High refractive index, high dispersion phosphate glass containing bismuth oxide

Abstract

The glass composition includes phosphorus oxide (P2O5), niobia (Nb2O5), titania (TiO2), and bismuth oxide (Bi2O3) as essential components, and may optionally include barium oxide (BaO), calcium oxide (CaO), potassium oxide (K2O), lithium oxide (Li2O), sodium oxide (Na2O), tungsten oxide (WO3), boron oxide (B2O3), and other components. The glass may be characterized by a relatively low density at room temperature and a high refractive index at 587.56 nm.

Description

Priority

[0001] This application claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 323,648, filed March 25, 2022, the contents of which are relied upon and incorporated herein by reference in their entirety. [Technical field]

[0002] The present disclosure relates generally to phosphate glasses having high refractive index and low density. The present disclosure also relates to glasses with high optical dispersion. [Background technology]

[0003] Glasses are used in a wide variety of optical devices, examples of which include augmented reality devices, virtual reality devices, mixed reality devices, and eyeglasses. Desirable properties of this type of glass include a high refractive index and low density. Additional desirable properties may include high transmission and / or low optical dispersion in the visible and near ultraviolet (near UV) range of the electromagnetic spectrum. Finding a glass that has the desired combination of these properties and can be formed from a composition that has good glass-forming ability can be a challenge. For example, generally speaking, as the refractive index of a glass increases, the density also tends to increase. Species such as TiO2 and Nb2O5 are often added to increase the refractive index of a glass without increasing the density of the glass. However, these materials often absorb blue and ultraviolet light, which can undesirably reduce the transmission of light in this region of the spectrum by the glass. Often, attempts to increase the refractive index of a glass without decreasing the transmission of the blue and ultraviolet regions of the spectrum while maintaining a low density can reduce the glass-forming ability of the material. For example, crystallization and / or liquid-liquid phase separation may occur during cooling of the glass melt at cooling rates generally accepted in the industry.Typically, as the amount of a particular species, such as ZrO2, Y2O3, Sc2O3, BeO, etc., increases, the glass-forming ability decreases.

[0004] Low density, high refractive index glasses mostly belong to one of two chemical families based on the glass formers used: (a) silicate or borosilicate glasses, in which SiO2 and / or B2O3 are used as the primary glass formers, and (b) phosphate glasses, in which P2O5 is used as the primary glass former. Glasses that rely on other oxides as the primary glass formers, such as GeO2, TeO2, Bi2O3, and / or V2O5, can be difficult to use due to cost, glass-forming ability, optical properties, and production requirements.

[0005] Phosphate glasses can be characterized by high refractive index and low density; however, phosphate glasses can be challenging to manufacture due to the risk of volatilization of P2O5 from the melt and platinum incompatibility. In addition, phosphate glasses are often highly colored and may require an extra bleaching step to provide a glass with the desired transmission characteristics. Furthermore, phosphate glasses that exhibit high refractive index also tend to exhibit increased optical dispersion, which may be exploited in certain applications. Summary of the Invention [Problem to be solved by the invention]

[0006] In light of these considerations, there is a need for phosphate glasses that have high refractive index and low density, optionally combined with high transmittance in the visible and near ultraviolet ranges, and / or are made from compositions that provide good glass forming capabilities. [Means for solving the problem]

[0007] According to an embodiment of the present disclosure, a glass includes a plurality of components, the glass including 15.9 mol% or more and 50.0 mol% or less of P2O5, 4.5 mol% or more and 50.0 mol% or less of Bi2O3, 0.0 mol% or more and 50.0 mol% or less of TiO2, 0.0 mol% or more and 50.0 mol% or less of Nb2O5, 0.0 mol% or more and 25.0 mol% or less of Li2O, 0.0 mol% or more and 25.0 mol% or less of K2O, 0.0 mol% or more and 20.0 mol% or less of Na2O, 0.0 mol% or more and 6 ... Li2O, 0.0 mol% or more and 25.0 mol% or less of K2O, 0.0 mol% or more and 20.0 The composition of the composition includes WO3, 0.0 mol% or more and 1.0 mol% or less of V2O5, the sum of TiO2+Nb2O5 is 25.0 mol% or more and 70.0 mol% or less, the sum of Alk2O is 0.5 mol% or more and 30.0 mol% or less, the sum of RO is 0.5 mol% or more and 30.0 mol% or less, the sum of GeO2+TeO2 is 0.0 mol% or more and 25.0 mol% or less, and may contain Al2O3 as necessary, and the composition of the composition is under the condition: Alk2O+RO+Bi2O3+3 * Al2O3-P2O5 [mol %]≧-8.0 is satisfied, in which Alk2O is the total of alkali metal oxides, and RO is the total of divalent metal oxides.

[0008] According to another embodiment of the present disclosure, a glass is provided that includes a plurality of components, the glass having a composition of components including 23.0 mol% or more and 35.0 mol% or less of P2O5, 4.5 mol% or more and 35.0 mol% or less of Bi2O3, 0.5 mol% or more and 55.0 mol% or less of Nb2O5, 0.5 mol% or more and 55.0 mol% or less of TiO2, 0.3 mol% or more and 20.0 mol% or less of Li2O, and optionally one or more components selected from BaO, KO, CaO, Na2O, SrO, WO3, BO3, SiO2, ZnO, ZrO2, MgO, Al2O3, TeO2, PbO, GeO2, Tl2O, Ag2O, CdO, Cs2O, Ga2O3, La2O3, MoO3, Ta2O5, and VO5, the glass being capable of being formed according to the condition: P n -(1.14+0.192 * P d )>0.000, where P n is represented by formula (I): TIFF2025509165000002.tif26160

[0009] The refractive index n at 587.56 nm, calculated from the glass composition in mole percent of the components d are parameters that predict P d is represented by formula (II): TIFF2025509165000003.tif31160

[0010] The density at room temperature, d, calculated from the glass composition in mole percent of the components RT is a parameter that predicts

[0011] These and other aspects, objects and features of the present disclosure will be understood and appreciated by those skilled in the art upon review of the following specification, claims, and accompanying drawings. [Brief description of the drawings]

[0012] [Figure 1] 1 is a plot showing the relationship between the refractive index nd and the refractive index parameter Pn calculated according to formula (I) for several comparative glasses and several exemplary glasses according to embodiments of the present disclosure. [Diagram 2] 1 is a plot showing the relationship between density dRT and density parameter Pd, calculated according to formula (II), for several comparative glasses and several exemplary glasses according to embodiments of the present disclosure. [Diagram 3] 13A-13C are plots of example cooling schedules for "15 minute test" and "2.5 minute test" conditions for several example glasses according to embodiments of the present disclosure. [Figure 4] 1 is a plot showing the relationship between the density parameter Pd and the refractive index parameter Pn for several comparative glasses and several example glasses according to embodiments of the present disclosure. [Diagram 5]1 is a plot showing the relationship between density at room temperature dRT and refractive index at 587.56 nm nd for several comparative glasses and several example glasses according to embodiments of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] In the following detailed description, for purposes of explanation and not limitation, example embodiments disclosing specific details are set forth in order to provide a thorough understanding of the various principles of the present disclosure. However, it will be apparent to one skilled in the art having the benefit of this disclosure that the present disclosure may be practiced in other embodiments that depart from the specific details disclosed herein. Moreover, descriptions of well-known devices, methods and materials may be omitted so as not to obscure the description of the various principles of the present disclosure. Finally, where applicable, like reference numerals refer to like elements.

[0014] Unless otherwise expressly stated, it is in no way intended that any method described herein be construed as requiring that its steps be performed in a particular order. Thus, if a method claim does not actually recite the order in which its steps must be followed, or unless otherwise specifically stated in the claim or description that the steps are to be limited to a particular order, no order is in any way intended to be implied. This applies to any possible non-expressive criteria of interpretation, including the sequence of steps or the flow of operations; the obvious meaning derived from grammatical construction or punctuation; or logical matters regarding the number or type of embodiments described in the specification.

[0015] As used herein, the term "and / or," when used with a list of two or more items, means that any one of the listed items can be used by itself, or any combination of two or more of the listed items can be used. For example, if a composition is described as containing components A, B, and / or C, the composition may contain only A, only B, only C, a combination of A and B, a combination of A and C, a combination of B and C, or a combination of A, B, and C.

[0016] Modifications of the present disclosure will occur to those skilled in the art who make or use the present disclosure. Accordingly, it is understood that the embodiments shown in the drawings and described above are for illustrative purposes only and are not intended to limit the scope of the present disclosure, the scope of which is defined by the following claims, as interpreted in accordance with the principles of patent law, including the doctrine of equivalents.

[0017] As used herein, the term "about" means that amounts, sizes, formulations, parameters, and other quantities and characteristics are not and need not be exact, but may be approximate and / or larger or smaller, as appropriate, to reflect tolerances, conversion factors, rounding, measurement errors, and the like, as well as other factors known to those of skill in the art. When the term "about" is used in describing a value or an endpoint of a range, the disclosure should be understood to include the specific value or endpoint referred to. Whether or not a numerical value or range endpoint is referred to in the specification as "about," the endpoint of the numerical value or range is intended to include both embodiments, those modified by "about" and those not modified by "about." It will be further understood that each endpoint of a range is significant both with respect to the other endpoint and independently of the other endpoint.

[0018] The term "ingredients" refers to materials or compounds included in the glass-forming batch composition. The ingredients include, but are not limited to, oxides including those represented in formulas (I), (II), and the claims. Representative ingredients include B2O3, P2O5, Al2O3, CuO, Cu2O, RO, R2O, SnO2, MnO2, RE, and the like. m O n, SiO2, Ta2O5, ZnO, WO3, Nb2O5, TiO2, ZrO2, Bi2O3, TeO2, etc. Other representative components include halogens (e.g., F, Br, Cl). Whenever a component is included as a term in a mathematical expression or formula, it is understood that the component refers to the amount of the component in mole % in the glass batch composition. For example, the formula "B2O3+P2O5" refers to the amount of B2O3 in mole % plus the amount of P2O5 in mole % in the glass batch composition. Mathematical expressions can include the "+", "-", " * It is any expression containing mathematical operators such as ",", " / ,", "min," or "max."

[0019] Unless otherwise specified, the amounts or contents of components in glass compositions are expressed herein in units of mol % (mole percent).

[0020] The term "formed from" can mean one or more of comprising, consisting essentially of, or consisting of. For example, a component formed from a particular material may comprise, consist essentially of, or consist of the particular material.

[0021] The terms "free" and "substantially free" are used interchangeably herein to refer to the amount and / or absence of a particular component in a glass composition that is not intentionally added to the glass composition. It is understood that the glass composition may contain trace amounts of a particular component as a contaminant or admixture in amounts less than 0.10 mole percent.

[0022] As used herein, the term "contaminants," when used to describe a particular component in a glass composition, refers to a component that is not intentionally added to the glass composition and is present in an amount less than 0.05 mole percent. A contaminant component may be unintentionally added to a glass composition as an impurity in another component and / or by migration of the contaminant component into the glass composition during processing of the composition.

[0023] Unless otherwise specified, the term "glass" is used to refer to glasses made from the glass compositions disclosed herein.

[0024] symbol" * " when used in any formula herein means multiplication.

[0025] Temperatures are expressed herein in °C (degrees Celsius).

[0026] Density is here expressed in g / cm 3 It is expressed in units of.

[0027] Viscosity is expressed herein in units of P (poise).

[0028] The term "glass former" is used herein to refer to a component that, when present alone in a glass composition (i.e., without other components, except as contaminants), is capable of forming a glass upon cooling of the melt at a rate of about 300° C. / min or less.

[0029] The term "modifier" as used herein refers to an oxide of a monovalent or divalent metal, i.e., R2O or RO, where "R" represents a cation. Modifiers can be added to glass compositions to change the atomic structure of the melt and the resulting glass. In some embodiments, modifiers can change the coordination number of the cations present in the glass formers (e.g., boron in B2O3), which results in a more polymerized atomic network, which in turn can better form a glass.

