Ion exchangeable glasses with high refractive index

Abstract

A glass composition includes: greater than or equal to 30 mol% and less than or equal to 50 mol% SiO2; greater than or equal to 0.5 mol% and less than or equal to 4.7 mol% Al2O3; greater than or equal to 14 mol% and less than or equal to 27 mol% Li2O; greater than or equal to 4 mol% and less than or equal to 11 mol% La2O3; greater than or equal to 4 mol% and less than or equal to 10 mol% Nb2O5; greater than or equal to 6.4 mol% and less than or equal to 25 mol% TiO2; and greater than or equal to 0 mol% and less than or equal to 7 mol% Na2O, wherein a product of Al2O3 × Na2O is less than or equal to 19 mol%2.

Description

Attorney Docket No. SP23-366PCT ION EXCHANGEABLE GLASSES WITH HIGH REFRACTIVE INDEX Priority

[0001] This application claims the benefit of priority under 35 U.S.C. §119 of U.S. ProvisionalApplication Serial No.63 / 606,226, filed on December 5, 2023, the content of which is relied upon and incorporated herein by reference in its entirety. Field

[0002] The present specification generally relates to glass compositions and, in particular toion exchangeable glass compositions having high refractive index. Technical Background

[0003] High refractive index glass articles have become increasingly desirable in commercialand industrial applications due to their optical properties. High refractive index glasses are particularly well suited for use as lenses due to their ability to efficiently redirect light. While medium refractive index glasses can achieve comparable results, these glasses require greater thicknesses to achieve similar optical performance as high refractive index glasses. Accordingly, as modern electronic devices and augmented reality devices have become thinner, high refractive index glasses have become more desirable as a replacement to thicker glass alternatives. However, commercially viable glass articles must be sufficiently robust to endure accidental dropping and regular contact without damage, such as scratching. High refractive index glasses have typically been ill-suited for such applications due to the difficulties associated with chemically strengthening high refractive index glasses.

[0004] Accordingly, a continual need exists for optically transparent, high refractive indexglasses that have improved mechanical properties. SUMMARY

[0005] According to a first aspect, A1, a glass composition may comprise: greater than or equalto 30 mol% and less than or equal to 50 mol% SiO2; greater than or equal to 0.5 mol% and less than or equal to 4.7 mol% Al2O3; greater than or equal to 14 mol% and less than or equal to 27 mol% Li2O; greater than or equal to 4 mol% and less than or equal to 9 mol% La2O3; greater than or equal to 4 mol% and less than or equal to 10 mol% Nb2O5; greater than or equal to 7Attorney Docket No. SP23-366PCT mol% and less than or equal to 25 mol% TiO2; and greater than or equal to 0 mol% and less than or equal to 7 mol% Na2O; wherein a product of Al2O3 × Na2O is less than or equal to 19 mol%2.

[0006] A second aspect A2 includes the glass composition according to the first aspect A1,wherein the product of Al2O3× Na2O is less than or equal to 18 mol%2.

[0007] A third aspect A3 includes the glass composition according to either the first or secondaspects A1-A2, wherein the glass composition comprises greater than or equal to 1 mol% and less than or equal to 4.5 mol% Al2O3.

[0008] A fourth aspect A4 includes the glass composition according to any of the first throughthird aspects A1-A3, wherein the glass composition comprises greater than or equal to 1 mol% and less than or equal to 6 mol% Na2O.

[0009] A fifth aspect A5 includes the glass composition according to any of the first throughfourth aspects A1-A4, wherein a ratio of TiO2 to La2O3 is greater than or equal to 0.6 and less than or equal to 3.

[0010] A sixth aspect A6 includes the glass composition according to according to the fifthaspect A5, wherein the ratio of TiO2to La2O3is greater than or equal to 1 and less than or equal to 2.

[0011] A seventh aspect A7 includes the glass composition according to any of the first throughsixth aspects A1-A6, wherein a sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5is greater than or equal to 27 mol%.

[0012] An eighth aspect A8 includes the glass composition according to any of the first throughseventh aspects A1-A7, wherein the glass composition is free or substantially free of P2O5.

[0013] A ninth aspect A9 includes the glass composition according to any of the first througheighth aspects A1-A8, wherein the glass composition comprises greater than 0 mol% and less than or equal to 3 mol% Y2O3.

[0014] A tenth aspect A10 includes the glass composition according to any of the first throughninth aspects A1-A9, wherein the glass composition comprises greater than 0 mol% and less than or equal to 4.5 mol% Ta2O5.Attorney Docket No. SP23-366PCT

[0015] An eleventh aspect A11 includes the glass composition according to any of the firstthrough tenth aspects A1-A10, wherein the glass composition comprises greater than 0 mol% and less than or equal to 12 mol% B2O3.

[0016] A twelfth aspect A12 includes the glass composition according to any of the firstthrough eleventh aspects A1-A11, wherein the glass composition comprises greater than 0 mol% and less than or equal to 5 mol% K2O.

[0017] A thirteenth aspect A13 includes the glass composition according to any of the firstthrough twelfth aspects A1-A12, wherein the glass composition comprises: greater than or equal to 0 mol% and less than or equal to 5 mol% BaO; greater than or equal to 0 mol% and less than or equal to 5 mol% SrO; greater than or equal to 0 mol% and less than or equal to 5 mol% ZnO; and greater than or equal to 0 mol% and less than or equal to 5 mol% CaO.

[0018] A fourteenth aspect A14 includes the glass composition according to any of the firstthrough thirteenth aspects A1-A13, wherein the glass composition comprises greater than or equal to 5 mol% and less than or equal to 9 mol% Nb2O5.

[0019] A fifteenth aspect A15 includes the glass composition according to any of the firstthrough fourteenth aspects A1-A14, wherein the glass composition comprises greater than or equal to 5 mol% and less than or equal to 8 mol% La2O3.

[0020] A sixteenth aspect A16 includes the glass composition according to any of the firstthrough fifteenth aspects A1-A15, wherein the glass composition comprises greater than or equal to 0 mol% and less than or equal to 9 mol% ZrO2.

[0021] A seventeenth aspect A17 includes the glass composition according to any of the firstthrough sixteenth aspects A1-A16, wherein the glass composition comprises greater than or equal to 8 mol% and less than or equal to 21 mol% TiO2.

[0022] An eighteenth aspect A18 includes the glass composition according to any of the firstthrough seventeenth aspects A1-A17, wherein the glass composition comprises greater than or equal to 14.5 mol% and less than or equal to 25 mol% Li2O.

[0023] A nineteenth aspect A19 includes the glass composition according to any of the firstthrough eighteenth aspects A1-A18, wherein the glass composition comprises greater than or equal to 33 mol% and less than or equal to 47 mol% SiO2.Attorney Docket No. SP23-366PCT

[0024] According to a twentieth aspect, A20, a glass article may comprise: greater than orequal to 30 mol% and less than or equal to 50 mol% SiO2; greater than or equal to 0.5 mol% and less than or equal to 4.7 mol% Al2O3; greater than or equal to 14 mol% and less than or equal to 27 mol% Li2O; greater than or equal to 0 mol% and less than or equal to 7 mol% Na2O, wherein a product of Al2O3mol % × Na2O mol % is less than or equal to 19 mol%2; and a sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5that is greater than or equal to 27 mol%, wherein the glass article is a chemically strengthened glass article and comprises: a refractive index (nd) at 589 nm greater than or equal to 1.795, and a surface compressive stress, after the chemical strengthening, greater than or equal to 230 MPa.

[0025] A twenty-first aspect A21 includes the glass article according to the twentieth aspectA20, wherein the product of Al2O3 × Na2O is less than or equal to 18 mol%2.

[0026] A twenty-second aspect A22 includes the glass article according to either the twentiethor twenty-first aspects A20-A21, wherein the glass article comprises greater than or equal to 1 mol% and less than or equal to 4.5 mol% Al2O3.

[0027] A twenty-third aspect A23 includes the glass article according to any of the twentieththrough twenty-second aspects A20-A22, wherein the glass article comprises greater than or equal to 1 mol% and less than or equal to 6 mol% Na2O.

[0028] A twenty-fourth aspect A24 includes the glass article according to any of the twentieththrough twenty-third aspects A20-A23, wherein a ratio of TiO2to La2O3is greater than or equal to 0.6 and less than or equal to 3.

[0029] A twenty-fifth aspect A25 includes the glass article according to the twenty-forth aspectA24, wherein the ratio of TiO2 to La2O3 is greater than or equal to 1 and less than or equal to 2.

[0030] A twenty-sixth aspect A26 includes the glass article according to any of the twentieththrough twenty-fifth aspects A20-A25, wherein the sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5 is greater than or equal to 29 mol%.

[0031] A twenty-seventh aspect A27 includes the glass article according to any of the twentieththrough twenty-sixth aspects A20-A26, wherein the glass article is free or substantially free of P2O5.Attorney Docket No. SP23-366PCT

[0032] A twenty-eighth aspect A28 includes the glass article according to any of the twentieththrough twenty-seventh aspects A20-A27, wherein the glass article comprises greater than 0 mol% and less than or equal to 3 mol% Y2O3.

[0033] A twenty-ninth aspect A29 includes the glass article according to any of the twentieththrough twenty-eighth aspects A20-A28, wherein the glass article comprises greater than 0 mol% and less than or equal to 4.5 mol% Ta2O5.

[0034] A thirtieth aspect A30 includes the glass article according to any of the twentieththrough twenty-ninth aspects A20-A29, wherein the glass article comprises greater than 0 mol% and less than or equal to 12 mol% B2O3.

[0035] A thirty-first aspect A31 includes the glass article according to any of the twentieththrough thirtieth aspects A20-A30, wherein the glass article comprises greater than 0 mol% and less than or equal to 5 mol% K2O.

[0036] A thirty-second aspect A32 includes the glass article according to any of the twentieththrough thirty-first aspects A20-A31, wherein the glass article comprises: greater than or equal to 0 mol% and less than or equal to 5 mol% BaO; greater than or equal to 0 mol% and less than or equal to 5 mol% SrO; greater than or equal to 0 mol% and less than or equal to 5 mol% ZnO; and greater than or equal to 0 mol% and less than or equal to 5 mol% CaO.

[0037] A thirty-third aspect A33 includes the glass article according to any of the twentieththrough thirty-second aspects A20-A32, wherein the glass article comprises greater than or equal to 5 mol% and less than or equal to 9 mol% Nb2O5.

