mol% to 3.0 mol%, preferably 1.0 mol% to 3.0 mol% of MgO. Some advantageous variants are MgO-free.

[0046] In an advantageous embodiment, the glass contains CaO. The CaO content is preferably in the range of more than 0 mol% to 30.0 mol%, and preferably 1.0 mol% to 25.0 mol%. In some advantageous embodiments, the glass contains 2.0 mol% to 22.0 mol%, preferably 3.0 mol% to 19.0 mol%, and similarly preferably 5.0 mol% to 15.0 mol% CaO. Some embodiments may be CaO-free.

[0047] The SrO content is preferably in the range of 0 mol% to 5.0 mol%, or 4.0 mol%. In some advantageous embodiments, the SrO content is in the range of 0 mol%, or 1.0 mol% to 3.0 mol%, preferably 1.5 mol% to 2.5 mol%. Some advantageous embodiments are SrO-free.

[0048] Advantageously, the glass contains a total RO+R2O content in the range of 15.0 mol% to 40.0 mol%, preferably 20.0 mol% to 35.0 mol%, and preferably 23.0 mol% to 31.0 mol%. Glass having the above total RO and R2O content exhibits advantageous glass-forming properties. If the RO and R2O content is low, the glass has an undesirably high melting temperature, and if the content is too high, the tendency of the glass to crystallize increases.

[0049] Optionally, the glass may contain ZnO. However, since ZnO is harmful to water and can corrode the tank and crucible, the ZnO content is advantageously limited to less than 10.0 mol%. In an advantageous embodiment, the glass has a ZnO content of 7.5 mol% or less, or 5.5 mol% or less, more preferably 3.5 mol% or less. In some embodiments, the glass has a ZnO content of 0.5 mol% to 7.5 mol%, preferably 0.5 mol% to 5.5 mol%, and more preferably 0.75 mol% to 3.5 mol%. Some advantageous variants are ZnO-free.

[0050] Optionally, the glass may contain Ln2O3 (Ln2O3 = La2O3, Gd2O3, Y2O3, and / or Yb2O3). Generally, these components can be used to increase the refractive index of the glass, but Ln2O3-containing glass typically has a high density. Therefore, the Ln2O3 content is limited to less than 5.0 mol%, advantageously less than 2.0 mol%, preferably less than 1.0 mol%, and particularly preferably less than 0.5 mol%. Preferably, the glass is Ln2O3-free.

[0051] The addition of conventional fining agents is not necessary because the molten material has low viscosity at the temperature required for melting. Nevertheless, if fining agents, such as As2O3, Sb2O3, SO3, F, and / or Cl, are added, their content can be significantly reduced, for example, to <0.1 mol%. Pure physical fining is also possible and advantageous. Optionally, the glass may contain one or more of the following fining components in the proportions indicated in mol%: Sb2O3 0.0~1.0 As2O30.0~1.0 SO30.0~1.0 F 0.0~1.0 Cl 0.0~1.0.

[0052] To contribute to the stabilization of the oxidation state in the case of polyvalent ions, a small amount of sulfate (SO3) may be included in the glass. If it is included, the proportion is at least 0.01 mol%. A higher proportion of sulfate increases the risk of significant bubble formation in the glass and the risk of platinum inclusion in the glass. Therefore, the proportion of sulfate can be advantageously up to 0.5 mol%, advantageously up to 0.1 mol%, and preferably up to 0.05 mol%. Preferably, the glass is SO3-free.

[0053] In some embodiments, F can have a favorable effect on the transmittance of the glass by stabilizing the high oxidation state of the polyvalent ion.

[0054] The glass may contain a small amount of hafnium (HfO2), advantageously up to 0.2 mol%, preferably up to 0.1 mol%, or up to 0.05 mol%. Typically, it is not actively added but enters the glass along with the ZrO2 component via the raw materials. When very pure ZrO2 raw materials are used, the glass is advantageously HfO2-free.

[0055] In a favorable embodiment, the glass comprises the following components in mol%: SiO2 10.0 to <30.0, preferably 12.0 to 28.0 B2O30-8.0, preferably 0-5.0 TiO2 + BaO 35.0~70.0, preferably 40.0~65.0 R2O + RO 15.0~40.0, preferably 20.0~35.0 ZnO < 10.0, preferably ≤ 7.5 Ln2O3 < 2.0, preferably < 1.0 It has.