[0030] As used herein, the term "RO" refers to the total divalent metal oxide content, the term "RO" refers to the total monovalent metal oxide content, and the term "AlkO" refers to the total alkali metal oxide content. The term RO encompasses alkali metal oxides (AlkO) as well as other monovalent metal oxides such as AgO, TlO, and HgO. As previously noted, in this disclosure, rare earth metal oxides are referred to herein by the standard formula (REO) in which the rare earth metal has a redox state of "+3", and therefore rare earth metal oxides are not encompassed by the term RO.

[0031] As used herein, the term "rare earth metal" refers to the metals listed in the lanthanide series of the IUPAC periodic table, plus yttrium and scandium. As used herein, the term "rare earth metal oxide" is used to refer to oxides of rare earth metals in different redox states, such as lanthanum "+3" in La2O3, cerium "+4" in CeO2, and europium "+2" in EuO. In general, the redox state of the rare earth metal in an oxide glass can vary, and in particular, the redox state can change during melting based on the batch composition and / or the redox conditions in the furnace in which the glass is melted and / or heat treated (e.g., annealed). Unless otherwise indicated, rare earth metal oxides are referred to herein by standard formulas in which the rare earth metal has a redox state of "+3". Thus, if a rare earth metal having a redox state other than "+3" is added to a batch of a glass composition, the glass composition is recalculated by adding or removing some oxygen to maintain stoichiometry. For example, if CeO2 (cerium in a redox state of "+4") is used as a batch component, the resulting glass composition is recalculated assuming that 2 moles of CeO2 are equal to 1 mole of Ce2O3 and the resulting as-batched glass composition is expressed as Ce2O3. As used herein, "RE" refers to any combination of these terms. m O nThe term "RE2O3", also defined as "trivalent equivalent", is used to refer to the total content of rare earth metal oxides in all redox states present, and the term "RE2O3", also defined as "trivalent equivalent", is used to refer to the total content of rare earth metal oxides in the "+3" redox state.

[0032] Unless otherwise stated, all compositions are expressed in as-batched mole percent (mol%). As will be recognized by those skilled in the art, various melting components (e.g., fluorine, alkali metals, boron, etc.) may undergo different levels of volatilization (e.g., as a function of vapor pressure, melting time, and / or melting temperature) during melting of the component. Therefore, the term "about" with respect to such components is intended to encompass values ​​within about 0.2 mol% when measuring the final article compared to the as-batched composition provided herein. With the foregoing in mind, substantial compositional equivalence between the final article and the as-batched composition is expected.

[0033] The measured density of the glasses reported here is 0.001 g / cm 3 The Archimedes method is used in water with an error of g / cm 3 As used herein, density measurements at room temperature (d RT (identified as 0.01 g / cm3) are indicated as measured at 20° C. or 25° C. and include measurements taken at temperatures that may range from 20° C. to 25° C. Room temperature may vary from about 20° C. to about 25° C., but for purposes of this disclosure, the variation in density within the temperature range of 20° C. to 25° C. is in increments of 0.001 g / cm3. 3 It will be appreciated that the error is expected to be less than 10% and therefore is not expected to affect the room temperature density measurements reported herein.

[0034] As used herein, good glass-forming ability refers to the resistance of a melt to devitrification as the material cools. Glass-forming ability can be measured by determining the critical cooling rate of the melt. "Critical cooling rate" or "v crThe term "critical cooling rate" is used herein to refer to the minimum cooling rate at which a melt of a given composition forms a glass free of crystals visible under an optical microscope at 500x magnification. The critical cooling rate can be used to measure the glass-forming ability of a composition, i.e., the ability of a melt of a given glass composition to form a glass when cooled. Generally speaking, the lower the critical cooling rate, the better the glass-forming ability.

[0035] "Liquidus temperature" (T liq The term is used herein to refer to the temperature above which a glass composition is completely liquid, with no crystallization of the glass components. The liquidus temperature values ​​reported herein were obtained by measuring samples using DSC or isothermal holding of samples wrapped in platinum foil. For samples measured using DSC, powder samples were heated to 1250 °C at 10 K / min. The end of the endothermic event corresponding to the melting of the crystals was taken as the liquidus temperature. For the second technique (isostatic holding), a glass block (approximately 1 cm 2 ) was placed over the glass block to avoid volatilization. 3 The glass block was then wrapped in platinum foil and placed in a furnace at a given temperature for 17 hours. The glass block was then examined under an optical microscope to examine the crystals.

[0036] The refractive index values ​​reported herein were measured at room temperature unless otherwise stated. The refractive index values ​​of the glass samples were measured using a Metricon Model 2010 prism coupler refractometer with an error of approximately ±0.0002. Using the Metricon, the refractive index of the glass samples was measured at two or more wavelengths of approximately 406 nm, 473 nm, 532 nm, 633 nm, 828 nm, and 1064 nm. The measured dependences could be characterized as dispersions and then fitted with the Cauchy's Law equation or the Sellmeyer equation to calculate the refractive index of the sample at a given wavelength of interest between the measured wavelengths. "Refractive index n d The term "refractive index n" is used herein to refer to the refractive index calculated as above at a wavelength of 587.56 nm, which corresponds to the d-line wavelength of helium. cThe term "refractive index n" is used herein to refer to the refractive index calculated as above at a wavelength of 656.3 nm. F The term "refractive index n" is used herein to refer to the refractive index calculated as above at a wavelength of 486.1 nm. g The term "refractive index" is used herein to refer to the refractive index calculated as above at a wavelength of 435.8 nm.

[0037] As used herein, "high refractive index" refers to a refractive index value of the glass of at least 1.80 or greater, unless otherwise specified. When indicated, the term "high refractive index" refers to a refractive index value of the glass of at least 1.85 or greater, 1.90 or greater, or 1.95 or greater, or 2.00 or greater.

[0038] The terms "dispersion" and "optical dispersion" are used interchangeably herein to refer to the difference or ratio of the refractive indices of a glass sample at a given wavelength. One numerical measure of optical dispersion reported herein is the Abbe number, which is defined by the formula: x =(n x -1) / (n F -n C ), where "x" in this disclosure represents one of the commonly used wavelengths (e.g., 587.56 nm [d-line], 589.3 nm [D-line]), and n x is the refractive index at this wavelength, and n F and n C are the refractive indices at wavelengths of 486.1 nm (F line) and 656.3 nm (C line), respectively. d and v D The values ​​of ν vary very slightly, mostly by ±0.1% to ±0.2%. As reported here, the dispersion of the glass samples is related to the Abbe number (ν d ), which is represented by the following formula: d =(n d -1) / (n F -n c ) characterizes the relationship between the refractive indices of a sample at three different wavelengths, where n d is the calculated refractive index at 587.56 nm (d line), and n Fis the calculated refractive index at 486.1 nm, and n c is the calculated refractive index at 656.3 nm. A higher Abbe number corresponds to a lower optical dispersion.

[0039] The numerical value of the Abbe number corresponding to "high dispersion" or "low dispersion" will differ depending on the refractive index for which the Abbe number is calculated. In some cases, the Abbe number corresponding to "low dispersion" for a high refractive index glass may be lower than the Abbe number corresponding to "low dispersion" for a low refractive index glass. In other words, as the calculated refractive index value increases, the value of the Abbe number corresponding to low dispersion decreases. The same applies to "high dispersion" as well.

[0040] The glass transition temperature (Tg) is measured by differential scanning calorimetry (DSC) at a heating rate of 10 K / min after cooling in air.

[0041] The glass composition may include phosphorus oxide (P2O5). The glass composition in the embodiments described herein includes phosphorus oxide (P2O5) as a primary glass former. As the amount of P2O5 increases, the viscosity value at a given temperature increases, which prevents the melt from crystallizing as it cools, and thus improves the glass forming ability of the melt (i.e., lowers the critical cooling rate of the melt). However, P2O5 significantly reduces the refractive index. Therefore, the content of P2O5 in high refractive index glasses is limited. In embodiments, the glass composition includes phosphorus oxide (P2O5) in an amount of from greater than or equal to 15.9 mol % to less than or equal to 50.0 mol %, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain P2O5 in an amount of 15.9 mol% or more, 17.5 mol% or more, 18.0 mol% or more, 20.0 mol% or more, 23.0 mol% or more, 23.5 mol% or more, 24.05 mol% or more, 24.5 mol% or more, 35.0 mol% or more, 40.0 mol% or more, or 45.0 mol% or more. In some other embodiments, the glass composition may contain P2O5 in an amount of 50.0 mol% or less, 45.0 mol% or less, 40.0 mol% or less, 35.0 mol% or less, 28.0 mol% or less, 27.5 mol% or less, 25.5 mol% or less, 25.0 mol% or less, or 20.0 mol% or less. In further embodiments, the glass composition has a mol% or more of 15.9 mol% to 50.0 mol%, mol% or more of 17.5 mol% to 27.5 mol%, mol% or more of 18.0 mol% to 28.0 mol%, mol% or more of 23.0 mol% to 35.0 mol%, mol% or more of 23.5 mol% to 25.5 mol%, mol% or more of 24.05 mol% to 25.05 mol%, mol% or more of 24.2 mol% to 25.0 mol%, mol% or more of 24.48 mol% to 24.9 mol%, mol% or more of ... 9 mol% or less, 15.9 mol% or more and 20.0 mol% or less, 17.5 mol% or more and 50.0 mol% or less, 20.0 mol% or more and 25.0 mol% or less, 23.0 mol% or more and 50.0 mol% or less, 23.0 mol% or more and 25.0 mol% or less, 23.5 mol% or more and 50.0 mol% or less, 23.5 mol% or more and 25.0 mol% or less, or 24.05 mol% or more and 25.0 mol% or less.

[0042] The glass composition may include germania (GeO2). Germania (GeO2) provides a high ratio of refractive index to density and does not reduce visible transmittance. Germania is a glass-forming oxide. However, germania is expensive, and therefore the germania content should be limited or the glass composition may be free of GeO2. In embodiments, the glass composition may contain germania (GeO2) in an amount from greater than or equal to 0.0 mol% to less than or equal to 25.0 mol%, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain GeO2 in an amount of greater than or equal to 0.0 mol%, greater than or equal to 5.0 mol%, greater than or equal to 10.0 mol%, greater than or equal to 19.0 mol%, greater than or equal to 20.0 mol%, greater than or equal to 21.0 mol%, or greater than or equal to 23.0 mol%. In some other embodiments, the glass composition may contain GeO2 in an amount of 25.0 mol% or less, 23.0 mol% or less, 21.0 mol% or less, 20.0 mol% or less, 19.0 mol% or less, 10.0 mol% or less, or 5.0 mol% or less. In some further embodiments, the glass composition may contain GeO2 in an amount of 0.0 mol% to 5.0 mol%, 0.0 mol% to 25.0 mol%, 5.0 mol% to 25.0 mol%, 5.0 mol% to 10.0 mol%, 10.0 mol% to 25.0 mol%, 10.0 mol% to 19.0 mol%, 19.0 mol% to 25.0 mol%, 19.0 mol% to 20.0 mol%, 20.0 mol% to 25.0 mol%, or 20.0 mol% to 21.0 mol%.