[0038] A thirty-fourth aspect A34 includes the glass article according to any of the twentieththrough thirty-third aspects A20-A33, wherein the glass article comprises greater than or equal to 5 mol% and less than or equal to 8 mol% La2O3.

[0039] A thirty-fifth aspect A35 includes the glass article according to any of the twentieththrough thirty-fourth aspects A20-A34, wherein the glass article comprises greater than or equal to 0 mol% and less than or equal to 9 mol% ZrO2.

[0040] A thirty-sixth aspect A36 includes the glass article according to any of the twentieththrough thirty-fifth aspects A20-A35, wherein the glass article comprises greater than or equal to 8 mol% and less than or equal to 21 mol% TiO2.Attorney Docket No. SP23-366PCT

[0041] A thirty-seventh aspect A37 includes the glass article according to any of twentieththrough thirty-sixth aspects A20-A36, wherein the glass article comprises greater than or equal to 14.5 mol% and less than or equal to 25 mol% Li2O.

[0042] A thirty-eighth aspect A38 includes the glass article according to any of the twentieththrough thirty-seventh aspects A20-A37, wherein the glass article comprises greater than or equal to 33 mol% and less than or equal to 47 mol% SiO2.

[0043] A thirty-ninth aspect A39 includes the glass article according to any of the twentieththrough thirty-eighth aspects A20-A38, wherein the refractive index (nd) at 589 nm of the glass article is greater than or equal to 1.82.

[0044] A fortieth aspect A40 includes the glass article according to any of the twentieththrough thirty-ninth aspects A20-A39, wherein the glass article comprises a density less than 3.95 g / cm3.

[0045] A forty-first aspect A41 includes the glass article according to any of the twentieththrough fortieth aspects A20-A40, wherein the chemical strengthening comprises subjecting the glass article to an ion exchange bath comprising one or more molten salts, wherein the glass article is subjected to the ion exchange bath at a temperature greater than or equal to 380 °C.

[0046] A forty-second aspect A42 includes the glass article according to the forty-first aspectA41, wherein the ion exchange bath comprises NaNO3.

[0047] A forty-third aspect A43 includes the glass article according to the forty-first aspectA41, wherein the ion exchange bath comprises bath comprises NaNO3, KNO3, or combinations thereof.

[0048] A forty-fourth aspect A44 includes the glass article according to any of the forty-firstthrough forty-third aspects A41-A43, wherein the glass article comprises a glass transition temperature (Tg) greater than the temperature of the ion exchange bath.

[0049] A forty-fifth aspect A45 includes the glass article according to any of the forty-firstthrough forty-fourth aspects A41-A44, the glass article is subjected to the ion exchange bath comprising NaNO3 at a temperature of 430°C for 6 hours and 45 minutes, and wherein the glass article breaks into less than 100 pieces, as measured at an article thickness of 1 mm by a tip method.Attorney Docket No. SP23-366PCT

[0050] A forty-sixth aspect A46 includes the glass article according to any of the twentieththrough forty-fifth aspects A20-A45, wherein the glass article comprises a modulus of rupture (MOR) greater than 600 MPa when the glass article has a thickness of at least 1 mm.A forty- seventh aspect A47 includes the glass article according to any of the twentieth through forty- sixth aspects A20-A46, wherein the glass article comprises a peak surface compressive stress greater than or equal to 300 MPa.

[0051] A forty-eighth aspect A48 includes the glass article according to any of the twentieththrough forty-seventh aspects A20-A47, wherein the glass article comprises a maximum central tension greater than or equal to 40 MPa when the glass article has a thickness of at least 1 mm.

[0052] According to a forty-ninth aspect, A49, a glass composition may comprise: greater thanor equal to 33 mol% and less than or equal to 47 mol% SiO2; greater than or equal to 1 mol% and less than or equal to 4.5 mol% Al2O3; greater than or equal to 15 mol% and less than or equal to 25 mol% Li2O; greater than or equal to 4 mol% and less than or equal to 8 mol% La2O3; greater than or equal to 4 mol% and less than or equal to 8 mol% Nb2O5; greater than or equal to 8 mol% and less than or equal to 21 mol% TiO2; greater than or equal to 3 mol% and less than or equal to 8 mol% ZrO2; greater than or equal to 3 mol% and less than or equal to 6 mol% Na2O; wherein a product of Al2O3mol% × Na2O mol% is less than or equal to 19 mol%; and the glass composition is free or substantially free of P2O5.

[0053] A fiftieth aspect A50 includes the glass composition according to the forty-ninth aspectA49, wherein the product of Al2O3× Na2O is less than or equal to 18 mol%.

[0054] A fifty-first aspect A51 includes the glass composition according to the forty-ninth orfiftieth aspects A49-A50, wherein a ratio of TiO2 mol % to La2O3 mol% is greater than or equal to 0.6 and less than or equal to 3.

[0055] A fifty-second aspect A52 includes the glass article according to any of the forty-ninththrough fifty-first aspects A49-A51, wherein the ratio of TiO2 mol % to La2O3 mol% is greater than or equal to 1 and less than or equal to 2.

[0056] A fifty-third aspect A53 includes the glass article according to any of the forty-ninththrough fifty-second aspects A49-A52, wherein a sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5is greater than or equal to 27 mol%.Attorney Docket No. SP23-366PCT

[0057] A fifty-fourth aspect A54 includes the glass article according to any of the forty-ninththrough fifty-third aspects A49-A53, wherein the glass composition comprises greater than 0 mol% and less than or equal to 3 mol% Y2O3.

[0058] A fifty-fifth aspect A55 includes the glass article according to any of the forty-ninththrough fifty-fourth aspects A49-A54, wherein the glass composition comprises greater than 0 mol% and less than or equal to 4.5 mol% Ta2O5.

[0059] A fifty-sixth aspect A56 includes the glass article according to any of the forty-ninththrough fifty-fifth aspects A49-A55, wherein the glass composition comprises greater than 0 mol% and less than or equal to 12 mol% B2O3.

[0060] A fifty-seventh aspect A57 includes the glass article according to any of the forty-ninththrough fifty-sixth aspects A49-A56, wherein the glass composition comprises greater than 0 mol% and less than or equal to 5 mol% K2O.

[0061] A fifty-eighth aspect A58 includes the glass article according to any of the forty-ninththrough fifty-seventh aspects A49-A57, wherein the glass composition comprises: greater than or equal to 0 mol% and less than or equal to 5 mol% BaO; greater than or equal to 0 mol% and less than or equal to 5 mol% SrO; greater than or equal to 0 mol% and less than or equal to 5 mol% ZnO; and greater than or equal to 0 mol% and less than or equal to 5 mol% CaO.

[0062] A fifty-ninth aspect A59 includes a glass composition comprising greater than or equalto 30 mol% and less than or equal to 50 mol% SiO2; greater than or equal to 0.5 mol% and less than or equal to 4.7 mol% Al2O3; greater than or equal to 14 mol% and less than or equal to 27 mol% Li2O; greater than or equal to 4 mol% and less than or equal to 11 mol% La2O3; greater than or equal to 4 mol% and less than or equal to 10 mol% Nb2O5; greater than or equal to 6.4 mol% and less than or equal to 25 mol% TiO2; and greater than or equal to 0 mol% and less than or equal to 7 mol% Na2O, wherein a product of Al2O3 × Na2O is less than or equal to 19 mol%2.

[0063] A sixtieth aspect A60 includes a glass comopsotion of the aspect A59, wherein a ratioof TiO2 to La2O3 is greater than or equal to 0.55 and less than or equal to 4.

[0064] A sixty-first aspect A61 includes a glass composition of the aspect A60, wherein theratio of TiO2to La2O3is greater than or equal to 0.6 and less than or equal to 2.Attorney Docket No. SP23-366PCT

[0065] A sixty-second aspect A62 includes a glass composition of any of the aspects 59 to61, wherein a sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5 is greater than or equal to 29 mol%.

[0066] A sixty-third aspect A63 includes a glass composition of any of the aspects A59 toA62, wherein the glass composition is free or substantially free of P2O5.

[0067] A sixty-fourth aspect A64 includes a glass composition of any of the aspects A59 toA63, wherein the glass composition comprises greater than or equal to 5 mol% and less than or equal to 9 mol% Nb2O5.

[0068] A sixty-fifth aspect A65 includes a glass composition of any of the aspects A59 toA64, wherein the glass composition comprises greater than or equal to 8 mol% and less than or equal to 21 mol% TiO2.

[0069] A sixty-sixth aspect A66 includes a glass composition of any of the aspects A59 toA65, wherein the glass composition comprises greater than or equal to 14.5 mol% and less than or equal to 25 mol% Li2O.

[0070] A sixty-seventh aspect A67 includes a glass composition of any one of the aspectsA59 to A66, wherein the glass composition comprises greater than or equal to 33 mol% and less than or equal to 47 mol% SiO2.

[0071] A sixty-eighth aspect includes a glass article formed from a glass composition glasscomposition of any one of the aspects A59 to A67, wherein the glass article is a chemically strengthened glass article and comprises: a refractive index (nd) at 589 nm greater than or equal to 1.795, and a surface compressive stress, after the chemical strengthening, greater than or equal to 230 MPa.

[0072] A sixty-ninth aspect includes a glass article according to the aspect A68, wherein therefractive index (nd) at 589 nm of the glass article is greater than or equal to 1.82.

[0073] A seventieth aspect includes a glass article according to any of the aspects A68 toA69, wherein the glass article comprises a density less than 3.95 g / cm3.

[0074] A seventy-first aspect includes a glass article according to any of the aspects A68 toA70, when the glass article is subjected to an ion exchange bath comprising NaNO3 at a temperature of 430°C for 6 hours and 45 minutes, and the glass article breaks into less than 100 pieces, as measured at an article thickness of 1 mm by a tip method.

[0075] A seventy-second aspect includes a glass article according to the aspect A71, whereinthe glass article comprises a peak surface compressive stress greater than or equal to 270 MPa after being subjected to the ion exchange bath.Attorney Docket No. SP23-366PCT

[0076] A seventy-third aspect includes a glass article according to any of the aspects A68 toA72, wherein the glass article comprises a maximum central tension greater than or equal to 28 MPa when the glass article has a thickness of at least 1 mm.

[0077] Additional features and advantages of the glass compositions described herein will beset forth in the detailed description which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the embodiments described herein, including the detailed description which follows, the claims, as well as the appended drawings.