[0056] In a favorable embodiment, the glass comprises the following components in mol%: SiO2 10.0 to <30.0, preferably 12.0 to 28.0 B2O30-8.0, preferably 0-5.0 TiO2 + BaO 35.0~70.0, preferably 40.0~65.0 R2O 1.0~20.0, preferably 2.0~17.0 RO 8.0~31.0, preferably 10.0~28.0 R2O + RO 15.0~40.0, preferably 20.0~35.0 ZnO ≤ 7.5, preferably ≤ 5.5 ZrO2 0.5~7.5, preferably 1.5~6.5 Ln2O3 < 1.0, preferably 0 It has.

[0057] In a favorable embodiment, the glass comprises the following components in mol%: SiO2 12.0~28.0, preferably 13.0~25.0 B2O30-5.0, preferably 0-4.0 TiO2 + BaO 40.0~65.0, preferably 45.0~63.0 TiO2 35.0~65.0, preferably 40.0~61.0 R2O 2.0~17.0, preferably 3.0~15.0 Li2O 0-10.0, preferably 0-7.0 Na2O 0.5~15.0, preferably 1.0~13.5 K2O 0-5.0, preferably 0-3.0 RO 10.0~28.0, preferably 12.0~24.0 MgO 0-10.0, preferably 0-7.5 CaO 1.0~25.0, preferably 2.0~22.0 SrO 0-5.0, preferably 0-3.0 BaO 1.0~12.0, preferably 2.0~11.0 R2O + RO 20.0~35.0, preferably 23.0~31.0 ZnO 0-5.5, preferably 0-3.5 ZrO2 1.5-6.5, preferably 2.5-5.5 Ln2O3 < 1.0, preferably 0 It has.

[0058] In a favorable embodiment, the glass comprises the following components in mol%: SiO2 15.0~<30.0 B2O30~5.0 TiO2 + BaO 40.0~65.0 R2O 1.0~20.0 RO 8.0~28.0 R2O+RO 20.0~35.0 ZnO ≤ 3.5 ZrO2 0.5~7.5 Ln2O3 < 1.0 It has.

[0059] In a favorable embodiment, the glass comprises the following components in mol%: SiO2 10.0~20.0 B2O30~5.0 TiO2 + BaO 45.0~60.0 R2O < 1.0, preferably 0 RO 25.0~40.0 R2O+RO 25.0~40.0 ZnO ≤ 3.5, preferably ≤ 2.5 ZrO2 2.5~7.5 Ln2O3 < 1.0 It has.

[0060] In a favorable embodiment, the glass comprises at least 95.0 mol%, particularly at least 98.0 mol%, or at least 99.0 mol%, of the components described herein, particularly those listed in the table above. In one embodiment, the glass comprises essentially all of these components.

[0061] Advantageously, the glass is essentially bismuth (Bi2O3) and / or lead (PbO) free. The addition of bismuth disproportionately increases the density of the glass. Furthermore, bismuth ions are reduced to elemental bismuth at relatively low temperatures in the range of 1000°C, which leads to a strong gray coloration of the glass. PbO also negatively impacts the low density and should therefore be avoided. Moreover, it is considered a toxic component.

[0062] Due to the high content of niobium and titanium, expensive components such as tantalum (Ta2O5) and / or tungsten (WO3) and / or germanium (GeO2) are not required, or are required in small amounts, in order to obtain glass with the desired high refractive index.

[0063] Advantageously, the glass is free of phosphates (P2O5) because they significantly reduce the molten material, and the reduction of TiO2 and / or Nb2O5 reduces its transmittance. Furthermore, the reduced molten material can corrode platinum, thereby increasing the infiltration of platinum into the molten material, which leads to increased discoloration or scattering of the glass.

[0064] The glass may optionally contain, with respect to each cation, one or more components selected from cadmium, gallium, germanium, thallium, coloring components (e.g., cobalt, vanadium, chromium, molybdenum, copper, nickel), and combinations thereof. Components such as iron, cerium, manganese, selenium, and / or tellurium may be present in the glass in smaller proportions, for example, as impurities. Iron, cerium, selenium, and tellurium, as well as manganese, can function as redox partners. However, advantageously, these components are not intentionally added to the glass, either individually or in combination.