[0043] The glass composition may include boron oxide (BO). According to some embodiments of the present disclosure, boron oxide may act as a glass former. As a glass former, BO may increase liquidus viscosity and therefore inhibit crystallization. However, the addition of BO to a glass composition may result in liquid-liquid phase separation, which may lead to devitrification and / or reduced visible transmittance of the resulting glass. Also, the addition of BO to a high refractive index glass may result in a reduced refractive index. Thus, the amount of boron oxide may be limited or the glass may be substantially free of BO. In embodiments, the glass composition may contain boron oxide (BO) in an amount from greater than or equal to 0.0 mol% to less than or equal to 10.0 mol%, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain BO in an amount greater than or equal to 0.0 mol%, or greater than or equal to 5.0 mol%. In some other embodiments, the glass composition may contain B2O3 in an amount of 10.0 mol% or less, 10.0 mol% or less, 8.0 mol% or less, or 5.0 mol% or less. In still some embodiments, the glass composition may contain B2O3 in an amount of 0.0 mol% to 15.0 mol%, 0.0 mol% to 8.0 mol%, 0.0 mol% to 5.0 mol%, 5.0 mol% to 15.0 mol%, or 5.0 mol% to 8.0 mol%.

[0044] The glass composition may include an alkali metal oxide (Alk2O). The alkali metal oxides (Li2O, Na2O, K2O, Rb2O, and Cs2O) may help incorporate high refractive index components, such as TiO2, Nb2O5, or WO3, into the glass structure at a given density. Typically, Li2O, Na2O, and / or K2O are used for this purpose. Of these three oxides, K2O typically has the greatest effect on the solubility of the high refractive index components; however, adding K2O by itself may lower the refractive index. Li2O typically provides the highest ratio of refractive index to density among the alkali metal oxides, but has the lowest effect on the solubility of the high refractive index components. Sodium oxide (Na2O) typically provides an intermediate effect between Li2O and K2O. However, the exact effect of these oxides on glass forming ability is difficult to predict, and the desired ratio between these oxides will be different in different embodiments. Specifically, in some other embodiments, it may be desirable to add all of these oxides (Li2O, Na2O, and KO) or two of them together with each other. Also, in some embodiments, the use of monovalent metal oxides (RO) along with divalent metal oxides (RO) may improve the glass forming ability of the glass and allow for a higher refractive index at a given density. Thus, in some embodiments of the present disclosure, the total alkali metal oxide content may be limited.

[0045] In some embodiments, the glass composition may contain the alkali metal oxide AlkO in an amount of 0.5 mol% or more, 10.0 mol% or more, or 20.0 mol% or more. In some other embodiments, the glass composition may contain the alkali metal oxide AlkO in an amount of 30.0 mol% or less, 20.0 mol% or less, or 10.0 mol% or less. In still some embodiments, the glass composition may contain the alkali metal oxide AlkO in an amount of 0.5 mol% or more and 30.0 mol% or less, 0.5 mol% or more and 20.0 mol% or less, 0.5 mol% or more and 10.0 mol% or more, 10.0 mol% or more and 30.0 mol% or less, or 10.0 mol% or more and 20.0 mol% or less.

[0046] The glass composition may include potassium oxide (K2O). Potassium oxide may increase the solubility of high refractive index components such as TiO2 and Nb2O5 to a greater extent than other monovalent and divalent metal oxides. However, potassium oxide itself provides the lowest refractive index among the alkali metal oxides. Thus, at high concentrations of K2O, it may be difficult to reach a high refractive index. Thus, the amount of K2O in the glasses of the present disclosure may be limited, or the glasses may be substantially free of K2O. In embodiments, the glass composition may contain potassium oxide (K2O) in an amount from greater than or equal to 0.0 mol% to less than or equal to 25.0 mol%, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain K2O in an amount of greater than or equal to 0.0 mol%, greater than or equal to 2.0 mol%, greater than or equal to 5.0 mol%, greater than or equal to 10.0 mol%, greater than or equal to 19.0 mol%, greater than or equal to 20.0 mol%, greater than or equal to 21.0 mol%, or greater than or equal to 23.0 mol%. In some other embodiments, the glass composition may contain KO in an amount of 25.0 mol% or less, 23.0 mol% or less, 21.0 mol% or less, 20.0 mol% or less, 19.0 mol% or less, 10.0 mol% or less, 8.0 mol% or less, 7.5 mol% or less, or 5.0 mol% or less. In still some embodiments, the glass composition may contain KO in an amount of 0.0 mol% to 25.0 mol%, 0.0 mol% to 10.0 mol%, 0.0 mol% to 7.5 mol%, 2.06 mol% to 7.5 mol%, 5.0 mol% to 7.5 mol%, 10.0 mol% to 19.0 mol%, or 19.0 mol% to 20.0 mol%.

[0047] The glass composition may include lithium oxide (Li2O). Lithium oxide provides the highest ratio of refractive index to density of glasses among known monovalent metal oxides. Also, in some embodiments, Li2O may help increase the solubility of Nb2O5 and TiO2, which further increases the refractive index at a given density. In addition, lithium oxide may accelerate the process of bleaching the glass. However, even at sufficiently low concentrations, the addition of Li2O may reduce the glass-forming ability of the glass and may result in crystallization or liquid-liquid phase separation of the glass-forming melt upon cooling. Thus, the amount of Li2O is limited. In some embodiments, the glass may be substantially free of Li2O. In embodiments, the glass composition may contain lithium oxide (Li2O) in an amount from greater than or equal to 0.0 mol % to less than or equal to 25.0 mol %, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain LiO in an amount of 0.0 mol% or more, 0.1 mol% or more, 0.3 mol% or more, 5.0 mol% or more, 10.0 mol% or more, 19.0 mol% or more, 20.0 mol% or more, 21.0 mol% or more, or 23.0 mol% or more. In some other embodiments, the glass composition may contain LiO in an amount of 25.0 mol% or less, 23.0 mol% or less, 21.0 mol% or less, 20.0 mol% or less, 19.0 mol% or less, 10.0 mol% or less, 7.5 mol% or less, 6.5 mol% or less, 5.75 mol% or less, 5.0 mol% or less, or 2.1 mol% or less.Further, in some embodiments, the glass composition may contain LiO in an amount of from 0.0 mol % to 25.0 mol %, from 0.0 mol % to 10.0 mol %, from 0.0 mol % to 7.5 mol %, from 0.0 mol % to 6.5 mol %, from 0.0 mol % to 5.75 mol %, from 0.3 mol % to 20.0 mol %, from 0.42 mol % to 2.08 mol %, from 0.0 mol % to 2.1 mol %, from 0.1 mol % to 2.1 mol %, from 0.3 mol % to 2.1 mol %, from 5.0 mol % to 25.0 mol %, from 5.0 mol % to 5.75 mol %, from 10.0 mol % to 19.0 mol %, or from 19.0 mol % to 20.0 mol %.

[0048] The glass composition may include sodium oxide (Na2O). In high refractive index glasses, Na2O functions like K2O to improve the solubility of high refractive index components such as TiO2, Nb2O5, and WO3, while at the same time, Na2O itself functions to lower the refractive index of the glass. In most cases, the effect of Na2O on the solubility of high refractive index components has been found to be slightly lower than the corresponding effect of K2O. However, Na2O provides a lower coefficient of thermal expansion than K2O, which may reduce the thermal stresses that arise when the glass article is cooled, and therefore improve the quality of the article. In embodiments, the glass composition may contain sodium oxide (Na2O) in an amount from 0.0 mol% or more to 20.0 mol% or less, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain Na2O in an amount of 0.0 mol% or more, 5.0 mol% or more, 10.0 mol% or more, 14.0 mol% or more, 16.0 mol% or more, or 18.0 mol% or more. In some other embodiments, the glass composition may contain NaO in an amount of 20.0 mol% or less, 18.0 mol% or less, 16.0 mol% or less, 14.0 mol% or less, 10.0 mol% or less, 7.5 mol% or less, 6.5 mol% or less, 5.75 mol% or less, or 5.0 mol% or less. In still some embodiments, the glass composition may contain NaO in an amount of 0.0 mol% or more and 20.0 mol% or less, 0.0 mol% or more and 10.0 mol% or more, 0.0 mol% or more and 7.5 mol% or less, 0.0 mol% or more and 6.5 mol% or less, 0.0 mol% or more and 5.75 mol% or less, 0.03 mol% or more and 4.97 mol% or more, or 0.0 mol% or more and 5.0 mol% or less.

[0049] The glass composition may include divalent metal oxides (RO). Divalent metal oxides such as alkaline earth metal oxides (BeO, MgO, CaO, SrO, and BaO), zinc oxide (ZnO), cadmium oxide (CdO), lead oxide (PbO), etc., when present in the glass, provide a higher refractive index than most monovalent oxides. Some divalent metal oxides, such as CaO, SrO, and ZnO, also provide a relatively low density, thus increasing the ratio of refractive index to density and therefore improving the performance of the optical glass. In addition, divalent metal oxides may help increase the solubility of high refractive index components such as TiO2, Nb2O5, and WO3, which further increases the refractive index at a given density. However, when added in large amounts, divalent metal oxides may result in crystallization of refractory minerals from the melt or liquid-liquid phase separation, which may reduce the glass-forming ability of the glass. Therefore, the amount of divalent metal oxides in the glass composition of the present disclosure is limited.

[0050] In some embodiments, the glass composition may contain divalent metal oxide RO in an amount of 0.3 mol% or more, 0.5 mol% or more, 10.0 mol% or more, or 20.0 mol% or more. In some other embodiments, the glass composition may contain divalent metal oxide RO in an amount of 30.0 mol% or less, 20.0 mol% or less, or 10.0 mol% or less. In still some embodiments, the glass composition may contain RO in an amount of 0.3 mol% to 20.0 mol%, 0.5 mol% to 30.0 mol%, 0.3 mol% to 30.0 mol%, or 0.3 mol% to 10.0 mol%, 0.5 mol% to 20.0 mol%, or 0.5 mol% to 10.0 mol%, 10.0 mol% to 30.0 mol%, or 10.0 mol% to 20.0 mol%.

[0051] The glass composition may include barium oxide (BaO). Barium oxide may increase the solubility of high refractive index components such as TiO2 and Nb2O5, thereby increasing the refractive index at a given density. However, barium is a heavy element and will increase the density of the glass when added in large amounts. Also, at high concentrations, barium may lead to crystallization of minerals such as barium titanate (BaTiO3), barium niobate (BaNb2O6), and barium orthophosphate (Ba3P2O8). Thus, the amount of BaO in the glass may be limited or the glass may be substantially free of BaO. In embodiments, the glass composition may contain sodium oxide (BaO) in an amount from greater than or equal to 0.0 mol% to less than or equal to 20.0 mol%, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain BaO in an amount of greater than or equal to 0.0 mol%, greater than or equal to 1.75 mol%, greater than or equal to 3.0 mol%, or greater than or equal to 10.0 mol%. In some other embodiments, the glass composition may contain BaO in an amount of 20.0 mol% or less, 10.0 mol% or less, 9.0 mol% or less, or 8.0 mol% or less. In still some embodiments, the glass composition may contain BaO in an amount of 0.0 mol% to 20.0 mol%, 0.0 mol% to 10.0 mol%, 0.0 mol% to 9.0 mol%, 1.75 mol% to 8.0 mol%, 2.59 mol% to 8.99 mol%, 0.0 mol% to 8.0 mol%, 1.75 mol% to 20.0 mol%, 3.0 mol% to 20.0 mol%, or 3.0 mol% to 8.0 mol%.

[0052] The glass composition may include calcium oxide (CaO). Calcium oxide provides the highest ratio of refractive index to density among known monovalent and divalent metal oxides. In some embodiments, CaO may also help increase the solubility of Nb2O5 and TiO2, which further increases the refractive index at a given density. However, too much CaO in the glass may lead to crystallization of refractory species such as calcium titanate (CaTiO3, CaTi2O5, etc.), calcium niobate (CaNb2O6), calcium metasilicate (CaSiO3), etc. This effect may reduce the viscosity at the liquidus temperature and thus increase the critical cooling rate, which may lead to crystallization of the melt upon cooling. Therefore, the amount of CaO is limited. In embodiments, the glass composition may contain calcium oxide (CaO) in an amount from greater than or equal to 0.0 mol % to less than or equal to 17.0 mol %, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain CaO in an amount of 0.0 mol% or more, 1.0 mol% or more, or 10.0 mol% or more. In some other embodiments, the glass composition may contain CaO in an amount of 17.0 mol% or less, 10.0 mol% or less, or 9.0 mol% or less. In still some embodiments, the glass composition may contain CaO in an amount of 0.0 mol% or more and 10.0 mol% or less, 0.0 mol% or more and 9.0 mol% or less, 0.97 mol% or more and 8.99 mol% or more, 0.0 mol% or more and 17.0 mol% or less, 1.0 mol% or more and 17.0 mol% or less, or 1.0 mol% or more and 9.0 mol% or less.