[0078] It is to be understood that both the foregoing general description and the followingdetailed description describe various embodiments and are intended to provide an overview or framework for understanding the nature and character of the claimed subject matter. The accompanying drawings are included to provide a further understanding of the various embodiments, and are incorporated into and constitute a part of this specification. The drawings illustrate the various embodiments described herein, and together with the description serve to explain the principles and operations of the claimed subject matter. BRIEFDESCRIPTION OF THEDRAWINGS

[0079] FIG. 1 is a photograph of a micrometric wheel and the impact probe used in the “TipMethod” described herein;

[0080] FIG. 2A is a representation of a non-frangible sample after a frangibility test;

[0081] FIG. 2B is another representation of a non-frangible sample after a frangibility test;

[0082] FIG. 3A is a representation of a low frangibility sample after a frangibility test;

[0083] FIG. 3B is another representation of a low frangibility sample after a frangibility test;

[0084] FIG. 4A is a representation of a frangible sample after a frangibility test;

[0085] FIG. 4B another representation of a frangible sample after a frangibility test;

[0086] FIG. 5 is a depiction of a cross-section of a glass article, according to embodimentsdescribed herein;Attorney Docket No. SP23-366PCT

[0087] FIG. 6A is an illustration of an exemplary electronic device incorporating any of theglass compositions or glass articles disclosed herein;

[0088] FIG. 6B is a perspective view of the exemplary electronic device of FIG. 6A;

[0089] FIG. 7 is a plot of the stress profile (y-axis: stress; in MPa) as a function of depth (x-axis: depth; in mm) from a surface of an example glass article after chemical strengthening, according to one or more embodiments described herein; and

[0090] FIG. 8 is a plot of the failure probability (y-axis: failure probability; in percentage (%))as a function of the force applied during a flexural test (x-axis: force; in MPa) of an example glass article, after chemical strengthening, according to one or more embodiments described herein. DETAILEDDESCRIPTION

[0091] Reference will now be made in detail to various embodiments of ion exchangeable glasscompositions having a high refractive index. According to some embodiments, a glass composition may comprise greater than or equal to 30 mol% and less than or equal to 50 mol% SiO2; greater than or equal to 0.5 mol% and less than or equal to 4.7 mol% Al2O3; greater than or equal to 14 mol% and less than or equal to 27 mol% Li2O; greater than or equal to 4 mol% and less than or equal to 9 mol% La2O3; greater than or equal to 4 mol% and less than or equal to 10 mol% Nb2O5; greater than or equal to 7 mol% and less than or equal to 25 mol% TiO2; and greater than or equal to 0 mol% and less than or equal to 7 mol% Na2O. The product of Al2O3 × Na2O is less than or equal to 19 mol%2. The glass compositions may also be substantially free or free of P2O5 to avoid devitrification and ensure glass quality, as described herein. Such glass compositions can be formed into glass articles that can be chemically strengthened as described herein. The glass articles may also exhibit a refractive index (nd) at 589 nm, prior to chemical strengthening, that is greater than or equal to 1.795, and a surface compressive stress, after the chemical strengthening, that is greater than or equal to 230 MPa.

[0092] According to some embodiments, a glass composition may comprise greater than orequal to 33 mol% and less than or equal to 47 mol% SiO2; greater than or equal to 1 mol% and less than or equal to 4.5 mol% Al2O3; greater than or equal to 15 mol% and less than or equal to 25 mol% Li2O; greater than or equal to 4 mol% and less than or equal to 8 mol% La2O3; greater than or equal to 4 mol% and less than or equal to 8 mol% Nb2O5; greater than or equalAttorney Docket No. SP23-366PCT to 8 mol% and less than or equal to 21 mol% TiO2; greater than or equal to 3 mol% and less than or equal to 8 mol% ZrO2; greater than or equal to 3 mol% and less than or equal to 6 mol% Na2O; wherein a product of Al2O3 mol% × Na2O mol% is less than or equal to 19 mol%2; and the glass composition is free or substantially free of P2O5.

[0093] Various embodiments of the glass compositions and glass articles formed therefromwill be described herein with specific reference to the appended drawings.

[0094] Ranges may be expressed herein as from “about” one particular value, and / or to “about”another particular value. When such a range is expressed, another embodiment includes from the one particular value and / or to the other particular value. Similarly, when values are expressed as approximations, by use of the antecedent “about,” it will be understood that the particular value forms another embodiment. It will be further understood that the endpoints of each of the ranges are significant both in relation to the other endpoint, and independently of the other endpoint.

[0095] Directional terms as used herein - for example up, down, right, left, front, back, top,bottom - are made only with reference to the figures as drawn and are not intended to imply absolute orientation.

[0096] Unless otherwise expressly stated, it is in no way intended that any method set forthherein be construed as requiring that its steps be performed in a specific order, nor that with any apparatus specific orientations be required. Accordingly, where a method claim does not actually recite an order to be followed by its steps, or that any apparatus claim does not actually recite an order or orientation to individual components, or it is not otherwise specifically stated in the claims or description that the steps are to be limited to a specific order, or that a specific order or orientation to components of an apparatus is not recited, it is in no way intended that an order or orientation be inferred, in any respect. This holds for any possible non-express basis for interpretation, including: matters of logic with respect to arrangement of steps, operational flow, order of components, or orientation of components; plain meaning derived from grammatical organization or punctuation, and; the number or type of embodiments described in the specification.Attorney Docket No. SP23-366PCT

[0097] As used herein, the singular forms “a,” “an” and “the” include plural referents unlessthe context clearly dictates otherwise. Thus, for example, reference to “a” component includes aspects having two or more such components, unless the context clearly indicates otherwise.

[0098] In the embodiments of the glass compositions and resultant glass articles describedherein, the concentrations of constituent components (i.e., SiO2, Al2O3, and the like) are specified in mole percent (mol%) on an oxide basis, unless otherwise specified.

[0099] The term “substantially free,” when used to describe the concentration and / or absenceof a particular constituent component in a glass composition and the resultant glass article, means that the constituent component is not intentionally added to the glass composition and the resultant glass article. However, the glass composition and the resultant glass article may contain traces of the constituent component as a contaminant or tramp in amounts of less than 0.05 weight percent (wt%). As noted herein, the remainder of the application specifies the concentrations of constituent component in mol%. The contaminant or tramp amounts of the constituent components are listed in wt% for manufacturing purposes and one skilled in the art would understand the contaminant and tramp amounts being listed in wt%.

[0100] The terms “0 mol%” and “free,” when used to describe the concentration and / orabsence of a particular constituent component in a glass composition and the resultant glass article, means that the constituent component is not present in glass composition and the resultant glass article.

[0101] Density, as described herein, is measured prior to chemical strengthening, inaccordance with the buoyancy method of ASTM C693-93.

[0102] Refractive index, as described herein, is measured prior to chemical strengthening,in accordance with ASTM E1967. The refractive index (nd) is measured using a Metricon apparatus at a wavelength of 589 nm.

[0103] The stress profile, the surface compressive stress (CS), and the central tension (CT)of the glass articles are measured using a scattered polarization method known in the art. The values reported for central tension (CT) herein refer to the central tension at half the thickness of the glass, unless otherwise indicated. The SCALP technique refers to a Scattered Light Polariscope (SCALP), such as a SCALP-05 portable scattered light polariscope.Attorney Docket No. SP23-366PCT

[0104] According to the convention normally used in the art, compression or compressivestress (CS) is expressed as a negative (i.e., < 0) stress and tension or tensile stress is expressed as a positive (i.e., > 0) stress. Throughout this description, however, CS is expressed as a positive or absolute value (i.e., as recited herein, CS = |CS|).

[0105] As used herein, “modulus of rupture (MOR)” refers to the maximum stress of asample at its moment of yield during a flexural test. The MOR is determined by a ring on ring (ROR) test with standardized equipment, such as an Instron instrument, in accordance with ASTM C1499.

[0106] As used herein, the “frangibility limit” refers to the central tension or stored strainenergy above which the glass article exhibits frangible behavior. “Frangibility” or “frangible behavior” refers to fracture behavior, specifically the resultant number of fractured glass pieces or fragments, when a material is subjected to an impact or insult. A glass article is considered “non-frangible” if it breaks into two pieces or does not break at all due to an impact according to the procedure described below. A glass article is considered to have “low frangibility” or considered to be close to the frangibility limit if a glass article breaks into greater than two and less than or equal to 10 pieces due to an impact according to the procedure described below. A glass article is considered “frangible” if a glass article breaks into more than 10 pieces due to an impact according to the procedure described below. Frangibility can be assessed using the “Tip Method” wherein, an impact probe is brought in to contact with glass article. The impact probe may be fixed on a stem and the glass article may be located on a plate beneath the impact probe, as shown in FIG.1. The plate and glass article are then moved upwards along the z axis via a micro-metric wheel until the glass article contacts the impact probe. Frangibility results of examples reported herein utilized manual turning of the micro-metric wheel to apply force to the glass articles until breakage. However, an automated method, where the plate and glass article are gradually raised at a rate of 50 µm per 15 seconds (via electrically controlled actuation of the micro-wheel) until the glass article fractures, could also be used. The gradual application of force using the Tip Method produces a delayed fracture mechanism and prevents the influence of external, impact forces that would prevent the accurate determination of the frangible behavior of the glass article. In embodiments, the test area is any 25 mm by 25 mm square centered at the impact point. While coatings, adhesive layers, and the like may be used in conjunction with the glass described herein, such external restraints are not used in determining the frangibility or frangible behavior of the glass article. In embodiments, a filmAttorney Docket No. SP23-366PCT that does not affect the fracture behavior of the multi-phase glass may be applied to the glass article prior to the frangibility test to prevent the ejection of fragments from the glass article.

[0107] FIG. 2A depicts a non-frangible test result. As shown in FIG. 2A, the test area is asquare that is centered at the impact point 130, where the length of a side of the square a is 25mm. The sample shown in FIG. 2A includes two fragments 142 and no branches. Because the sample shown in FIG.2A fractures into only two fragments, it is considered non-frangible.

[0108] FIG. 2B depicts a low frangibility test result. As shown in FIG. 2B, the lowfrangibility sample is centered at the impact point 130 and includes six fragments 142 and no branches. Since the sample shown in FIG. 1B breaks into less than ten fragments, it is considered non-frangible.