[0065] In this specification, when it is stated that a glass is free of a certain component or does not contain a particular component, it means that this component may be present in the glass only as an impurity. This means that it is not added in an essential amount. According to the present invention, an essential amount is less than 100 ppm, preferably less than 50 ppm, and most preferably less than 10 ppm (m / m).

[0066] Advantageously, the optical glass has an internal transmittance (t) of at least 80%, preferably at least 85%, more preferably at least 90%, and particularly preferably at least 93%, as measured at a wavelength of 460 nm and a sample thickness of 10 mm. i It has (10 mm, 460 nm).

[0067] Internal transmittance or internal light transmission can be measured by methods well known to those skilled in the art, for example, in accordance with DIN 5036-1:1978. In this specification, the description of internal transmittance relates to a wavelength of 460 nm and a sample thickness of 10 mm. The description of "sample thickness" does not mean that the glass has this thickness, but merely describes the thickness to which the description of internal transmittance relates.

[0068] Unless otherwise specified or it is obvious to those skilled in the art, the measurements described herein are performed at 20°C and 101.3 kPa.

[0069] In one embodiment, the present invention relates to a glass article having or made of glass according to the present invention. The glass article may have various forms. Optionally, the article is • Glass substrates for structural members of optical components, particularly in AR glasses, especially glass substrates as components of laminated substrates. • Wafers, particularly those having a maximum diameter of 5.0 cm to 50.0 cm, or a diameter of 0.7 cm to 50 cm, preferably 3 cm to 45 cm, or 5 cm to 40 cm. Lenses, especially spherical lenses, rod lenses, prisms or aspherical lenses, and / or • Optical waveguides, especially fiber or plate It has the form of.

[0070] In a further embodiment, the glass articles according to the present invention are chemically strengthened glass articles, particularly chemically strengthened glass substrates, chemically strengthened wafers, and / or chemically strengthened lenses. It will be understood by those skilled in the art that these are glass articles comprising chemically strengthenable optical glass according to the present invention.

[0071] Within the scope of this disclosure, chemically strengthenable glass is understood to be glass that can utilize an ion exchange process. In such a process, alkali metal ions are exchanged in the surface layer of a glass article, for example, a wafer. This is done so that a compressive stress region is constructed in the surface layer, which is achieved by exchanging ions with smaller radii for ions with larger radii. To this end, the glass article is immersed in a so-called ion exchange bath, for example, a molten salt, where the ion exchange bath contains ions with larger ionic radii, particularly potassium ions and / or sodium ions, which are transferred to the surface layer of the glass article. Conversely, ions with smaller ionic radii, particularly lithium ions and / or sodium ions, are moved from the surface layer of the glass article to the ion exchange bath.

[0072] This creates a compressive stress region. This can be described by a characteristic magnitude of the compressive stress, also called "compressive stress" or abbreviated as "CS," and the compressive stress depth, also called "layer depth" or abbreviated as "DoL." The compressive stress depth DoL is well known to those skilled in the art and, within the scope of this disclosure, indicates the depth to which the stress curve passes through zero stress.

[0073] Such chemically strengthened glass articles can achieve higher mechanical strength.

[0074] To the advantage of this process, the manufacture of chemically strengthened glass articles involves the following steps: a) In the stage of preparing the glass articles mentioned above, b) A step in which at least one first ion exchange is performed, c) A step in which a second ion exchange is optionally performed. Includes.

[0075] Advantageously, the first ion exchange is carried out for 0.5 to 24 hours, advantageously 1 to 5 hours, more preferably 2 to 8 hours, at a temperature of 350°C to 500°C, preferably 370°C to 450°C, particularly preferably 380°C to 430°C, where the exchange bath contains at least one potassium salt, particularly KNO3 and / or at least one sodium salt, particularly NaNO3.

[0076] In some advantageous embodiments, a second ion exchange is subsequently carried out at a temperature of 350°C to 500°C, preferably 370°C to 450°C, particularly preferably 380°C to 430°C, for a period of 0.5 to 24 hours, advantageously 1 to 5 hours, more preferably 2 to 8 hours, wherein the exchange bath contains at least one potassium salt, particularly KNO3, and / or at least one sodium salt, particularly NaNO3.

[0077] In a further embodiment, the present invention relates to the use of the glass or glass articles described herein in AR glasses, meta-optical components, wafer-level optical components, optical wafer applications, or conventional optical components. Alternatively or additionally, the glass or glass articles described herein can be used as wafers, lenses, or optical waveguides.