[0053] The glass composition may include vanadia (VO). Vanadia provides the highest ratio of refractive index to density of all oxides. However, vanadia may result in undesirable dark or even black coloration and may also raise environmental concerns. For these reasons, the vanadia content in the glass may be limited or the glass composition may be free of VO. In embodiments, the glass composition may contain vanadia (VO) in an amount from greater than or equal to 0.0 mol% to less than or equal to 5.0 mol%, and all ranges and subranges therebetween. In some other embodiments, the glass composition may contain VO in an amount less than or equal to 5.0 mol%, less than or equal to 2.5 mol%, or less than or equal to 1.0 mol%. In still other embodiments, the glass composition may contain VO in an amount less than or equal to 0.0 mol% and less than or equal to 1.0 mol%, or less than or equal to 0.0 mol% and less than or equal to 5.0 mol%.

[0054] The glass composition may include tungsten oxide (WO3). WO3 provides a high refractive index without significantly increasing density or undesirable coloration. However, high WO3 content tends to increase the liquidus temperature and decrease the viscosity at the liquidus temperature, making it difficult to avoid crystallization of the melt upon cooling. Therefore, the tungsten oxide content should be limited or the glass composition may be free of WO3. In embodiments, the glass composition may contain tungsten oxide (WO3) in an amount from greater than or equal to 0.0 mol% to less than or equal to 10.0 mol%, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain WO3 in an amount of greater than or equal to 0.0 mol%, greater than or equal to 3.93 mol%, greater than or equal to 5.0 mol%, greater than or equal to 7.0 mol%, greater than or equal to 8.0 mol%, or greater than or equal to 9.0 mol%. In some other embodiments, the glass composition may contain WO3 in an amount of 10.0 mol% or less, 9.0 mol% or less, 8.0 mol% or less, 7.5 mol% or less, 7.0 mol% or less, 6.5 mol% or less, 6.0 mol% or less, 5.0 mol% or less, or 4.8 mol% or less. In some further embodiments, the glass composition may contain WO3 in an amount of 0.0 mol% to 10.0 mol%, 0.0 mol% to 7.5 mol%, 0.0 mol% to 6.5 mol%, 0.0 mol% to 6.0 mol%, 3.93 mol% to 4.8 mol%, 0.0 mol% to 4.8 mol%, 5.0 mol% to 6.0 mol%, or 8.0 mol% to 9.0 mol%.

[0055] The glass composition may include bismuth oxide (Bi2O3). Bi2O3 provides a very high refractive index, but also results in an increase in density. However, bismuth oxide may also reduce the viscosity of the melt at high temperatures, which may result in crystallization of the melt upon cooling. This effect is particularly pronounced at high Bi2O3 contents. Therefore, the bismuth oxide content should be limited. In embodiments, the glass composition may contain bismuth oxide (Bi2O3) in an amount from greater than or equal to 4.0 mol% to less than or equal to 50.0 mol%, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain Bi2O3 in an amount of greater than or equal to 4.0 mol%, greater than or equal to 4.5 mol%, greater than or equal to 5.0 mol%, greater than or equal to 10.0 mol%, greater than or equal to 25.0 mol%, greater than or equal to 35.0 mol%, greater than or equal to 40.0 mol%, or greater than or equal to 45.0 mol%. In some other embodiments, the glass composition may contain Bi2O3 in an amount of 50.0 mol% or less, 45.0 mol% or less, 40.0 mol% or less, 35.0 mol% or less, 30.0 mol% or less, 25.0 mol% or less, 23.0 mol% or less, or 10.0 mol% or less. Further, in some embodiments, the glass composition may contain Bi2O3 in an amount of ≧4.0 mol% to ≦30.0 mol%, ≧4.5 mol% to ≦50.0 mol%, ≧4.5 mol% to ≦35.0 mol%, ≧5.0 mol% to ≦30.0 mol%, ≧5.0 mol% to ≦25.0 mol%, ≧5.0 mol% to ≦23.0 mol%, ≧4.0 mol% to ≦50.0 mol%, ≧4.5 mol% to ≦10.0 mol%, ≧10.0 mol% to ≦50.0 mol%, ≧10.0 mol% to ≦23.0 mol%, ≧25.0 mol% to ≦50.0 mol%, and ≧25.0 mol% to ≦30.0 mol%.

[0056] The glass composition may include titania (TiO2). High index glasses typically include species such as TiO2 and Nb2O5 that absorb at least a portion of the visible light, particularly wavelengths in the blue and near ultraviolet ranges. In embodiments of the present disclosure, the transmittance of the glass may be characterized for different wavelengths in the range of about 300 nm to 2300 nm. High transmittance in the visible and near ultraviolet ranges (blue range) is particularly desirable in certain applications. High transmittance in the blue range can be a challenge to achieve with high index glasses. High levels of TiO2 and / or Nb2O5, commonly used in glasses to increase the refractive index, tend to reduce transmittance in the near ultraviolet range and shift the UV cutoff to higher wavelengths. Thus, the amount of TiO2 may be limited or the glass composition may be substantially free of TiO2. In embodiments, the glass composition may contain titania (TiO2) in an amount of from greater than or equal to 0.0 mol% to less than or equal to 55.0 mol%, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain TiO2 in an amount of 0.0 mol% or more, 0.3 mol% or more, 0.5 mol% or more, 7.0 mol% or more, 10.0 mol% or more, 13.0 mol% or more, 14.0 mol% or more, 25.0 mol% or more, 40.0 mol% or more, 45.0 mol% or more, or 50.0 mol% or more. In some other embodiments, the glass composition may contain TiO2 in an amount of 55.0 mol% or less, 50.0 mol% or less, 45.0 mol% or less, 40.0 mol% or less, 36.0 mol% or less, 33.0 mol% or less, 30.0 mol% or less, 25.0 mol% or less, or 10.0 mol% or less.In further embodiments, the glass composition has a composition of 0.0 mol % to 50.0 mol %, 0.3 mol % to 40.0 mol %, 0.5 mol % to 55.0 mol %, 7.0 mol % to 40.0 mol %, 10.0 mol % to 36.0 mol %, 13.0 mol % to 33.0 mol %, 13.7 mol % to 30.23 mol %, 0.0 mol % to 55.0 mol %, 0.5 ... mol% or less, 0.0 mol% or more and 10.0 mol% or less, 0.3 mol% or more and 10.0 mol% or less, 0.5 mol% or more and 10.0 mol% or less, 7.0 mol% or more and 55.0 mol% or less, 7.0 mol% or more and 10.0 mol% or less, 10.0 mol% or more and 25.0 mol% or less, 13.0 mol% or more and 25.0 mol% or less, or 14.0 mol% or more and 25.0 mol% or less.

[0057] The glass composition may include niobia (Nb2O5). Like titania, niobia can be used to increase the refractive index of the glass while maintaining a low density. However, niobia can introduce a yellow coloration to the glass that cannot be decolorized in the same manner as titania, which can impair transmission, especially in the blue and ultraviolet ranges. Like titania, niobia can lead to crystallization and / or phase separation of the melt. In some embodiments, the glass may be substantially free of Nb2O5. In embodiments, the glass composition may contain niobia (Nb2O5) in an amount from greater than or equal to 0.0 mol% to less than or equal to 55.0 mol%, and all ranges and subranges therebetween. In some embodiments, the glass composition may contain Nb2O5 in an amount of 0.0 mol% or more, 0.5 mol% or more, 7.0 mol% or more, 10.0 mol% or more, 14.0 mol% or more, 16.5 mol% or more, 19.0 mol% or more, 25.0 mol% or more, 40.0 mol% or more, 45.0 mol% or more, or 50.0 mol% or more. In some other embodiments, the glass composition may contain Nb2O5 in an amount of 55.0 mol% or less, 50.0 mol% or less, 45.0 mol% or less, 40.0 mol% or less, 33.0 mol% or less, 30.5 mol% or less, 29.0 mol% or less, 25.0 mol% or less, or 10.0 mol% or less. In further embodiments, the glass composition has a composition selected from the group consisting of 0.0 mol % to 50.0 mol %, 0.5 mol % to 55.0 mol %, 7.0 mol % to 40.0 mol %, 10.0 mol % to 40.0 mol %, 14.0 mol % to 33.0 mol %, 16.5 mol % to 30.5 mol %, 18.83 mol % to 28.82 mol %, 0.0 mol % to 55.0 mol %, 0.5 ... mol% or less, 0.0 mol% or more and 10.0 mol% or less, 0.5 mol% or more and 10.0 mol% or less, 7.0 mol% or more and 55.0 mol% or less, 7.0 mol% or more and 10.0 mol% or less, 14.0 mol% or more and 55.0 mol% or less, 14.0 mol% or more and 25.0 mol% or less, 16.5 mol% or more and 25.0 mol% or less, or 19.0 mol% or more and 25.0 mol% or less.

[0058] In some embodiments, the glass composition may have a sum of GeO2+TeO2 of 0.0 mol% or more, 10.0 mol% or more, or 20.0 mol% or more. In some other embodiments, the glass composition may have a sum of GeO2+TeO2 of 25.0 mol% or less, 20.0 mol% or less, or 10.0 mol% or less. In some further embodiments, the glass composition may have a sum of GeO2+TeO2 of 0.0 mol% or more and 25.0 mol% or less, 0.0 mol% or more and 20.0 mol% or less, 0.0 mol% or more and 10.0 mol% or more, 10.0 mol% or more and 25.0 mol% or less, or 10.0 mol% or more and 20.0 mol% or less.

[0059] In some embodiments, the glass composition may have a sum of Na2O+K2O of 0.0 mol % or more, or 0.3 mol % or more.

[0060] In some embodiments, the glass composition may have a sum of P2O5+B2O3 of 0.0 or 20.0 mol% or more. In some other embodiments, the glass composition may have a sum of P2O5+B2O3 of 35.0 mol% or less, or 20.0 mol% or less. In still some embodiments, the glass composition may have a sum of P2O5+B2O3 of 20.0 mol% or more and 35.0 mol% or less, 0.0 mol% or more and 35.0 mol% or less, or 0.0 mol% or more and 20.0 mol% or less.

[0061] In some embodiments, the glass composition may have a sum of TiO2 + Nb2O5 of 0.0 mol% or more, 25.0 mol% or more, 36.0 mol% or more, or 50.0 mol% or more. In some other embodiments, the glass composition may have a sum of TiO2 + Nb2O5 of 70.0 mol% or less, 58.0 mol% or less, or 50.0 mol% or less. Further, in some embodiments, the glass composition may have a sum of TiO2 + Nb2O5 of 25.0 mol% or more and 70.0 mol% or less, 0.0 mol% or more and 70.0 mol% or less, 0.0 mol% or more and 58.0 mol% or less, or 0.0 mol% or more and 50.0 mol% or less, 25.0 mol% or more and 58.0 mol% or less, or 25.0 mol% or more and 50.0 mol% or less, 36.0 mol% or more and 70.0 mol% or less, 36.0 mol% or more and 58.0 mol% or less, or 36.0 mol% or more and 50.0 mol% or less.