[0109] Another low frangibility sample is depicted in FIG. 3A. The sample shown in FIG.3A is centered at the impact point 130 and includes nine fragments 142 and three branches 140. Since the sample shown in FIG. 3A fractures into less than 10 fragments, it is considered to have a low frangibility.

[0110] Another low frangibility sample is depicted in FIG. 3B. As shown in FIG. 3B, thesample is centered at the impact point 130 and includes seven fragments 142 and one branch 140. Since the sample shown in FIG.3B fractures into ten or fewer fragments, it is considered to have a low frangibility.

[0111] A frangible sample is depicted in FIG. 4A. The sample is centered at the impact point130 and includes seventeen fragments 142 having twelve branches 140. Since the sample shown in FIG.4A contains more than 10 fragments, it is considered frangible.

[0112] Another frangible sample is depicted in FIG. 4B. The sample is centered at theimpact point 130 and includes nineteen fragments 142 having twelve crack branches 140. Since the sample depicted in FIG. 4B breaks into more than ten fragments, the sample is considered frangible.

[0113] In the frangibility test described herein, the impact is delivered to the surface of theglass article with a force that is just sufficient to release the internally stored energy present within the strengthened glass article. That is, the point impact force is sufficient to create atAttorney Docket No. SP23-366PCT least one new crack at the surface of the strengthened glass sheet and extend the crack through the compressive stress layer into the region that is under central tension (CT).

[0114] Chemical strengthening processes have traditionally been used to achieve improvedmechanical properties in alkali silicate glasses. For example, alkali oxides may be added to the glass composition to enable ion exchangeability, producing improved glass articles with a higher Young’s modulus, fracture toughness, scratch resistance, surface compressive stress, central tension, and modulus of rupture.

[0115] High refractive index glasses are often desirable for their optical properties. Theseglasses can be particularly useful in creating specialized lenses. High refractive index glass articles may be produced by adding certain transition metal oxides, alkaline earth oxides, or lanthanide oxides to the glass composition to modify the glass network. Yet, the addition of these high refractive index oxides may increase the density of the resultant glass article, which may interfere with the ion exchangeability thereof. As such, high refractive index glasses may not possess the mechanical properties desired for certain applications.

[0116] Disclosed herein are glass compositions and glass articles formed therefrom whichmitigate the aforementioned problems. Specifically, the glass compositions and resultant glass articles disclosed herein balance the inclusion of traditional glass network formers with high refractive index oxides to raise the refractive index of the glass while limiting its density. Additionally, the glass compositions maintain key compositional relationships, like the relationship of Al2O3to Na2O to maintain glass stability and avoid phase separation and the relationship of TiO2to La2O3to avoid devitrification that would compromise the optical transparency of the glass. As a result of these compositional features, embodiments of the present disclosure produce an optically transparent, ion exchangeable glass article with a high refractive index. As used herein, the term “optically transparent” means that the glass article exhibits a photopic transmittance of greater than or equal to 75%. Photopic transmittance is generally calculated as the tristimulus Y value of transmitted light, according to CIE color space conventions.

[0117] The glass compositions described herein may be described as aluminosilicate glasscompositions. The compositions of the present application include SiO2, Al2O3, Li2O, La2O3, Nb2O5, TiO2, and have a relatively low product of Al2O3and Na2O (e.g., Al2O3mol% * Na2O mol% is less than or equal to 19 mol%2). As a result, the glass compositions described hereinAttorney Docket No. SP23-366PCT have an amorphous structure, a density less than 3.95 g / cm3, and a refractive index higher than 1.795 as measured at 589 nm, resulting in an optically transparent, ion exchangeable, high refractive index glass article.

[0118] SiO2 is the primary glass former in the glass compositions described herein and mayfunction to stabilize the network structure of the glass articles and dictate the stability of the glass article. The concentration of SiO2in the glass compositions and resultant glass articles should be sufficiently high (e.g., greater than or equal to 30 mol%) to provide basic glass forming capability and produce a chemically stable glass structure. The amount of SiO2may be limited (e.g., to less than or equal to 50 mol%) to control the melting point of the glass composition, as the melting temperature of pure SiO2 or high SiO2 glasses can be undesirably high. Thus, limiting the concentration of SiO2 may aid in improving the meltability and the formability of the resulting glass article. Furthermore, controlling the SiO2 concentration in the glass composition and resultant glass article can dictate the Tg of the resulting glass article, because the Tg of the glass increases as the SiO2 concentration increases. In embodiments, the concentration of SiO2 is controlled to limit the Tg of the glass composition to be less than 700°C (e.g., greater than or equal to 520°C and less than or equal to 650°C, or even greater than or equal to 530°C and less than or equal to 580°C) to facilitate compatibility with existing equipment for forming glass articles.

[0119] Accordingly, in embodiments, the glass composition and resultant glass article maycomprise greater than or equal to 30 mol% and less than or equal to 50 mol% SiO2. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 33 mol% and less than or equal to 47 mol% SiO2. In embodiments, the concentration of SiO2 in the glass composition and the resultant glass article may be greater than or equal to 30 mol%, greater than or equal to 33 mol%, greater than or equal to 35 mol%, or even greater than or equal to 38 mol%. In embodiments, the concentration of SiO2 in the glass composition and the resultant glass article may be less than or equal to 50 mol%, less than or equal to 47 mol%, less than or equal to 45 mol%, or even less than or equal to 43 mol%. In embodiments, the concentration of SiO2in the glass composition and the resultant glass article may be greater than or equal to 30 mol% and less than or equal to 50 mol%, greater than or equal to 30 mol% and less than or equal to 47 mol%, greater than or equal to 30 mol% and less than or equal to 45 mol%, greater than or equal to 30 mol% and less than or equal to 43 mol%, greater than or equal to 33 mol% and less than or equal to 50 mol%, greater than or equal to 33 mol% and lessAttorney Docket No. SP23-366PCT than or equal to 47 mol%, greater than or equal to 33 mol% and less than or equal to 45 mol%, greater than or equal to 33 mol% and less than or equal to 43 mol%, greater than or equal to 35 mol% and less than or equal to 50 mol%, greater than or equal to 35 mol% and less than or equal to 47 mol%, greater than or equal to 35 mol% and less than or equal to 45 mol%, greater than or equal to 35 mol% and less than or equal to 44 mol%, greater than or equal to 38 mol% and less than or equal to 50 mol%, greater than or equal to 38 mol% and less than or equal to 47 mol%, greater than or equal to 38 mol% and less than or equal to 45 mol%, or even greater than or equal to 38 mol% and less than or equal to 43 mol%, or any and all sub-ranges formed from any of these endpoints.

[0120] Like SiO2, Al2O3 stabilizes the glass network and additionally provides increasedchemical stability and more efficient ion exchange to the resulting glass article. Al2O3 may react with alkali ions in the glass composition, including Li2O, Na2O and / or K2O, to produce increased ion exchange capability. Furthermore, alkali ions can act as a charge compensator in the presence of Al2O3 to form AlO4, increasing interdiffusion for efficient ion exchange. The amount of Al2O3 may also be tailored to the control the glass stability of the glass composition and the resultant glass article. The concentration of Al2O3 should be sufficiently high (i.e., greater than or equal to 0.5 mol%) such that the glass composition and the resultant glass article have a stabilized network and exhibit improved ion exchange characteristics. However, if the amount of Al2O3is too high (i.e., greater than 4.7 mol%), the glass may no longer be an amorphous, transparent glass, but instead may exhibit opalization as a result of phase separation due to the creation of an unwanted glass phase primarily comprising Al, Na, and Si, thereby diminishing the optical transparence of the glass. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 0.5 mol% and less than or equal to 4.7 mol% Al2O3. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 1 mol% and less than or equal to 4.5 mol% Al2O3. In embodiments, the concentration of Al2O3 in the glass composition and resultant glass article may be greater than or equal to 0.5 mol%, greater than or equal to 1 mol%, greater than or equal to 1.5 mol%, or even greater than or equal to 2 mol%. In embodiments, the concentration of Al2O3 in the glass composition and the resultant glass article may be less than or equal 4.7 mol%, less than or equal to 4.5 mol%, less than or equal to 4 mol%, or even less than or equal to 3.5 mol%. In embodiments, the concentration of Al2O3in the glass composition and the resultant glass article may be greater than or equal 0.5 mol% and less than or equal to 4.7 mol%, greater than or equal 0.5 mol% and less than or equal to 4.5 mol%, greater than or equal 0.5Attorney Docket No. SP23-366PCT mol% and less than or equal to 4 mol%, greater than or equal 0.5 mol% and less than or equal to 3.5 mol%, greater than or equal 1 mol% and less than or equal to 4.7 mol%, greater than or equal 1 mol% and less than or equal to 4.5 mol%, greater than or equal 1 mol% and less than or equal to 4 mol%, greater than or equal 1 mol% and less than or equal to 3.5 mol%, greater than or equal 1.5 mol% and less than or equal to 4.7 mol%, greater than or equal 1.5 mol% and less than or equal to 4.5 mol%, greater than or equal 1.5 mol% and less than or equal to 4 mol%,greater than or equal 1.5 mol% and less than or equal to 3.5 mol%, greater than or equal 2mol% and less than or equal to 4.7 mol%, greater than or equal 2 mol% and less than or equal to 4.5 mol%, greater than or equal 2 mol% and less than or equal to 4 mol%, or even greater than or equal 2 mol% and less than or equal to 3.5 mol%, or any and all sub-ranges formed from any of these endpoints.