[0078] The glass according to the present invention can be melted from commercially available raw materials. For example, the glass can be melted using an apparatus such as that described in German Patent Application No. 10 2020 120168 (DE 10 2020 120168 A1). [Examples]

[0079] The compositions shown in Tables 1-6 below were melted and their properties were investigated.

[0080] Composition and properties: [Table 1]

[0081] [Table 2]

[0082] [Table 3]

[0083] [Table 4]

[0084] [Table 5]

[0085] [Table 6]

[0086] The glass of the examples according to the present invention has a high refractive index, a low density, and an advantageous product of the Abbe number and the density, and has a low T max It has. In the scope of the present invention, it has been found that the glass according to the present invention has a low crystallization tendency.

[0087] Although the present invention has been described using preferred embodiments, the present invention is not limited thereto and can be changed in various ways.

Claims

1. A refractive index n exceeding 1.85 d , an Abbe number ν less than 35 d , and a temperature T of 1350 °C or lower max having, and containing at least SiO 2 and TiO 2 and containing less than 30.0 mol% of SiO 2 , less than 2.0 mol% of Nb 2 O 5 , less than 17 mol% of BaO, and less than 5.0 mol% of Ln 2 O 3 where Ln 2 O 3 = Y 2 O 3 , La 2 O 3 , Gd 2 O 3 and / or Yb 2 O 3 is an optical glass.

2. The glass has a content of 1.5 to 3.5 (TiO 2 +ZrO 2 +2 × Nb 2 O 5 +2 × Ta 2 O 5 +2 × Al 2 O 3 +SiO 2 +B 2 O 3 ) / (R 2 O + RO + 2 × Ln 2 O 3 ) has a molar ratio where R 2 O = Li 2 O, Na 2 O and / or K 2 O, RO = MgO, CaO, SrO and / or BaO, Ln 2 O 3 = Y 2 O 3 La 2 O 3 , Gd 2 O 3 and / or Yb 2 O 3 The optical glass according to claim 1.

3. The glass is 120 g / cm³ 3 Less than 100 g / cm³, preferably 100 g / cm³ 3 Less than 90 g / cm³, particularly preferably 90 g / cm³ 3 Less than 50 g / cm³, and more favorably 50 g / cm³. 3 A value greater than, preferably 55 g / cm³ 3 Amounts exceeding 60 g / cm³, particularly preferably 60 g / cm³. 3 The Abbe number ν exceeds the Abbe number ν d The optical glass according to claim 1 or 2, having the product of and density ρ.

4. The glass is essentially Nb 2 O 5 The optical glass according to any one of claims 1 to 3, which does not contain.

5. The optical glass according to any one of claims 1 to 4, wherein the glass contains more than 0 mol% to 15.0 mol%, preferably 2.0 mol% to 13.0 mol%, of BaO.

6. The glass contains at least 35.0 mol%, preferably at least 40.0 mol%, preferably at least 45.0 mol%, and / or 70.0 mol% or less, preferably 65.0 mol% or less of BaO and TiO. 2 An optical glass according to any one of claims 1 to 5, having the total content of the above.

7. The glass contains 1.0 mol% to 20.0 mol%, preferably 2.0 mol% to 17 mol%, and particularly preferably 3.0 mol% to 15.0 mol% of R 2 Total content of O (R 2 O = Li 2 O, Na 2 O and / or K 2 The optical glass according to any one of claims 1 to 6, having (O).

8. The optical glass according to any one of claims 1 to 7, wherein the glass has a total RO content of 8.0 mol% to 31.0 mol%, preferably 10.0 mol% to 28.0 mol%, (RO = MgO, CaO, SrO and / or BaO), and / or a total MgO, CaO and SrO content of 2.0 mol% to 25.0 mol%, preferably 5.0 mol% to 22.0 mol%,

9. The glass contains 15.0 mol% to 40.0 mol%, preferably 20.0 mol% to 35.0 mol%, and particularly preferably 23.0 to 31.0 mol% RO+R 2 An optical glass according to any one of claims 1 to 8, having a total content of O.