[0062] In some embodiments, the glass composition has a difference of Alk2O+RO+Bi2O3+3 * There may be a limit of Al2O3-P2O5. The difference (Alk2O+RO+Bi2O3+3 * If the difference (Al2O3-P2O5) is zero or positive, i.e. the total content of Alk2O, RO, Bi2O3 in the glass and three times the content of Al2O3 is equal to or greater than the content of P2O5, it is possible to melt glass from solid materials such as metaphosphates (KPO3, NaPO3, BaP2O6, BiPO4, AlP3O9, etc.), which simplifies the melting process and reduces costs. * When the difference (Al2O3-P2O5) is negative, it is typically necessary to use a liquid starting material such as phosphoric acid (H3PO4) (which makes the process more complicated and more expensive) or to use a more expensive solid material such as titanium phosphate (TiP2O7) (which also increases the cost of the starting material). Therefore, the difference (Alk2O+RO+Bi2O3+3 *It is preferred that the difference Al2O3-P2O5) is positive or zero. In some embodiments, the glass has a difference Alk2O+RO+Bi2O3+3 * Al2O3-P2O5 may be -8 mol% or more, 0.000 mol% or more, or 10 mol% or more. In some other embodiments, the glass has a difference of Alk2O+RO+Bi2O3+3 * Al2O3-P2O5 may be 11 mol% or less, 10 mol% or less, or 0.000 mol% or less. In some embodiments, the glass has a difference of Alk2O+RO+Bi2O3+3 * Al2O3-P2O5 may be -8 mol% or more and 11 mol% or less, -8 mol% or more and 10 mol% or less, or -8 mol% or more and 0.000 mol% or less, 0.000 mol% or more and 11 mol% or less, or 0.000 mol% or more and 10 mol% or less.

[0063] In some embodiments, the glass has a refractive index at 587.56 nm, n, of 1.8 or more, or 1.9 or more, or 2.0 or more. d It may have.

[0064] In some embodiments, the glass has an Abbe number ν of 20.0 or less, or 19.5 or less, or 19.0 or less, or 18.5 or less. d It may have.

[0065] In some embodiments, the glasses may have a glass transition temperature Tg of from 550° C. or more to 650° C. or less, and all ranges and subranges therebetween. In some embodiments, the glasses may have a glass transition temperature Tg of 550° C. or more, 560° C. or more, 590° C. or more, 620° C. or more, 630° C. or more, or 640° C. or more. In some other embodiments, the glasses may have a glass transition temperature Tg of 650° C. or less, 640° C. or less, 630° C. or less, 620° C. or less, 590° C. or less, or 560° C. or less. Further, in some embodiments, the glass may have a glass transition temperature, Tg, of 550°C or more and 650°C or less, 550°C or more and 560°C or less, 560°C or more and 650°C or less, 560°C or more and 590°C or less, 590°C or more and 650°C or less, 590°C or more and 620°C or more and 620°C or more and 650°C or less, 620°C or more and 630°C or more and 630°C or more and 650°C or less, or 630°C or more and 640°C or more.

[0066] In some embodiments, the glass has a refractive index to density ratio ("refraction") (n d -1) / d RT It may have.

[0067] In some embodiments, the glass has a viscosity of 5.5 g / cm 3 or less than 5.2g / cm 3 or less than 5.0g / cm 3 or less than 4.8g / cm 3 or less than 4.6g / cm 3 Below, 4.4g / cm 3 or less than 4.2g / cm 3 The density at room temperature is d RT It may have.

[0068] In some embodiments, the glass has a quantity n greater than or equal to 0.000. d -(1.14+0.192 * d RT) may be present.

[0069] In some embodiments, the glass has a quantity n greater than or equal to 0.000. d -(1.205+0.192 * d RT ) may be present.

[0070] Refractive index n d and density d RT is a glass property that can be predicted from the glass composition. Linear regression analysis of the exemplary glasses of this disclosure in the Examples section below and other glass compositions reported in the literature was performed to determine the refractive index, n d and density d RT We have determined an equation that can predict the composition dependence of .

[0071] Meets the compositional limits set forth in Table 1 below and has the properties of interest (n d and d RT Glass compositions having measured values ​​of each property (n d and d RT A training data set of about 100 glass compositions for each glass composition was randomly selected from the literature data presented in the public SciGlass Information System database and example glasses from the embodiments presented herein. Linear regression analysis on the data sets defined above, excluding outliers, was used to determine the mean glass composition for each glass composition, n d and d RT A prediction parameter P n and P d The formulas (I) and (II) presented in Table 2 below were determined for the glass compositions that met the compositional limits of Table 1. A separate subset of glass compositions that met the compositional limits of Table 1 was used as a validation set to evaluate the ability to complement within the compositional limits of Table 1, and the predicted parameter P n and P d An external data set of prior art glass compositions, also randomly selected from the SciGlass Information System database, was used to establish the standard deviations specified in Table 2 for properties (n dand d RT The ability to predict each property (n d and d RT Multiple iterations of this process were performed to determine the best equation for predicting .Equations (I) and (II) in Table 2 are the results of this analysis.

[0072] Data for the comparative glass compositions used in the linear regression analysis, including the training data set, validation data set, and external data set, were obtained from the publicly available SciGlass Information System database. Equations (I) and (II) below are used in the linear regression analysis: TIFF2025509165000004.tif26160

[0073] TIFF2025509165000005.tif31160

[0074] Obtained from.

[0075] In formulas (I) and (II) and Tables 1 and 2, P n is the refractive index n at 587.56 nm d is a prediction parameter that predicts the glass composition, calculated from the components of the glass composition expressed in mole percent, and p d is the density at room temperature d RT is a prediction parameter that predicts the glass composition's compositional composition (mol%).

[0076] In formulas (I) and (II), each component of the glass composition is listed in terms of its chemical formula, where the chemical formula refers to the concentration of the component expressed in mole percent. For example, for purposes of formulas (I) and (II), P2O5 refers to the concentration of P2O5 expressed in mole percent in the glass composition. It will be understood that not all components listed in formulas (I) and (II) are necessarily present in a particular glass composition, and that formulas (I) and (II) are equally valid for glass compositions containing less than all of the components listed in the formulas. It will be further understood that formulas (I) and (II) are also valid for glass compositions falling within the scope and claims of the present disclosure that contain components in addition to those listed in the formulas. If a component listed in formulas (I) and (II) is not present in a particular glass composition, the concentration of that component in that glass composition is 0 mole percent, and the contribution of that component to the value calculated from the formulas is zero. In Table 1, R m O n is the sum of all oxides.

[0077] [Table 1]

[0078] [Table 2]

[0079] FIG. 1 shows the measured refractive index n for several comparative glasses ("Comparative Glasses") and several exemplary glasses ("Exemplary Glasses") selected from the literature. d Parameter P calculated by formula (I) as a function of n As shown in the data in Figure 1, the parameter P n The composition dependence of n for most glasses is d The standard deviations were within ±0.015 units of 0.015 units, which corresponds to the standard deviations specified in Table 2.

[0080] FIG. 2 shows the measured density d for several comparative glasses ("Comparative Glasses") and several exemplary glasses ("Exemplary Glasses"). RT Parameter P calculated by formula (II) as a function of d As shown in the data in Figure 2, the parameter P d The composition dependence of is measured for most glasses. RT The standard deviations were within ±0.075 units of 0.015 μm, which corresponds to the standard deviations specified in Table 2.

[0081] Table 3 identifies combinations of components and their respective amounts according to some embodiments of the present disclosure. Exemplary Glass A in Table 3 may include additional components according to any aspect of the present disclosure described herein.

[0082] [Table 3]

[0083] Exemplary glass A according to an embodiment of the present disclosure meets the following criteria: Alk2O+RO+Bi2O3+3 * Al2O3-P2O5[mol%]≧-8.0 where the formula refers to the amount of the component in the glass expressed in mole percent.

[0084] Table 4 identifies combinations of components and their respective amounts according to some embodiments of the present disclosure. Exemplary Glass B in Table 4 may include additional components according to any aspect of the present disclosure described herein.

[0085] [Table 4]

[0086] Exemplary glass B according to an embodiment of the present disclosure meets the following criteria: n d -(1.14+0.192 * d RT )>0.000 In the formula, n d is the refractive index at 587.56 nm, and d RT is the density at room temperature.

[0087] According to some embodiments of the present disclosure, exemplary glass B meets the following criteria: n d -(1.205+0.192 * d RT )>0.000 In the formula, n d is the refractive index at 587.56 nm, and d RT is the density at room temperature. EXAMPLES

[0088] The following examples illustrate various features and advantages provided by the present disclosure and are not intended to limit the scope of the invention and the appended claims in any way.

[0089] To prepare glass samples of some exemplary glasses of the present disclosure, about 15 grams of each sample (with target species content of >99.99 wt%) was melted from batch raw materials at a temperature of about 1300°C in platinum or platinum-rhodium crucibles (Pt:Rh=80:20) for 1 hour. One of two controlled cooling conditions was applied. In the first cooling condition (referred to as the "15 min test"), it takes about 15 minutes for the sample to cool from 1100°C to 500°C in the furnace. In the second cooling condition (referred to as the "2.5 min test"), it takes about 2.5 minutes for the sample to cool from 1100°C to 500°C. Temperature readings were taken by directly reading the furnace temperature or by using an IR camera reading with a conversion table. The first condition (15 min test) corresponds approximately to a temperature of 1000° C. and a cooling rate of 300° C. / min, and the second corresponds approximately to a cooling rate of 600° C. / min at 1000° C. The temperature of 1000° C. corresponds approximately to the temperature at which the cooling rate is expected to reach its maximum value. At lower temperatures, the cooling rate is also significantly reduced. A typical schedule of the first and second cooling schemes is shown in FIG. 3. For these samples, observations are specified in Table 5, called "15 min devitrification test" and "2.5 min devitrification test"; an observation "1" is used to indicate that the glass composition passed the corresponding test (a composition is considered to have passed the indicated devitrification test if the melt of the composition formed a glass containing no crystals visible under an optical microscope at a magnification of 100× to 500×). An observation "0" is used to indicate that the glass composition failed the indicated devitrification test.

[0090] To prepare other glass samples of the exemplary glasses of the present disclosure, one kilogram batches were prepared in pure platinum crucibles unless otherwise noted. The crucibles were placed in a furnace set at a temperature of 1250° C., and the furnace temperature was then increased to 1300° C. and held at 1300° C. for two hours. The furnace temperature was then reduced to 1250° C. and the glass was allowed to equilibrate at this temperature for one hour, after which it was poured onto a steel table and slowly cooled at about Tg for one hour.

[0091] Some sample melts were also melted in a Joule-heated "1 liter" platinum crucible. Approximately 3700 g of raw materials (batched ingredients) were used during this process. The crucible was filled with the batch ingredients at 1250°C for 1.5 hours. The temperature was then increased to 1300°C and held for 1 hour. The glass was continuously stirred at 60 rpm during this process. The temperature was then decreased to 1200°C where it was equilibrated for 30 minutes and stirring was continued at a speed of 20 rpm. The feed tube was heated to 1225°C and the glass melt was poured onto a chilled graphite table to form the glass. The glass was formed into bars approximately 25 mm thick, 50 mm wide and 90 cm long. The bars were examined under an optical microscope to check for crystallization. All the bars were free of crystals. The glass quality, as observed by optical microscopy, was good with no striae or bubbles in the bars. For rough annealing, the glass was placed in an annealing furnace at about Tg for 1 hour. The bars were then annealed in a static furnace at about Tg for 1 hour, and then the temperature was reduced at 1°C / min.

[0092] No chemical analysis of the test samples was performed since chemical analyses were performed on similar samples prepared in independent melts by XRF (X-ray Fluorescence - for all oxides except B2O3 and Li2O), ICP (Inductively Coupled Plasma Mass Spectroscopy - for B2O3), and FES (Flame Emission Spectroscopy - for Li2O). These analyses yielded deviations from the batched composition within ±2.0% by weight for the major components.