[0121] As described hereinabove, the glass compositions and the resultant glass articles maycontain alkali oxides, such as Li2O, to enable the ion exchangeability of the glass compositions. Li2O aids in the ion exchangeability of the glass composition. The glass composition and the resultant glass article may comprise greater than or equal to 14 mol% and less than or equal to 27 mol% Li2O. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 14.5 mol% and less than or equal to 25 mol% Li2O. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 15 mol% and less than or equal to 25 mol% Li2O. In embodiments, the concentration of Li2O in the glass composition and the resultant glass article may be greater than or equal to 14 mol%, greater than or equal to 14.5 mol%, greater than or equal to 15 mol%, greater than or equal to 15.5 mol%, greater than or equal to 16 mol%, or even greater than or equal to 16.5 mol%. In embodiments, the concentration of Li2O in the glass composition and the resultant glass article may be less than or equal to 27 mol%, less than or equal to 25 mol% or even less than or equal to 23 mol%. In embodiments, the concentration of Li2O in the glass composition and the resultant glass article may be greater than or equal to 14 mol% and less than or equal to 27 mol%, greater than or equal to 14 mol% and less than or equal to 25 mol%, greater than or equal to 14 mol% and less than or equal to 23 mol%, greater than or equal to 14.5 mol% and less than or equal to 27 mol%, greater than or equal to 14.5 mol% and less than or equal to 25 mol%, greater than or equal to 14.5 mol% and less than or equal to 23 mol%, greater than or equal to 15 mol% and less than or equal to 27 mol%, greater than or equal to 15 mol% and less than or equal to 25 mol%, greater than or equal to 15 mol% and less than or equal to 23 mol%, greater than or equal to 15.5 mol% and less than or equal to 27 mol%, greater than or equal toAttorney Docket No. SP23-366PCT 15.5 mol% and less than or equal to 25 mol%, greater than or equal to 15.5 mol% and less than or equal to 23 mol%, greater than or equal to 16 mol% and less than or equal to 27 mol%, greater than or equal to 16 mol% and less than or equal to 25 mol%, greater than or equal to 16 mol% and less than or equal to 23 mol%, greater than or equal to 16.5 mol% and less than or equal to 27 mol%, greater than or equal to 16.5 mol% and less than or equal to 25 mol%, or even greater than or equal to 16.5 mol% and less than or equal to 23 mol%, or any and all sub- ranges formed from any of these endpoints.

[0122] As described hereinabove, the glass compositions and the resultant glass articles maycontain additional alkali oxides, such as Na2O, to enable ion exchangeability of the glass. Na2O aids in the ion exchangeability of the glass composition. Specifically, Na2O can facilitate ion exchange in chemical strengthening procedures that use an ion exchange bath comprising both NaNO3 and KNO3. The inclusion of Na2O in these ion exchange processes can obtain different stress profiles when compared to glasses that are chemically strengthened without Na2O in pure NaNO3 baths. The glass composition and the resultant glass article may comprise greater than or equal to 0 mol% and less than or equal to 7 mol% Na2O. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 1 mol% and less than or equal to 6 mol% Na2O. In embodiments, the glass composition and the resultant glass article may comprise greater than or equal to 3 mol% and less than or equal to 6 mol% Na2O. In embodiments, the concentration of Na2O in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater than or equal to 1 mol%, greater than or equal to 2 mol%, greater than or equal to 3 mol% or even greater than or equal to 4 mol%. In embodiments, the concentration of Na2O in the glass composition and the resultant glass article may be less than or equal to 7 mol%, less than or equal to 6.5 mol% or even less than or equal to 6 mol%. In embodiments, the concentration of Na2O in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 7 mol%, greater than or equal to 0 mol% and less than or equal to 6.5 mol%, greater than or equal to 0 mol% and less than or equal to 6 mol%, greater than or equal to 0.1 mol% and less than or equal to 7 mol%, greater than or equal to 0.1 mol% and less than or equal to 6.5 mol%, greater than or equal to 0.1 mol% and less than or equal to 6 mol%, greater than or equal to 1 mol% and less than or equal to 7 mol%, greater than or equal to 1 mol% and less than or equal to 6.5 mol%, greater than or equal to 1 mol% and less than or equal to 6 mol%, greater than or equal to 2 mol% and less than or equal to 7 mol%, greater than or equal to 2 mol% and less than or equal to 6.5 mol%, greater than or equal to 2 mol%Attorney Docket No. SP23-366PCT and less than or equal to 6 mol%, greater than or equal to 3 mol% and less than or equal to 7 mol%, greater than or equal to 3 mol% and less than or equal to 6.5 mol%, or even greater than or equal to 3 mol% and less than or equal to 6 mol%, greater than or equal to 4 mol% and less than or equal to 7 mol%, greater than or equal to 4 mol% and less than or equal to 6.5 mol%, or even greater than or equal to 4 mol% and less than or equal to 6 mol%, or any and all sub- ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of Na2O.

[0123] The relationship between Al2O3 and Na2O can effect the stability of the glasscomposition and the resultant glass article. In particular, as described herein, the presence of Al2O3 in certain concentrations may cause phase separation, resulting in opalization of the glass. Na2O may be used as a glass network modifier and to decrease the melting temperature of the glass composition. Additionally, the inclusion of Na2O may enable ion exchangeability of glass articles when treated in KNO3 or KNO3 and NaNO3 molten salt baths. As such, in the glass compositions and resultant articles described herein the product of Al2O3 × Na2O is limited (i.e., less than or equal to 19 mol%2) to prevent phase separation and opalization within the glass structure. Phase separation within the glass structure can diminish the optical properties and overall appearance of the resultant glass articles. In embodiments, the product of Al2O3× Na2O in the glass composition and the resultant glass article may be less than or equal to 19 mol%2, less than or equal to 18.5 mol%2, less than or equal to 18 mol%2, less than or equal to 17.5 mol%2, less than or equal to 17 mol%2, less than or equal to 16.5 mol%2, less than or equal to 16 mol%2, less than or equal to 15.5 mol%2, or even less than or equal to 15 mol%2.

[0124] In embodiments, the glass compositions and the resultant glass articles may containother alkali oxides, such as K2O, to enable ion exchangeability, lower viscosity, increase diffusivity, and lower the liquidus temperature. The glass composition and the resultant glass article may comprise greater than or equal to 0 mol% and less than or equal to 5 mol% K2O. In embodiments, the concentration of K2O in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol% or even greater than or equal to 1 mol%. In embodiments, the concentration of K2O in the glass composition and the resultant glass article may be less than or equal to 5 mol%, less than or equal to 4 mol% or even less than or equal to 3 mol%. In embodiments, the concentration of K2O in the glass composition and the resultant glass articleAttorney Docket No. SP23-366PCT may be greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0 mol% and less than or equal to 4 mol%, greater than or equal to 0 mol% and less than or equal to 3 mol%, greater than or equal to 0.1 mol% and less than or equal to 5 mol%, greater than or equal to 0.1 mol% and less than or equal to 4 mol%, greater than or equal to 0.1 mol% and less than or equal to 3 mol%, greater than or equal to 1 mol% and less than or equal to 5 mol%, greater than or equal to 1 mol% and less than or equal to 4 mol%, or even greater than or equal to 1 mol% and less than or equal to 3 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of K2O.

[0125] Certain transition metal oxides, alkaline earth oxides, and / or lanthanide oxidesincluding La2O3, Nb2O5, TiO2, ZrO2, Y2O3 and Ta2O5 may be added to the glass composition or resultant glass article to achieve a relatively high refractive index (e.g., nd above 1.795). However, the proportions of these high refractive index oxides should be balanced to achieve a stable, amorphous glass structure with a relatively low density (e.g. below 3.95 g / cm3) to enable ion exchangeability.

[0126] As described hereinabove, the glass compositions and the resultant glass articlesinclude La2O3. La2O3increases the refractive index of the glass composition and the resulting glass article, while also increasing the fracture toughness and other desirable mechanical properties. However, including too much La2O3(e.g., greater than 9 mol%) may increase the density of the glass composition or resultant glass article, reducing ion exchangeability. The glass composition and the resultant glass article may comprise greater than or equal to 4 mol% and less than or equal to 9 mol% La2O3. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 4 mol% and less than or equal to 8 mol% La2O3. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 5 mol% and less than or equal to 8 mol% La2O3. In embodiments, the concentration of La2O3 in the glass composition and the resultant glass article may be greater than or equal to 4 mol%, greater than or equal to 4.5 mol%, greater than or equal to 5 mol%, greater than or equal to 5.5 mol%, greater than or equal to 6 mol%, or even greater than or equal to 6.5 mol%. In embodiments, the concentration of La2O3 in the glass composition and the resultant glass article may be less than or equal to 9 mol%, less than or equal to 8 mol% or even less than or equal to 7.5 mol%. In embodiments, the concentration of Li2O in the glass composition and the resultant glass article may be greater than or equal to 4 mol% and lessAttorney Docket No. SP23-366PCT than or equal to 9 mol%, greater than or equal to 4 mol% and less than or equal to 8 mol%, greater than or equal to 4 mol% and less than or equal to 7.5 mol%, greater than or equal to 4.5 mol% and less than or equal to 9 mol%, greater than or equal to 4.5 mol% and less than or equal to 8 mol%, greater than or equal to 4.5 mol% and less than or equal to 7.5 mol%, greater than or equal to 5 mol% and less than or equal to 9 mol%, greater than or equal to 5 mol% and less than or equal to 8 mol%, greater than or equal to 5 mol% and less than or equal to 7.5 mol%, greater than or equal to 5.5 mol% and less than or equal to 9 mol%, greater than or equal to 5.5 mol% and less than or equal to 8 mol%, greater than or equal to 5.5 mol% and less than or equal to 7.5 mol%, greater than or equal to 6 mol% and less than or equal to 9 mol%, greater than or equal to 6 mol% and less than or equal to 8 mol%, even greater than or equal to 6 mol% and less than or equal to 7.5 mol%, greater than or equal to 6.5 mol% and less than or equal to 9 mol%, greater than or equal to 6.5 mol% and less than or equal to 8 mol%, or even greater than or equal to 6.5 mol% and less than or equal to 7.5 mol%, or any and all sub-ranges formed from any of these endpoints.