10. The glass contains 0.5 mol% to 7.5 mol%, preferably 1.5 mol% to 6.5 mol%, and more preferably 2.5 mol% to 5.5 mol% of ZrO 2 An optical glass according to any one of claims 1 to 9, comprising:

11. The optical glass according to any one of claims 1 to 10, wherein the glass contains less than 10.0 mol%, preferably 7.5 mol% or less, and particularly preferably 0.5 mol% to 5.5 mol% of ZnO.

12. The aforementioned glass contains the following components in mol%: SiO 2 10.0 to <30.0, preferably 12.0 to 28.0 B 2 O 3 0 to 8.0, preferably 0 to 5.0 TiO 2 +BaO 35.0 to 70.0, preferably 40.0 to 65.0 R 2 O+RO 15.0 to 40.0, preferably 20.0 to 35.0 ZnO < 10.0, preferably ≤ 7.5 Ln 2 O 3 <2.0, preferably <1.0 The optical glass according to any one of claims 1 to 11, including the following:

13. The glass contains 12.0 mol% to 25.0 mol%, preferably 15.0 mol% to 23.0 mol%, of SiO2. 2 and B 2 O 3 An optical glass according to any one of claims 1 to 12, having the total content of the above.

14. The glass contains less than 5.0 mol%, preferably less than 3.0 mol% of K. 2 An optical glass according to any one of claims 1 to 13, having O.

15. The aforementioned glass contains the following components in mol%: SiO 2 10.0 to <30.0, preferably 12.0 to 28.0 B 2 O 3 0 to 8.0, preferably 0 to 5.0 TiO 2 +BaO 35.0 to 70.0, preferably 40.0 to 65.0 R 2 O 1.0 to 20.0, preferably 2.0 to 17.0 RO 8.0 to 31.0, preferably 10.0 to 28.0 R 2 O+RO 15.0 to 40.0, preferably 20.0 to 35.0 ZnO ≤ 7.5, preferably ≤ 5.5 ZrO 2 0.5 to 7.5, preferably 1.5 to 6.5 Ln 2 O 3 <1.0, preferably 0 The optical glass according to any one of claims 1 to 14, including the following:

16. The aforementioned glass contains the following components in mol%: SiO 2 12.0 to 28.0, preferably 13.0 to 25.0 B 2 O 3 0 to 5.0, preferably 0 to 4.0 TiO 2 +BaO 40.0 to 65.0, preferably 45.0 to 63.0 TiO 2 35.0 to 65.0, preferably 40.0 to 61.0 R 2 O 2.0 to 17.0, preferably 3.0 to 15.0 Li 2 O 0 to 10.0, preferably 0 to 7.0 Na 2 O 0.5 to 15.0, preferably 1.0 to 13.5 K 2 O 0 to 5.0, preferably 0 to 3.0 RO 10.0 to 28.0, preferably 12.0 to 24.0 MgO 0 to 10.0, preferably 0 to 7.5 CaO 1.0 to 25.0, preferably 2.0 to 22.0 SrO 0 to 5.0, preferably 0 to 3.0 BaO 1.0 to 12.0, preferably 2.0 to 11.0 R 2 O+RO 20.0 to 35.0, preferably 23.0 to 31.0 ZnO 0 to 5.5, preferably 0 to 3.5 ZrO 2 1.5 to 6.5, preferably 2.5 to 5.5 Ln 2 O 3 <1.0, preferably 0 The optical glass according to any one of claims 1 to 15, including the following:

17. The optical glass according to any one of claims 1 to 16, wherein the glass has an internal transmittance of at least 80%, preferably at least 85%, more preferably at least 90%, and particularly preferably at least 93%, as measured at a wavelength of 460 nm and a sample thickness of 10 mm.

18. Glass substrates for structural members of optical components, particularly in AR glasses, and especially as components of laminated substrates. - Wafers, particularly those having a maximum diameter of 5.0 cm to 50.0 cm, or a diameter of 0.7 cm to 50 cm, preferably 3 cm to 45 cm, or 5 cm to 40 cm. Lenses, especially spherical lenses, rod lenses, prisms or aspherical bodies, and / or Optical waveguides, especially fiber or plate A glass article comprising the optical glass described in any one of claims 1 to 17, in the form of the glass article.

19. Use of optical glass according to any one of claims 1 to 17 or glass article according to claim 18 in AR glasses, meta-optical components, wafer-level optical components, optical wafer applications, or conventional optical components, and / or as a wafer, lens, or optical waveguide.

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