[0093] Exemplary glass compositions are listed in Table 5. Comparative glass compositions are listed in Table 6. In Tables 5 and 6, the abbreviation "n" with a subscript refers to the refractive index at the corresponding wavelength in nm; e.g., n 632.8nm refers to the refractive index at a wavelength of 632.8 nm.

[0094] [Table 5-1]

[0095] [Table 5-2]

[0096] [Table 5-3]

[0097] [Table 5-4]

[0098] [Table 5-5]

[0099] [Table 5-6]

[0100] [Table 5-7]

[0101] [Table 5-8]

[0102] [Table 5-9]

[0103] [Table 5-10]

[0104] Table 6 below lists the glass compositions and properties for comparative glasses C1-C12.

[0105] [Table 6-1]

[0106] [Table 6-2]

[0107] The references for each of the comparative glasses listed in Table 6 are as follows: [1] China Patent Publication No. 113024107A; [2] JP 2004-123448A; [3] JP 2006-111499A; [4] JP 2010-083701; [5] U.S. Patent Publication No. 2021 / 179479; [6] U.S. Patent No. 8647994 B2;[7] U.S. Patent No. 8716157 B2;[8] WO 2019 / 151404 A1;[9] U.S. Patent Application Publication No. 2021 / 048665;

[10] U.S. Patent No. 7309670 B2;

[11] U.S. Patent No. 7553785 B2;

[12] U.S. Patent No. 7994082 B2.

[0108] FIG. 4 shows the density parameter P for some of the example glasses and some of the comparative glasses. d and the refractive index parameter P n 1 is a plot showing the relationship between refractive index at 587.56 nm, n. The exemplary glasses (closed circles) are Examples 13 to 21, 34 to 49, 51 to 57, and 75 from Table 5. The comparative glasses (open circles) are Examples C1 to C8 from Table 6. d The refractive index parameter P that predicts n was determined according to formula (I). The density at room temperature d RT The density parameter P that predicts d was determined according to formula (II). All of the exemplary and comparative glasses shown in FIG.

[0109] [Table 7]

[0110] Among the known glasses having the characteristics specified in Table 7, the parameter P d Over the range of values ​​of the parameter P n The comparative glass was selected as having the highest value of

[0111] The equation shown in Figure 4 is y=1.14+0.192 * The lines corresponding to x provide a visual indication of the difference between the comparative glasses having the characteristics set forth in Table 7 and the exemplary glasses 13 to 21, 34 to 49, 51 to 57, and 75. As can be seen from FIG. 4, the exemplary glasses (black circles) listed above have a parameter P n where x is the parameter P that predicts the density at room temperature. d Corresponding to the line y=1.14+0.192 * x and not above any of the comparative glasses (open circles) shown in Figure 4. In other words, some of the exemplary glasses shown in Figure 4 have the following formula (III)(a): P n -(1.14+0.192 * P d )>0.00 (III)(a) and none of the comparative glasses shown in FIG. 4 satisfy this formula.

[0112] As can also be seen from FIG. 4, some of the example glasses shown in FIG. 4 have a parameter P that predicts the refractive index at 587.56 nm when y is 587.56 nm. n where x is the parameter P that predicts the density at room temperature. d Corresponding to the line y=1.18+0.192 * x above which none of the comparative glasses shown in Figure 4 are above. In other words, some of the exemplary glasses shown in Figure 4 have the following formula (III)(b): P n -(1.18+0.192 * P d )>0.00 (III)(b) and none of the comparative glasses shown in FIG. 4 satisfy this formula.

[0113] The examples shown in FIG. 4 show, by prediction, a d RT and d is superior (i.e., for a given n d Regarding lower d RT , or a given d RT Regarding higher n d ).

[0114] FIG. 5 shows the room temperature density d for some of the example glasses and some of the comparative glasses. RT and the refractive index n at 587.56 nm d 5 is a plot showing the relationship between. The exemplary glasses (closed circles) are Examples 17, 34 through 43, 46 through 48, and 51 through 57 from Table 5. The comparative glasses (open circles) are Examples C2, C4, C5, C7, and C9 through C12 from Table 6. All of the exemplary and comparative glasses shown in FIG. 5 have the characteristics defined in Table 7.

[0115] Among the known glasses having the above characteristics specified in Table 7, the density at room temperature d RT The refractive index at 587.56 nm, n d The comparative glass shown in FIG. 5 was selected as having the highest measured value of .

[0116] The equation shown in Figure 5 is y=1.140+0.192 * The lines corresponding to x provide a visual indication of the difference between the comparative glasses having the characteristics set forth in Table 7 and the exemplary glasses 17, 34 to 43, 46 to 48, and 51 to 57. As can be seen from FIG. 5, the exemplary glasses (black circles) described above have a y of n d corresponds to x, and d RT Corresponding to the line y=1.140+0.192 * x and not above any of the comparative glasses (open circles) shown in Figure 5. In other words, some of the exemplary glasses shown in Figure 5 have the following formula (IV)(a): n d -(1.140+0.192 * dRT )>0.00 (IV)(a) and none of the comparative glasses shown in FIG. 5 satisfy this formula.

[0117] As can also be seen from FIG. 5, some of the exemplary glasses shown in FIG. 5 have a y of n d corresponds to x, and d RT Corresponding to the line y=1.18+0.192 * x above which none of the comparative glasses shown in Figure 5 are above. In other words, some of the exemplary glasses shown in Figure 5 have the following formula (IV)(b): n d -(1.18+0.192 * d RT )>0.00 (IV)(b) and none of the comparative glasses shown in FIG. 5 satisfy this formula.

[0118] The examples shown in FIG. 5 that satisfy formula (IV)(b) are among the glasses having the characteristics specified in Table 7, including: RT At similar values ​​of n d It is characterized by the highest value of

[0119] This means that under the conditions specified in Table 7 above, some of the example glasses have a density d at room temperature that is lower than the best of the comparative glasses that meet the same conditions. RT The refractive index n at 587.56 nm is measured at a similar level d This means that the measurements show that these exemplary glasses have high d RT At similar values ​​of n d i.e., they have higher values ​​of d RT and d is superior (i.e., for a given n d Regarding lower d RT , or a given d RT Regarding higher n d ) can be interpreted as

[0120] Values ​​of all attributes defined in Table 7 and formulas (III)(a), (III)(b), (IV)(a) and (IV)(b) for comparative glasses C1 through C12 plotted in Figures 4 and 5 are presented below in Table 8. All compositions of the comparative glasses are presented in Table 6. All compositions and attributes of the exemplary glasses are presented in Table 5.

[0121] [Table 8-1]

[0122] [Table 8-2]

[0123] As can be seen from Figures 4 and 5, both predicted and measured data of properties show that some of the exemplary glasses have refractive indices n at 587.56 nm that are better than the best of the comparative glasses having the characteristics specified in Table 7. d and density at room temperature d RT It is confirmed that the combination of

[0124] The following non-limiting embodiments are encompassed by the present disclosure: To the extent not already described, any one of the features of the first through thirty-fifth embodiments may be combined, in part or in whole, with one or more features of any other embodiment of the present disclosure to form additional embodiments, even if the combination is not expressly described.

[0125] According to a first aspect, the glass includes a plurality of components, the glass including 15.9 mol% or more and 50.0 mol% or less of P2O5, 4.5 mol% or more and 50.0 mol% or less of Bi2O3, 0.0 mol% or more and 50.0 mol% or less of TiO2, 0.0 mol% or more and 50.0 mol% or less of Nb2O5, 0.0 mol% or more and 25.0 mol% or less of Li2O, 0.0 mol% or more and 25.0 mol% or less of K2O, 0.0 mol% or more and 20.0 mol% or less of Na2O, 0.0 mol% or more and 6.0 mol% or less of SiO2, and 0.0 mol% or more and 6.0 mol% or less of SiO2. The composition of the composition includes WO3 below, 0.0 mol% or more and 1.0 mol% or less of V2O5, the sum of TiO2+Nb2O5 is 25.0 mol% or more and 70.0 mol% or less, the sum of Alk2O is 0.5 mol% or more and 30.0 mol% or less, the sum of RO is 0.5 mol% or more and 30.0 mol% or less, the sum of GeO2+TeO2 is 0.0 mol% or more and 25.0 mol% or less, and may contain Al2O3 as necessary, and the composition of this component is under the condition: Alk2O+RO+Bi2O3+3 * Al2O3-P2O5 [mol %]≧-8.0 is satisfied, in which Alk2O is the total of alkali metal oxides, and RO is the total of divalent metal oxides.

[0126] According to a second aspect, the glass is provided in accordance with the following condition: P d < 4.8 and P n >2.0, where p n is the refractive index n at 587.56 nm d The formula (I): TIFF2025509165000025.tif26160

[0127] is a parameter calculated from the glass composition in mole percent of the components according to d is the density at room temperature d RT , which predicts the formula (II): TIFF2025509165000026.tif31160

[0128] The glass of the first embodiment, wherein the parameter is calculated from the glass composition in terms of mole percent of the components according to the formula:

[0129] According to a third embodiment, the glass has a density of 4.8 g / cm 3 The density at room temperature, d RT , and a refractive index at 587.56 nm of 2.0 or more d The glass of any one of embodiments 1 to 2, having the following structure:

[0130] According to a fourth aspect, the glass has an Abbe number ν d The glass of any one of embodiments 1 to 3, having the following structure:

[0131] According to the fifth aspect, the Abbe number v d The glass of the fourth embodiment, wherein the refractive index is 18.5 or less.

[0132] According to a sixth aspect, the glass of any one of aspects 1 to 5, wherein the glass has a glass transition temperature Tg of 550°C or higher and 650°C or lower.

[0133] According to a seventh aspect, the glass of any one of aspects 1-6, wherein the glass does not crystallize when cooled in air from 1100° C. to 500° C. in 15 minutes.

[0134] According to an eighth aspect, the glass of any one of aspects 1-7, wherein the composition of components includes 23.5 to 25.5 mol% P2O5, 10.0 to 40.0 mol% Nb2O5, 4.5 to 30.0 mol% Bi2O3, 0.3 to 40.0 mol% TiO2, 0.0 to 15.0 mol% B2O3, 0.0 to 10.0 mol% BaO, 0.0 to 10.0 mol% CaO, 0.0 to 10.0 mol% K2O, 0.0 to 10.0 mol% Li2O, and 0.0 to 10.0 mol% Na2O.

[0135] According to a ninth aspect, the glass of any one of aspects 1-8, wherein the composition of components includes one or more of the following components: 24.05 to 25.05 mol% P2O5, 14.0 to 33.0 mol% Nb2O5, 10.0 to 36.0 mol% TiO2, 5.0 to 25.0 mol% Bi2O3, 0.0 to 9.0 mol% BaO, 0.0 to 9.0 mol% CaO, 0.0 to 7.5 mol% K2O, 0.0 to 6.5 mol% Li2O, and 0.0 to 6.5 mol% Na2O.

[0136] According to a tenth aspect, the glass of any one of aspects 1-9, wherein the composition of components includes 24.2 to 25.0 mol% P2O5, 16.5 to 30.5 mol% Nb2O5, 13.0 to 33.0 mol% TiO2, 5.0 to 23.0 mol% Bi2O3, 1.75 to 8.00 mol% BaO, 0.0 to 9.0 mol% CaO, 0.0 to 7.5 mol% K2O, 0 to 5.75 mol% Li2O, and 0 to 5.75 mol% Na2O.

[0137] According to an eleventh aspect, the composition of the components is: Alk2O+RO+Bi2O3+3 * The glass of any one of aspects 1 to 10, wherein Al2O3-P2O5 [mol %] ≧0.000.

[0138] According to a twelfth aspect, the glass of any one of aspects 1 to 7 and 11, wherein the composition of components includes 18.0 mol% or more and 28.0 mol% or less of P2O5, 0.0 mol% or more and 10.0 mol% or less of TeO2, 0.0 mol% or more and 5.0 mol% or less of GeO2, and 0.0 mol% or more and 5.0 mol% or less of SiO2, and the total of P2O5+B2O3 is 20.0 mol% or more and 35.0 mol% or less.