[0127] Additionally, the relationship between TiO2 and La2O3 can effect the stability and ionexchangeability of the glass composition and the resultant glass article. When the ratio of TiO2 to La2O3is too high (e.g., greater than or equal to 3), the glass stability may suffer and phase separation and crystallization may occur within the glass structure, diminishing optical transparency. However, when the ratio of TiO2to La2O3is too low (e.g., less than 0.6), the density of the glass composition and resultant glass article may become too high, reducing the ion exchangeability of the glass. As such, in the glass compositions and resultant articles described herein the ratio of TiO2 to La2O3 is controlled to ensure that it is maintained within an optimal range. The ratio of TiO2 to La2O3 in the glass composition and the resultant glass article may comprise greater than or equal to 0.6 and less than or equal to 3. In embodiments, the ratio of TiO2 to La2O3 in the glass composition and the resultant glass article may comprise greater than or equal to 1 and less than or equal to 2. In embodiments, the ratio of TiO2 to La2O3 in the glass composition and the resultant glass article may be greater than or equal to 0.6, greater than or equal to 0.85, greater than or equal to 1, greater than or equal to 1.15, greater than or equal to 1.3, or even greater than or equal to 1.5. In embodiments, the ratio of TiO2 to La2O3 in the glass composition and the resultant glass article may be less than or equal to 3, less than or equal to 2.5 mol% or even less than or equal to 2 mol%. In embodiments the ratio of TiO2mol% to La2O3mol% in the glass composition and the resultant glass article may be greater than or equal to 0.6 and less than or equal to 3, greater than or equal to 0.6 and less thanAttorney Docket No. SP23-366PCT or equal to 2.5, greater than or equal to 0.6 and less than or equal to 2, greater than or equal to 0.85 and less than or equal to 3, greater than or equal to 0.85 and less than or equal to 2.5, greater than or equal to 0.85 and less than or equal to 2, greater than or equal to 1 and less than or equal to 3, greater than or equal to 1 and less than or equal to 2.5, greater than or equal to 1 and less than or equal to 2, greater than or equal to 1.15 and less than or equal to 3, greater than or equal to 1.15 and less than or equal to 2.5, greater than or equal to 1.15 and less than or equal to 2, greater than or equal to 1.3 and less than or equal to 3, greater than or equal to 1.3 and less than or equal to 2.5, greater than or equal to 1.3 and less than or equal to 2, greater than or equal to 1.5 and less than or equal to 3, greater than or equal to 1.5 and less than or equal to 2.5, or even greater than or equal to 1.5 and less than or equal to 2, or any and all sub-ranges formed from any of these endpoints.

[0128] Likewise, the glass compositions and the resultant glass articles also include Nb2O5.Nb2O5 increases the refractive index of the glass composition and the resulting glass article. Including too little Nb2O5 (e.g., less than 4 mol%) can negatively affect the density of the glass by requiring the inclusion of alternative high refractive index oxides with greater effects on the density of the glass for comparable increases in the refractive index. However, including too much Nb2O5(e.g., greater than 10 mol%) can negatively affect the chemical stability of the glass composition and resultant glass article, causing devitrification and loss of optical transparency. The glass composition and the resultant glass article may comprise greater than or equal to 4 mol% and less than or equal to 10 mol% Nb2O5. In embodiments, the glass composition and the resultant glass article may comprise than or equal to 5 mol% and less than or equal to 9 mol% Nb2O5. In embodiments, the glass composition and the resultant glass article may comprise than or equal to 4 mol% and less than or equal to 8 mol% Nb2O5. In embodiments, the concentration of Nb2O5 in the glass composition and the resultant glass article may be greater than or equal to 4 mol%, greater than or equal to 4.5 mol%, greater than or equal to 5 mol%, greater than or equal to 5.5 mol%, or even greater than or equal to 6 mol%. In embodiments, the concentration of Nb2O5 in the glass composition and the resultant glass article may be less than or equal to 10 mol%, less than or equal to 9 mol%, less than or equal to 8 mol%, less than or equal to 7.5 mol% or even less than or equal to 7 mol%. In embodiments, the concentration of Nb2O5 in the glass composition and the resultant glass article may be greater than or equal to 4 mol% and less than or equal to 10 mol%, greater than or equal to 4 mol% and less than or equal to 9 mol%, greater than or equal to 4 mol% and less than or equal to 8 mol%, greater than or equal to 4 mol% and less than or equal to 7.5 mol%,Attorney Docket No. SP23-366PCT greater than or equal to 4 mol% and less than or equal to 7 mol%, greater than or equal to 4.5 mol% and less than or equal to 10 mol%, greater than or equal to 4.5 mol% and less than or equal to 9 mol%, greater than or equal to 4.5 mol% and less than or equal to 8 mol%, greater than or equal to 4.5 mol% and less than or equal to 7.5 mol%, greater than or equal to 4.5 mol% and less than or equal to 7 mol%, greater than or equal to 5 mol% and less than or equal to 10 mol%, greater than or equal to 5 mol% and less than or equal to 9 mol%, greater than or equal to 5 mol% and less than or equal to 8 mol%, greater than or equal to 5 mol% and less than or equal to 7.5 mol%, greater than or equal to 5 mol% and less than or equal to 7 mol%, greater than or equal to 5.5 mol% and less than or equal to 9 mol%, greater than or equal to 5.5 mol% and less than or equal to 8 mol%, greater than or equal to 5.5 mol% and less than or equal to 7.5 mol%, greater than or equal to 5.5 mol% and less than or equal to 7 mol%, greater than or equal to 6 mol% and less than or equal to 10 mol%, greater than or equal to 6 mol% and less than or equal to 9 mol%, greater than or equal to 6 mol% and less than or equal to 8 mol%, greater than or equal to 6 mol% and less than or equal to 7.5 mol%, greater than or equal to 6 mol% and less than or equal to 7 mol%, or any and all sub-ranges formed from any of these endpoints.

[0129] The glass compositions and resultant glass articles described herein also includeTiO2. TiO2increases the refractive index of the glass. Including too little TiO2(e.g., less than 7 mol%) can negatively affect the density of the glass by requiring the inclusion of alternative high refractive index oxides with greater effects on the density of the glass for comparable increases in the refractive index. However, including too much TiO2(e.g., greater than 25 mol%) can have negative consequences by increasing the density of the glass too much, thereby reducing ion exchangeability. Additionally, adding too much TiO2 can decrease the transmittance of blue light through the glass composition and resulting glass article, which may be undesirable in certain application. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 7 mol% and less than or equal to 25 mol% TiO2. In embodiments, the glass composition and resultant glass article may comprise greater than or equal to 8 mol% and less than or equal to 21 mol% TiO2. In embodiments, the concentration of TiO2 in the glass composition and resultant glass article may be greater than or equal to 7 mol%, greater than or equal to 8 mol%, greater than or equal to 9 mol%, greater than or equal to 10 mol%, greater than or equal to 11 mol%, or even greater than or equal to 12 mol%. In embodiments, the concentration of TiO2in the glass composition and the resultant glass article may be less than or equal 25 mol%, less than or equal to 22 mol%, or even less than or equalAttorney Docket No. SP23-366PCT to 18 mol%. In embodiments, the concentration of TiO2 in the glass composition and the resultant glass article may be greater than or equal to 7 mol% and less than or equal to 25 mol%, greater than or equal to 7 mol% and less than or equal to 22 mol%, greater than or equal to 7 mol% and less than or equal to 18 mol%, greater than or equal to 8 mol% and less than or equal to 25 mol%, greater than or equal to 8 mol% and less than or equal to 21 mol%, greater than or equal to 8 mol% and less than or equal to 17.5 mol%, greater than or equal to 9 mol% and less than or equal to 25 mol%, greater than or equal to 9 mol% and less than or equal to 22 mol%, greater than or equal to 9 mol% and less than or equal to 18 mol%, greater than or equal to 10 mol% and less than or equal to 25 mol%, greater than or equal to 10 mol% and less than or equal to 22 mol%, greater than or equal to 10 mol% and less than or equal to 18 mol%, greater than or equal to 11 mol% and less than or equal to 25 mol%, greater than or equal to 11 mol% and less than or equal to 22 mol%, greater than or equal to 11 mol% and less than or equal to 18 mol%, greater than or equal to 12 mol% and less than or equal to 25 mol%, greater than or equal to 12 mol% and less than or equal to 22 mol%, or even greater than or equal to 12 mol% and less than or equal to 18 mol%, or any and all sub-ranges formed from any of these endpoints.

[0130] The glass compositions and resultant glass articles described herein also includeZrO2. ZrO2may be added to increase the refractive index and increase the mechanical properties of the glass composition and resultant glass article. However, including too much ZrO2(e.g., greater than to 9 mol%) can have negative effects by increasing the density and reducing the ion exchangeability of the glass. In embodiments, the glass composition and the resultant glass article may comprise greater than 0 mol% and less than or equal to 9 mol% ZrO2. In embodiments, the concentration of ZrO2 in the glass composition and the resultant glass article may be greater than or equal to 3 mol% and less than or equal to 8 mol%. In embodiments, the concentration of ZrO2 in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 3 mol%, greater than or equal to 3.5 mol%, greater than or equal to 4 mol%, or even greater than or equal to 4.5 mol%. In embodiments, the concentration of ZrO2in the glass composition and the resultant glass article may be less than or equal to 9 mol%, less than or equal to 8 mol% or even less than or equal to 7 mol%. In embodiments, the concentration of ZrO2 in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 9 mol%, greater than or equal to 0 mol% and less than or equal to 8 mol%, greater than or equal to 0 mol% and less than or equal to 7 mol%, greater than or equal to 3 mol% and less than or equal to 9 mol%,Attorney Docket No. SP23-366PCT greater than or equal to 3 mol% and less than or equal to 8 mol%, greater than or equal to 3 mol% and less than or equal to 7 mol%, greater than or equal to 3.5 mol% and less than or equal to 9 mol%, greater than or equal to 3.5 mol% and less than or equal to 8 mol%, greater than or equal to 3.5 mol% and less than or equal to 7 mol%, greater than or equal to 4 mol% and less than or equal to 9 mol%, greater than or equal to 4 mol% and less than or equal to 8 mol%, greater than or equal to 4 mol% and less than or equal to 7 mol%, greater than or equal to 4.5 mol% and less than or equal to 9 mol%, greater than or equal to 4.5 mol% and less than or equal to 8 mol%, or even greater than or equal to 4.5 mol% and less than or equal to 7 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of ZrO2.

[0131] The glass compositions and resultant glass articles described herein may includeY2O3 to increase the refractive index of the glass compositions and the resultant glass articles and minimize the concentration of other high refractive index oxides that would otherwise increase the density. Y2O3 can also function to increase stability of the glass in relatively low concentrations (e.g. less than or equal to 3 mol%). However, Y2O3 in relatively high concentrations (e.g. above 3 mol%) can be detrimental to glass stability and can lead to devitrification. In embodiments, the glass composition and the resultant glass article may comprise greater than 0 mol% and less than or equal to 3 mol% Y2O3. In embodiments, the concentration of Y2O3in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol%, or even greater than or equal to 1 mol%. In embodiments, the concentration of Y2O3in the glass composition and the resultant glass article may be less than or equal to 3 mol%, less than or equal to 2.5 mol%, or even less than or equal to 2 mol%. In embodiments, the concentration of Y2O3 in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 3 mol%, greater than or equal to 0 mol% and less than or equal to 2.5 mol%, greater than or equal to 0 mol% and less than or equal to 2 mol%, greater than or equal to 0.1 mol% and less than or equal to 3 mol%, greater than or equal to 0.1 mol% and less than or equal to 2.5 mol%, greater than or equal to 0.1 mol% and less than or equal to 2 mol%, greater than or equal to 0.5 mol% and less than or equal to 3 mol%, greater than or equal to 0.5 mol% and less than or equal to 2.5 mol%, greater than or equal to 0.5 mol% and less than or equal to 2 mol%, greater than or equal to 1 mol% and less than or equal to 3 mol%, greater than or equal to 1 mol% and less than or equal to 2.5 mol%, or even greater than or equal to 1 mol% and less than or equal to 2 mol%, or any and all sub-ranges formed from anyAttorney Docket No. SP23-366PCT of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of Y2O3.

[0132] The glass compositions and resultant glass articles described herein may includeTa2O5 to increase the refractive index and improve the mechanical properties of the glass compositions and the resultant glass articles. However, Ta2O5in relatively high concentrations (e.g., greater than 4.5 mol%) can significantly increase the density of the glass composition and resultant glass article, diminishing ion exchangeability. Additionally, the cost of Ta2O5is often prohibitive, making it undesirable for many commercial applications. In embodiments, the glass composition and the resultant glass article may comprise greater than 0 mol% and less than or equal to 4.5 mol% Ta2O5. In embodiments, the concentration of Ta2O5 in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol%, or even greater than or equal to 1 mol%. In embodiments, the concentration of Ta2O5 in the glass composition and the resultant glass article may be less than or equal to 4.5 mol%, less than or equal to 4 mol%, or even less than or equal to 3.5 mol%. In embodiments, the concentration of Ta2O5 in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 4.5 mol%, greater than or equal to 0 mol% and less than or equal to 4 mol%, greater than or equal to 0 mol% and less than or equal to 3.5 mol%, greater than or equal to 0.1 mol% and less than or equal to 4.5 mol%, greater than or equal to 0.1 mol% and less than or equal to 4 mol%, greater than or equal to 0.1 mol% and less than or equal to 3.5 mol%, greater than or equal to 0.5 mol% and less than or equal to 4.5 mol%, greater than or equal to 0.5 mol% and less than or equal to 4 mol%, greater than or equal to 0.5 mol% and less than or equal to 3.5 mol%, greater than or equal to 1 mol% and less than or equal to 4.5 mol%, greater than or equal to 1 mol% and less than or equal to 4 mol%, or even greater than or equal to 1 mol% and less than or equal to 3.5 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of Ta2O5.

[0133] Additionally, the total sum of the high refractive index oxides (i.e., TiO2 (mol%) +La2O3 (mol%) + Nb2O5 (mol%) + ZrO2 (mol%) + Y2O3 (mol%) + Ta2O5 (mol%)) within the glass composition and resultant glass article can effect the refractive index of the glass composition and the resultant glass article. Where the sum of these high refractive index oxides is too low (e.g., less than 27 mol%), the overall refractive index of the glass composition andAttorney Docket No. SP23-366PCT resultant glass article may be undesireably low (e.g., less than or equal to 1.795 as measured at 589 nm). However, where the sum of these high refractive index oxides is too high (e.g., greater than 50 mol%), the density of the glass composition and resultant glass article may become too high (e.g., greater than or equal to 3.95 g / cm3), reducing the ion exchangeability of the glass. The sum of the high refractive index oxides in the glass composition and the resultant glass article may be greater than or equal to 27 mol%. In embodiments, the sum of the high refractive index oxides in the glass composition and the resultant glass article may be greater than or equal to 27 mol%, greater than or equal to 29 mol%, greater than or equal to 31 mol%, greater than or equal to 33 mol%, or even greater than or equal to 35 mol%. In embodiments, the sum of the high refractive index oxides may be less than or equal to 50 mol%, less than or equal to 45 mol%, or event less than or equal to 40 mol%. In embodiments, the sum of the high refractive index oxides in the glass composition and the resultant glass article may be greater than or equal to 27 mol% and less than or equal to 50 mol%, greater than or equal to 27 mol% and less than or equal to 45 mol%, greater than or equal to 27 mol% and less than or equal to 40 mol%, greater than or equal to 29 mol% and less than or equal to 50 mol%, greater than or equal to 29 mol% and less than or equal to 45 mol%, greater than or equal to 29 mol% and less than or equal to 40 mol%, greater than or equal to 31 mol% and less than or equal to 50 mol%, greater than or equal to 31 mol% and less than or equal to 45 mol%, greater than or equal to 31 mol% and less than or equal to 40 mol%, greater than or equal to 33 mol% and less than or equal to 50 mol%, greater than or equal to 33 mol% and less than or equal to 45 mol%, greater than or equal to 33 mol% and less than or equal to 40 mol%, greater than or equal to 35 mol% and less than or equal to 50 mol%, greater than or equal to 35 mol% and less than or equal to 45 mol%, or even greater than or equal to 35 mol% and less than or equal to 40 mol%, or any and all sub-ranges formed from any of these endpoints.

[0134] The glass compositions described hereinabove may also include B2O3. The inclusionof B2O3 increases the mechanical properties of the glass composition and the resultant glass article, particularly the fracture toughness of the glass. Additionally, B2O3 may be added to improve the stability of the glass network structure. However, adding too much B2O3(e.g., greater than 12 mol%) to the glass composition or the resultant glass article can minimize the amount of compressive stress imparted in an ion exchange process decreasing the effects of chemical strengthening. The glass composition and the resultant glass article may comprise greater than or equal to 0 mol% and less than or equal to 12 mol% B2O3. In embodiments, theconcentration of B2O3in the glass composition and the resultant glass article may be greaterAttorney Docket No. SP23-366PCT than or equal to 0 mol%, greater than or equal to 1 mol%, greater than or equal to 2 mol%, greater than or equal to 3 mol%, greater than or equal to 4 mol%, or even greater than or equal to 5 mol%. In embodiments, the concentration of B2O3 in the glass composition and the resultant glass article may be less than or equal to 12 mol%, less than or equal to 10 mol%, or even less than or equal to 8 mol%. In embodiments, the concentration of B2O3in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 12 mol%, greater than or equal to 0 mol% and less than or equal to 10 mol%, greater than or equal to 0 mol% and less than or equal to 8 mol%, greater than or equal to 1 mol% and less than or equal to 12 mol%, greater than or equal to 1 mol% and less than or equal to 10 mol%, greater than or equal to 1 mol% and less than or equal to 8 mol%, greater than or equal to 2 mol% and less than or equal to 12 mol%, greater than or equal to 2 mol% and less than or equal to 10 mol%, greater than or equal to 2 mol% and less than or equal to 8 mol%, greater than or equal to 3 mol% and less than or equal to 12 mol%, greater than or equal to 3 mol% and less than or equal to 10 mol%, greater than or equal to 3 mol% and less than or equal to 8 mol%, greater than or equal to 4 mol% and less than or equal to 12 mol%, greater than or equal to 4 mol% and less than or equal to 10 mol%, greater than or equal to 4 mol% and less than or equal to 8 mol, greater than or equal to 5 mol% and less than or equal to 12 mol%, greater than or equal to 5 mol% and less than or equal to 10 mol%, or even greater than or equal to 5 mol% and less than or equal to 8 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of B2O3.

[0135] In embodiments, the glass compositions and the resultant glass articles may containalkaline earth oxides and transition metal oxides, such as BaO, SrO, CaO, and ZnO.

[0136] The glass compositions described herein may include BaO. BaO may lower theviscosity of a glass, which may enhance the formability of the glass composition and resultant glass article. Additionally, BaO also may increase the refractive index of the glass. However, BaO at relatively high concentrations (e.g., greater than 5 mol%) may increase the density and the coefficient of thermal expansion (CTE) of the glass composition, decreasing the ion exchangeability of the glass. In embodiments, the glass compositions and the resultant glass articles may comprise greater than or equal to 0 mol% and less than or equal to 5 mol% BaO. In embodiments, the concentration of BaO in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater thanAttorney Docket No. SP23-366PCT or equal to 0.5 mol% or even greater than or equal to 1 mol%. In embodiments, the concentration of BaO in the glass composition and the resultant glass article may be less than or equal to 5 mol%, less than or equal to 4 mol% or even less than or equal to 3 mol%. In embodiments, the concentration of BaO in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0 mol% and less than or equal to 4 mol%, greater than or equal to 0 mol% and less than or equal to 3 mol%, greater than or equal to 0.1 mol% and less than or equal to 5 mol%, greater than or equal to 0.1 mol% and less than or equal to 4 mol%, greater than or equal to 0.1 mol% and less than or equal to 3 mol%, greater than or equal to 1 mol% and less than or equal to 5 mol%, greater than or equal to 1 mol% and less than or equal to 4 mol%, or even greater than or equal to 1 mol% and less than or equal to 3 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of BaO.

[0137] The glass compositions described herein may include SrO. SrO may lower theviscosity of a glass, which may enhance the formability of the glass composition and resultant glass article. Additionally, SrO also may increase the refractive index of the glass. However, SrO at relatively high concentrations (e.g., greater than 5 mol%) may significantly increase the density and the CTE of the glass composition, decreasing the ion exchangeability of the glass. In embodiments, the glass compositions and the resultant glass articles may comprise greater than or equal to 0 mol% and less than or equal to 5 mol% SrO. In embodiments, the concentration of SrO in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol% or even greater than or equal to 1 mol%. In embodiments, the concentration of SrO in the glass composition and the resultant glass article may be less than or equal to 5 mol%, less than or equal to 4 mol% or even less than or equal to 3 mol%. In embodiments, the concentration of SrO in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0 mol% and less than or equal to 4 mol%, greater than or equal to 0 mol% and less than or equal to 3 mol%, greater than or equal to 0.1 mol% and less than or equal to 5 mol%, greater than or equal to 0.1 mol% and less than or equal to 4 mol%, greater than or equal to 0.1 mol% and less than or equal to 3 mol%, greater than or equal to 1 mol% and less than or equal to 5 mol%, greater than or equal to 1 mol% and less than or equal to 4 mol%, or even greater than or equal to 1 mol% and less than or equal to 3 mol%, or any and all sub-ranges formed from any of these endpoints. InAttorney Docket No. SP23-366PCT embodiments, the glass composition and the resultant glass article may be free or substantially free of SrO.