[0139] According to a thirteenth aspect, the glass of any one of aspects 1 to 12, wherein the composition of components contains 0.1 mol % or more of Li2O and the total of Na2O+K2O is 0.3 mol % or more.

[0140] According to a fourteenth aspect, the glass of any one of aspects 1 to 13, wherein the composition of components comprises 0.3 mol% or more and 20.0 mol% or less of RO, and 0.3 mol% or more and 20.0 mol% or less of RO, where RO is the sum of monovalent metal oxides.

[0141] According to a fifteenth aspect, there is provided a method for producing an optical element, comprising the step of processing the glass according to any one of the first to fourteenth aspects.

[0142] According to a sixteenth aspect, an optical element made from the glass of any one of aspects 1 to 14.

[0143] According to a seventeenth aspect, a glass is provided that includes a plurality of components, the glass having a composition of components including 23.0 to 35.0 mol% P2O5, 4.5 to 35.0 mol% Bi2O3, 0.5 to 55.0 mol% Nb2O5, 0.5 to 55.0 mol% TiO2, 0.3 to 20.0 mol% Li2O, and optionally one or more components selected from BaO, KO, CaO, Na2O, SrO, WO3, BO, SiO2, ZnO, ZrO2, MgO, Al2O3, TeO2, PbO, GeO2, Tl2O, Ag2O, CdO, Cs2O, Ga2O3, La2O3, MoO3, Ta2O5, and V2O5, the glass being characterized in that the glass satisfies the condition: P n -(1.14+0.192 * P d )>0.000, where P n is represented by formula (I): TIFF2025509165000027.tif26160

[0144] The refractive index n at 587.56 nm, calculated from the glass composition in mole percent of the components dare parameters that predict P d is represented by formula (II): TIFF2025509165000028.tif31160

[0145] The density at room temperature, d, calculated from the glass composition in mole percent of the components RT is a parameter that predicts

[0146] According to an eighteenth embodiment, the glass is characterized in that: d -(1.14+0.192 * d RT )>0.000, where n d is the refractive index at 587.56 nm, and d RT [g / cm 3 ] is the density at room temperature.

[0147] According to a nineteenth embodiment, the glass is characterized in that: d -(1.205+0.192 * d RT )>0.000, where n d is the refractive index at 587.56 nm, and d RT [g / cm 3 19. The glass of any one of embodiments 17-18, wherein:

[0148] According to a twentieth aspect, the glass is characterized in that the glass satisfies the condition: P n -(1.205+0.192 * P d 20. The glass of any one of embodiments 17 to 19, wherein the glass satisfies a viscosity index (SAR) of 0.000.

[0149] According to a twenty-first embodiment, the glass is characterized in that the glass satisfies the condition: P d < 4.8 and P n The glass of any one of embodiments 17 to 20, wherein the glass satisfies >2.0.

[0150] According to a twenty-second embodiment, the glass has a viscosity of 4.8 g / cm 3 The density at room temperature, d RT, and a refractive index at 587.56 nm of 2.0 or more d 22. The glass of any one of embodiments 17 to 21, having the following structure:

[0151] According to a twenty-third embodiment, the glass has an Abbe number ν d 23. The glass of any one of embodiments 17 to 22, having the following structure:

[0152] According to the twenty-fourth aspect, the Abbe number v d The glass of the twenty-third embodiment, wherein the refractive index is 18.5 or less.

[0153] According to a twenty-fifth aspect, the glass of any one of aspects 17 to 24, wherein the glass has a glass transition temperature Tg of 550° C. or higher and 650° C. or lower.

[0154] According to a twenty-sixth aspect, the glass of any one of aspects 17 to 25, wherein the glass does not crystallize when cooled in air from 1100° C. to 500° C. in 15 minutes.

[0155] According to a twenty-seventh aspect, the glass of any one of aspects 17 to 26, wherein the composition of components includes 23.5 to 25.5 mol% P2O5, 10.0 to 40.0 mol% Nb2O5, 4.5 to 30.0 mol% Bi2O3, 0.5 to 40.0 mol% TiO2, 0.3 to 10.0 mol% Li2O, 0.0 to 15.0 mol% B2O3, 0.0 to 10.0 mol% BaO, 0.0 to 10.0 mol% CaO, 0.0 to 10.0 mol% K2O, 0.0 to 10.0 mol% Na2O, and 0.0 to 10.0 mol% WO3.

[0156] According to a twenty-eighth aspect, the glass of any one of aspects 17-27, wherein the composition of components includes one or more of the following components: 24.05 to 25.05 mol% P2O5, 14.0 to 33.0 mol% Nb2O5, 10.0 to 36.0 mol% TiO2, 5.0 to 25.0 mol% Bi2O3, 0.3 to 6.5 mol% Li2O, 0.0 to 9.0 mol% BaO, 0.0 to 9.0 mol% CaO, 0.0 to 7.5 mol% K2O, 0.0 to 6.5 mol% Na2O, and 0.0 to 6.5 mol% WO3.

[0157] According to a twenty-ninth aspect, the glass of any one of aspects 17 to 28, wherein the composition of components includes 24.2 to 25.0 mol% P2O5, 16.5 to 30.5 mol% Nb2O5, 13.0 to 33.0 mol% TiO2, 5.0 to 23.0 mol% Bi2O3, 1.75 to 8.00 mol% BaO, 0.3 to 5.8 mol% Li2O, 0.0 to 9.0 mol% CaO, 0.0 to 7.5 mol% K2O, 0.0 to 6.0 mol% WO3, and 0 to 5.75 mol% Na2O.

[0158] According to a thirtieth embodiment, the composition of the components is: Alk2O+RO+Bi2O3+3 * The glass of any one of aspects 17 to 29, wherein Al2O3-P2O5 [mol %]≧0.000 is satisfied, Alk2O is the sum of alkali metal oxides, and RO is the sum of divalent metal oxides.

[0159] According to a 31st aspect, the glass of any one of aspects 17 to 26 and 30, wherein the composition of components includes 23.0 mol% or more and 28.0 mol% or less of P2O5, 0.0 mol% or more and 10.0 mol% or less of TeO2, 0.0 mol% or more and 5.0 mol% or less of GeO2, and 0.0 mol% or more and 5.0 mol% or less of SiO2, and the total of P2O5+B2O3 is 20.0 mol% or more and 35.0 mol% or less.

[0160] According to a thirty-second aspect, the glass of any one of aspects 17 to 31, wherein the total of Na2O+K2O in the component composition is 0.3 mol % or more.

[0161] According to a thirty-third aspect, the glass of any one of aspects 17 to 32, wherein the composition of components comprises 0.3 mol% or more and 20.0 mol% or less of RO, and 0.3 mol% or more and 20.0 mol% or less of RO, where RO is the sum of monovalent metal oxides and RO is the sum of divalent metal oxides.

[0162] According to a thirty-fourth aspect, there is provided a method for producing an optical element, comprising the step of processing the glass according to any one of aspects seventeen to thirty-three.

[0163] According to a thirty-fifth aspect, an optical element made from the glass of any one of aspects seventeen to thirty-three.

[0164] Many variations and modifications may be made to the above-described embodiments of the present disclosure without departing substantially from the spirit and various principles of the present disclosure, and all such variations and modifications are intended to be included herein within the scope of this disclosure and protected by the following claims.

[0165] To the extent not already described, different features of the various aspects of the disclosure may be used in combination with one another as desired. The fact that a particular feature is not explicitly shown or described with respect to each aspect of the disclosure is not intended to be construed as impossible, but is done for brevity and clarity of description. Thus, various features of different aspects may be combined and adapted as necessary to form new aspects, whether or not the new aspects are explicitly disclosed.

[0166] Preferred embodiments of the present invention will be described below in detail.

[0167] EMBODIMENT 1 In a glass containing multiple components, the glass may include 15.9 mol% or more and 50.0 mol% or less P2O5, 4.5 mol% or more and 50.0 mol% or less of Bi2O3; 0.0 mol% or more and 50.0 mol% or less of TiO2; 0.0 mol% or more and 50.0 mol% or less of Nb2O5; 0.0 mol% or more and 25.0 mol% or less of Li2O, 0.0 mol% or more and 25.0 mol% or less of K2O, Na2O, 0.0 mol% or more and 6.0 mol% or less of WO3, 0.0 mol% or more and 1.0 mol% or less of V2O5, Including, The sum of TiO2+Nb2O5 is 25.0 mol% or more and 70.0 mol% or less, the sum of AlkO is 0.5 mol % or more and 30.0 mol % or less; The total of RO is 0.5 mol% or more and 30.0 mol% or less, The sum of GeO2+TeO2 is 0.0 mol% or more and 25.0 mol% or less, Optionally containing Al2O3, The composition of the components is The composition of the components is as follows: Alk2O+RO+Bi2O3+3 * Al2O3-P2O5[mol%]≧-8.0 wherein AlkO is the sum of alkali metal oxides and RO is the sum of divalent metal oxides.

[0168] EMBODIMENT 2 The glass has the following characteristics: P d < 4.8, and P n >2.0, In the formula: p n is the refractive index n at 587.56 nm d The formula (I): TIFF2025509165000029.tif26160

[0169] is a parameter calculated from the glass composition in mole percent of the components according to P d is the density at room temperature d RT , which predicts the formula (II): TIFF2025509165000030.tif31160

[0170] 2. The glass of embodiment 1, wherein the parameters are calculated from the glass composition in terms of mole percent of the components according to

[0171] EMBODIMENT 3 The glass, Abbe number ν less than 20 d , 3. The glass of claim 1 or 2, having

[0172] EMBODIMENT 4 4. The glass of any one of claims 1 to 3, wherein the glass does not crystallize when cooled in air from 1100°C to 500°C in 15 minutes.

[0173] EMBODIMENT 5 The composition of the components is 23.5 mol% or more and 25.5 mol% or less P2O5, 10.0 mol% or more and 40.0 mol% or less of Nb2O5; 4.5 mol% or more and 30.0 mol% or less of Bi2O3; 0.3 mol% or more and 40.0 mol% or less of TiO2; 0.0 mol% or more and 15.0 mol% or less of B2O3; 0.0 mol% or more and 10.0 mol% or less of BaO; 0.0 mol% or more and 10.0 mol% or less of CaO; 0.0 mol% or more and 10.0 mol% or less of K2O, 0.0 mol % or more and 10.0 mol % or less of Li2O, and 0.0 mol% or more and 10.0 mol% or less of Na2O, 5. The glass of any one of the preceding claims, comprising:

[0174] EMBODIMENT 6 The composition of the components is 24.2 mol% or more and 25.0 mol% or less P2O5, 16.5 mol% or more and 30.5 mol% or less of Nb2O5; 13.0 mol% or more and 33.0 mol% or less of TiO2; 5.0 mol% or more and 23.0 mol% or less of Bi2O3; 1.75 mol% or more and 8.00 mol% or less of BaO; 0.0 mol% or more and 9.0 mol% or less of CaO; 0.0 mol% or more and 7.5 mol% or less of K2O, 0 mol % or more and 5.75 mol % or less of Li2O, and 0 mol% or more and 5.75 mol% or less of Na2O, 6. The glass of any one of the preceding claims, comprising:

[0175] EMBODIMENT 7 The composition of the components is such that: Alk2O+RO+Bi2O3+3 * Al2O3-P2O5[mol%]≧0.000 7. The glass of any one of the preceding claims, wherein

[0176] EMBODIMENT 8 The composition of the components is 0.1 mol % or more of LiO, Including, 8. The glass of any one of the preceding claims, wherein the sum of Na2O+K2O is 0.3 mol % or greater.

[0177] EMBODIMENT 9 A method for producing an optical element, comprising processing a glass according to any one of embodiments 1 to 8.

[0178] EMBODIMENT 10 An optical element made from a glass according to any one of the preceding embodiments.

[0179] EMBODIMENT 11 In a glass containing multiple components, the glass may include 23.0 mol% or more and 35.0 mol% or less P2O5, 4.5 mol% or more and 35.0 mol% or less of Bi2O3; 0.5 mol% or more and 55.0 mol% or less of Nb2O5; 0.5 mol% or more and 55.0 mol% or less of TiO2; 0.3 mol% or more and 20.0 mol% or less of Li2O, Including, Optionally containing one or more components selected from BaO, K2O, CaO, Na2O, SrO, WO3, B2O3, SiO2, ZnO, ZrO2, MgO, Al2O3, TeO2, PbO, GeO2, Tl2O, Ag2O, CdO, Cs2O, Ga2O3, La2O3, MoO3, Ta2O5, and V2O5; The composition of the components is The glass is in accordance with the following conditions: P n -(1.14+0.192 * P d )>0.000 In the formula: P n is represented by formula (I): TIFF2025509165000031.tif26160

[0180] The refractive index n at 587.56 nm, calculated from the glass composition in mole percent of the components d are parameters that predict P d is represented by formula (II): TIFF2025509165000032.tif31160

[0181] The density at room temperature, d, calculated from the glass composition in mole percent of the components RT is a parameter that predicts glass.

[0182] EMBODIMENT 12 The glass has the following characteristics: n d -(1.14+0.192 * d RT )>0.000 In the formula: n d is the refractive index at 587.56 nm, d RT [g / cm 3 12. The glass of embodiment 11, wherein:

[0183] EMBODIMENT 13 The glass, Abbe number ν less than 20 d 13. The glass of embodiment 11 or 12, having

[0184] EMBODIMENT 14 14. The glass of any one of claims 11 to 13, wherein the glass does not crystallize when cooled in air from 1100°C to 500°C in 15 minutes.

[0185] EMBODIMENT 15 The composition of the components is 23.5 mol% or more and 25.5 mol% or less P2O5, 10.0 mol% or more and 40.0 mol% or less of Nb2O5; 4.5 mol% or more and 30.0 mol% or less of Bi2O3; 0.5 mol% or more and 40.0 mol% or less of TiO2; 0.3 mol% or more and 10.0 mol% or less of Li2O, 0.0 mol% or more and 15.0 mol% or less of B2O3; 0.0 mol% or more and 10.0 mol% or less of BaO; 0.0 mol% or more and 10.0 mol% or less of CaO; 0.0 mol% or more and 10.0 mol% or less of K2O, 0.0 mol% or more and 10.0 mol% or less of Na2O, and 0.0 mol% or more and 10.0 mol% or less of WO3, 15. The glass of any one of claims 11 to 14, comprising:

[0186] EMBODIMENT 16 The composition of the components is 24.2 mol% or more and 25.0 mol% or less P2O5, 16.5 mol% or more and 30.5 mol% or less of Nb2O5; 13.0 mol% or more and 33.0 mol% or less of TiO2; 5.0 mol% or more and 23.0 mol% or less of Bi2O3; 1.75 mol% or more and 8.00 mol% or less of BaO; 0.3 mol% or more and 5.8 mol% or less of Li2O; 0.0 mol% or more and 9.0 mol% or less of CaO; 0.0 mol% or more and 7.5 mol% or less of K2O, 0.0 mol% or more and 6.0 mol% or less of WO3, and 0 mol% or more and 5.75 mol% or less of Na2O, 16. The glass of any one of claims 11 to 15, comprising:

[0187] EMBODIMENT 17 The composition of the components is such that: Alk2O+RO+Bi2O3+3 * Al2O3-P2O5[mol%]≧0.000 Fulfilling 17. The glass according to any one of claims 11 to 16, wherein the formula refers to the content of the corresponding component in the glass, AlkO being the sum of alkali metal oxides and RO being the sum of divalent metal oxides.

[0188] EMBODIMENT 18 18. The glass of any one of claims 11 to 17, wherein the sum of Na2O+K2O in said composition is 0.3 mol% or more.

[0189] EMBODIMENT 19 The composition of the components is 0.3 mol % or more and 20.0 mol % or less of R2O, and 0.3 mol% or more and 20.0 mol% or less of RO; Including, 19. The glass of any one of embodiments 11 to 18, wherein R2O is the sum of monovalent metal oxides and RO is the sum of divalent metal oxides.

[0190] EMBODIMENT 20 A method for producing an optical element, comprising processing a glass according to any one of embodiments 11 to 19.

[0191] EMBODIMENT 21 20. An optical element made from a glass according to any one of embodiments 11 to 19.

Claims

1. In a glass containing multiple components, the glass may include 15.9 mol% or more and 50.0 mol% or less P ２ O ５ , 4.5 mol% or more and 50.0 mol% or less of Bi ２ O ３ , 0.0 mol% or more and 50.0 mol% or less of TiO ２ , 0.0 mol% or more and 50.0 mol% or less of Nb ２ O ５ , Li of 0.0 mol% or more and 25.0 mol% or less ２ O. 0.0 mol% or more and 25.0 mol% or less of K ２ O. 0.0 mol% or more and 20.0 mol% or less of Na ２ O. 0.0 mol% or more and 6.0 mol% or less WO ３ , 0.0 mol % or more and 1.0 mol % or less V ２ O ５ , Including, TiO ２ +Nb ２ O ５ The sum of these is 25.0 mol % or more and 70.0 mol % or less, Alk ２ The total amount of O is 0.5 mol % or more and 30.0 mol % or less, The total of RO is 0.5 mol % or more and 30.0 mol % or less, GeO ２ + TeO ２ The total of is 0.0 mol % or more and 25.0 mol % or less, A ２ O ３ Including, as appropriate, The composition of the components is The composition of the components is as follows: Alk ２ O+RO+Bi ２ O ３ +3 ＊ Al ２ O ３ -P ２ O ５ [モル%]≧-8.0 In the formula, ２ Glasses in which O is the sum of alkali metal oxides and RO is the sum of divalent metal oxides.

2. The glass has the following properties: P ｄ < 4.8, and P ｎ >2.0、 In the formula: p ｎ is the refractive index n at 587.56 nm ｄ and predicting the formula (I): is a parameter calculated from the glass composition in mole percent of the components according to P ｄ is the density at room temperature d ＲＴ , which predicts the formula (II):

2. The glass of claim 1, wherein the parameter is calculated from the glass composition in terms of mole percent of the components according to

3. The composition of the components is 23.5 mol% or more and 25.5 mol% or less P ２ O ５ , 10.0 mol% or more and 40.0 mol% or less of Nb ２ O ５ , 4.5 mol% or more and 30.0 mol% or less of Bi ２ O ３ , 0.3 mol% or more and 40.0 mol% or less of TiO ２ , 0.0 mol% or more and 15.0 mol% or less B ２ O ３ , BaO: 0.0 mol% or more and 10.0 mol% or less; 0.0 mol% or more and 10.0 mol% or less of CaO; K of 0.0 mol% or more and 10.0 mol% or less ２ O. Li of 0.0 mol% or more and 10.0 mol% or less ２ O, and 0.0 mol% or more and 10.0 mol% or less of Na ２ O. The glass of claim 1 or 2, comprising:

4. The composition of the components is 24.2 mol% or more and 25.0 mol% or less P ２ O ５ , 16.5 mol% or more and 30.5 mol% or less of Nb ２ O ５ , 13.0 mol% or more and 33.0 mol% or less of TiO ２ , Bi: 5.0 mol% or more and 23.0 mol% or less ２ O ３ , BaO of 1.75 mol% or more and 8.00 mol% or less, 0.0 mol% or more and 9.0 mol% or less of CaO; 0.0 mol% or more and 7.5 mol% or less of K ２ O. Lithium of 0 mol% or more and 5.75 mol% or less ２ O, and 0 mol% or more and 5.75 mol% or less of Na ２ O. The glass of claim 1 or 2, comprising:

5. The composition of the components is such that: Alk ２ O+RO+Bi ２ O ３ +3 ＊ Al ２ O ３ -P ２ O ５ [モル%]≧0.000 The glass according to claim 1 or 2, which satisfies the above.

6. The composition of the components is 0.1 mol% or more of Li ２ O. Including, Na ２ O+K ２ 3. The glass according to claim 1, wherein the total amount of O is 0.3 mol % or more.

7. In a glass containing multiple components, the glass may include 23.0 mol% or more and 35.0 mol% or less P ２ O ５ , 4.5 mol% or more and 35.0 mol% or less of Bi ２ O ３ , 0.5 mol% or more and 55.0 mol% or less of Nb ２ O ５ , 0.5 mol% or more and 55.0 mol% or less of TiO ２ , 0.3 mol% or more and 20.0 mol% or less of Li ２ O. Including, BaO,K. ２ O, CaO, Na ２ O, SrO, WO ３ , B ２ O ３ , SiO ２ , ZnO, ZrO ２ , MgO, Al ２ O ３ , TeO ２ , PbO, GeO ２ , Tl ２ O, Ag ２ O, CdO, Cs ２ O, Ga ２ O ３ , La ２ O ３ , MoO ３ , Ta ２ O ５ , and V ２ O ５ Optionally, one or more components selected from The composition of the components is The glass has the following properties: P ｎ -(1.14+0.192 ＊ P ｄ )>0.000 In the formula: P ｎ is represented by formula (I): The refractive index n at 587.56 nm is calculated from the glass composition in mole percent of the components according to ｄ are parameters that predict P ｄ is represented by formula (II): The density at room temperature d calculated from the glass composition in mole percent of the components according to ＲＴ is a parameter that predicts glass.

8. The composition of the components is 23.5 mol% or more and 25.5 mol% or less P ２ O ５ , 10.0 mol% or more and 40.0 mol% or less of Nb ２ O ５ , 4.5 mol% or more and 30.0 mol% or less of Bi ２ O ３ , 0.5 mol% or more and 40.0 mol% or less of TiO ２ , 0.3 mol% or more and 10.0 mol% or less of Li ２ O. 0.0 mol% or more and 15.0 mol% or less B ２ O ３ , BaO: 0.0 mol% or more and 10.0 mol% or less; 0.0 mol% or more and 10.0 mol% or less of CaO; K of 0.0 mol% or more and 10.0 mol% or less ２ O. 0.0 mol% or more and 10.0 mol% or less of Na ２ O, and 0.0 mol% or more and 10.0 mol% or less WO ３ , The glass of claim 7 comprising:

9. The composition of the components is 24.2 mol% or more and 25.0 mol% or less P ２ O ５ , 16.5 mol% or more and 30.5 mol% or less of Nb ２ O ５ , 13.0 mol% or more and 33.0 mol% or less of TiO ２ , 5.0 mol% or more and 23.0 mol% or less of Bi ２ O ３ , BaO of 1.75 mol% or more and 8.00 mol% or less, 0.3 mol% or more and 5.8 mol% or less of Li ２ O. 0.0 mol% or more and 9.0 mol% or less of CaO; 0.0 mol% or more and 7.5 mol% or less of K ２ O. 0.0 mol% or more and 6.0 mol% or less WO ３ , and 0 mol% or more and 5.75 mol% or less of Na ２ O. The glass of claim 7 comprising:

10. The composition of the components is such that: Alk ２ O+RO+Bi ２ O ３ +3 ＊ Al ２ O ３ -P ２ O ５ [モル%]≧0.000 Fulfilling In the formula, the chemical formula means the content of the corresponding component in the glass, and Alk ２ 10. The glass of claim 7, wherein O is the sum of alkali metal oxides and RO is the sum of divalent metal oxides.

11. In the above composition, Na ２ O+K ２ The glass according to any one of claims 7 to 9, wherein the total amount of O is 0.3 mol % or more.

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