[0138] The glass compositions described herein may include ZnO. ZnO may lower theviscosity of a glass, which may enhance the formability of the glass composition and resultant glass article. However, ZnO at relatively high concentrations (e.g., greater than 5 mol%) may significantly increase the density and the CTE of the glass composition, decreasing the ion exchangeability of the glass. In embodiments, the glass compositions and the resultant glass articles may comprise greater than or equal to 0 mol% and less than or equal to 5 mol% ZnO. In embodiments, the concentration of ZnO in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol% or even greater than or equal to 1 mol%. In embodiments, the concentration of ZnO in the glass composition and the resultant glass article may be less than or equal to 5 mol%, less than or equal to 4 mol% or even less than or equal to 3 mol%. In embodiments, the concentration of ZnO in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0 mol% and less than or equal to 4 mol%, greater than or equal to 0 mol% and less than or equal to 3 mol%, greater than or equal to 0.1 mol% and less than or equal to 5 mol%, greater than or equal to 0.1 mol% and less than or equal to 4 mol%, greater than or equal to 0.1 mol% and less than or equal to 3 mol%, greater than or equal to 1 mol% and less than or equal to 5 mol%, greater than or equal to 1 mol% and less than or equal to 4 mol%, or even greater than or equal to 1 mol% and less than or equal to 3 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of ZnO.

[0139] The glass compositions described herein may include CaO. CaO may lower theviscosity of a glass, which may enhance the formability of the glass composition and resultant glass article. However, CaO at relatively high concentrations (e.g., greater than 5 mol%) may significantly increase the density and the CTE of the glass composition, decreasing the ion exchangeability of the glass. In embodiments, the glass compositions and the resultant glass articles may comprise greater than or equal to 0 mol% and less than or equal to 5 mol% CaO. In embodiments, the concentration of CaO in the glass composition and the resultant glass article may be greater than or equal to 0 mol%, greater than or equal to 0.1 mol%, greater than or equal to 0.5 mol% or even greater than or equal to 1 mol%. In embodiments, theAttorney Docket No. SP23-366PCT concentration of CaO in the glass composition and the resultant glass article may be less than or equal to 5 mol%, less than or equal to 4 mol% or even less than or equal to 3 mol%. In embodiments, the concentration of CaO in the glass composition and the resultant glass article may be greater than or equal to 0 mol% and less than or equal to 5 mol%, greater than or equal to 0 mol% and less than or equal to 4 mol%, greater than or equal to 0 mol% and less than or equal to 3 mol%, greater than or equal to 0.1 mol% and less than or equal to 5 mol%, greater than or equal to 0.1 mol% and less than or equal to 4 mol%, greater than or equal to 0.1 mol% and less than or equal to 3 mol%, greater than or equal to 1 mol% and less than or equal to 5 mol%, greater than or equal to 1 mol% and less than or equal to 4 mol%, or even greater than or equal to 1 mol% and less than or equal to 3 mol%, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass composition and the resultant glass article may be free or substantially free of CaO.

[0140] In embodiments, the glass compositions and the resultant glass articles describedherein can comprise a colorant. The colorant can be formulated to impart a preselected color (e.g., any one or more of any of preselected hue {e.g., shades of red, orange, yellow, green, blue, and violet}, preselected saturation, preselected brightness, and / or preselected gloss) to a glass article is added to a glass composition. A colorant can include one or more metal containing dopants in amounts formulated to impart such preselected color. In embodiments, such one or more metal containing dopants can include one or more transition metals, one or more rare earth metals, or one or more transition metals and one or more rare earth metals. In embodiments, such one or more metal containing dopants can include one or more of one or more of Au, Ag, Cu, Ni, Co, Fe, Mn, Cr, V, Ti, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu; while in still other aspects, such one or more metal containing dopants can include one or more of Au, Ag, Cu, Ni, Co, Fe, Mn, Cr, and V. It will be appreciated that metal containing dopants might be in the form of an element (e.g., Au, Ag ...etc.) and / or a compound (e.g., CuO, V2O5, Cr2O3, Co3O4, Fe2O3... etc.). Also, such metal containing dopants are added in amounts formulated to impart a preselected color. Such amounts might be up to 5 mol % and more in any combination of dopants that imparts the preselect color.

[0141] In embodiments, the glass compositions and the resultant glass articles describedherein are free or substantially free of P (i.e., P2O5). When the glass composition contains P2O5, the glass stability may be compromised due to devitrification, thereby reducing the optical transparency of the glass.Attorney Docket No. SP23-366PCT

[0142] The articles formed from the glass compositions described herein may be any suitableshape or thickness, which may vary depending on the particular application for use of the glass composition. As seen in FIG.5, a glass article 100 may comprise a first major surface 110, a second major surface 112, and a thickness t measured between the first major surface 110 and the second major surface 112.

[0143] In embodiments, the glass article may have a thickness greater than or equal to 30µm, greater than or equal to 50 µm, greater than or equal to 100 µm, greater than or equal to 250 µm, greater than or equal to 500 µm, greater than or equal to 750 µm, or even greater than or equal to 1 mm. In embodiments, the glass article may have a thickness less than or equal to 6 mm, less than or equal to 5 mm, less than or equal to 4 mm, less than or equal to 3 mm, or even less than or equal to 2 mm. In embodiments, the glass article may have a thickness greater than or equal to 30 µm and less than or equal to 6 mm, greater than or equal to 30 µm and less than or equal to 5 mm, greater than or equal to 30 µm and less than or equal to 4 mm, greater than or equal to 30 µm and less than or equal to 3 mm, greater than or equal to 30 µm and less than or equal to 2 mm, greater than or equal to 50 µm and less than or equal to 6 mm, greater than or equal to 50 µm and less than or equal to 5 mm, greater than or equal to 50 µm and less than or equal to 4 mm, greater than or equal to 50 µm and less than or equal to 3 mm, greater than or equal to 50 µm and less than or equal to 2 mm, greater than or equal to 100 µm and less than or equal to 6 mm, greater than or equal to 100 µm and less than or equal to 5 mm, greater than or equal to 100 µm and less than or equal to 4 mm, greater than or equal to 100 µm and less than or equal to 3 mm, greater than or equal to 100 µm and less than or equal to 2 mm, greater than or equal to 250 µm and less than or equal to 6 mm, greater than or equal to 250 µm and less than or equal to 5 mm, greater than or equal to 250 µm and less than or equal to 4 mm, greater than or equal to 250 µm and less than or equal to 3 mm, greater than or equal to 250 µm and less than or equal to 2 mm, greater than or equal to 500 µm and less than or equal to 6 mm, greater than or equal to 500 µm and less than or equal to 5 mm, greater than or equal to 500 µm and less than or equal to 4 mm, greater than or equal to 500 µm and less than or equal to 3 mm, greater than or equal to 500 µm and less than or equal to 2 mm, greater than or equal to 750 µm and less than or equal to 6 mm, greater than or equal to 750 µm and less than or equal to 5 mm, greater than or equal to 750 µm and less than or equal to 4 mm, greater than or equal to 750 µm and less than or equal to 3 mm, greater than or equal to 750 µm and less than or equal to 2 mm, greater than or equal to 1 mm and less than or equal to 6 mm, greater than or equal to 1 mm and less than or equal to 5 mm, greater than or equal to 1 mm and lessAttorney Docket No. SP23-366PCT than or equal to 4 mm, greater than or equal to 1 mm and less than or equal to 3 mm, or even greater than or equal to 1 mm and less than or equal to 2 mm, or any and all sub-ranges formed from any of these endpoints.

[0144] In embodiments, the glass composition and the resultant glass article may have adensity greater than or equal to 3.25 g / cm3, greater than or equal to 3.50 g / cm3, or even greater than or equal to 3.60 g / cm3. In embodiments, the glass composition and the resultant glass article may have a density less than or equal to 3.95 g / cm3, less than or equal to 3.90 g / cm3, less than or equal to 3.85 g / cm3, or even less than or equal to 3.80 g / cm3. In embodiments, the glass composition and the resultant glass article may have a density greater than or equal to 3.25 g / cm3and less than or equal to 3.95 g / cm3, greater than or equal to 3.25 g / cm3and less than or equal to 3.90 g / cm3, greater than or equal to 3.25 g / cm3and less than or equal to 3.85 g / cm3, greater than or equal to 3.25 g / cm3and less than or equal to 3.80 g / cm3, greater than or equal to 3.50 g / cm3and less than or equal to 3.95 g / cm3, greater than or equal to 3.50 g / cm3 and less than or equal to 3.90 g / cm3, greater than or equal to 3.50 g / cm3and less than or equal to 3.85 g / cm3, greater than or equal to 3.50 g / cm3and less than or equal to 3.80 g / cm3, greater than or equal to 3.60 g / cm3and less than or equal to 3.95 g / cm3, greater than or equal to 3.60 g / cm3and less than or equal to 3.90 g / cm3, greater than or equal to 3.60 g / cm3and less than or equal to 3.85 g / cm3, or even greater than or equal to 3.60 g / cm3and less than or equal to 3.80 g / cm3, or any and all sub-ranges formed from any of these endpoints.

[0145] In embodiments, the glass composition and the resultant glass article may have arefractive index (nd) greater than or equal to 1.75, greater than or equal to 1.8, greater than or equal to 1.82, or even greater than or equal to 1.85. In embodiments, the glass composition and the resultant glass article may have a refractive index less than or equal to 2.0 or even less than or equal to 1.95. In embodiments, the glass composition and the resultant glass article may have a refractive index greater than or equal to 1.75 and less than or equal to 2.0, greater than or equal to 1.75 and less than or equal to 1.95, greater than or equal to 1.8 and less than or equal to 2.0, greater than or equal to 1.8 and less than or equal to 1.95, greater than or equal to 1.82 and less than or equal to 2.0, greater than or equal to 1.82 and less than or equal to 1.95, greater than or equal to 1.85 and less than or equal to 2.0, or even greater than or equal to 1.85 and less than or equal to 1.95, or any and all sub-ranges formed from any of these endpoints.

[0146] In embodiments, the glass compositions and resultant glass articles may be subjectedto chemical strengthening methods. Specifically, the glass articles described herein are ionAttorney Docket No. SP23-366PCT exchangeable to facilitate strengthening the glass article made from the glass compositions. In typical ion exchange processes, smaller metal ions in the glass article are replaced or “exchanged” with larger metal ions of the same valence within a layer that is close to the outer surface of the glass article. The replacement of smaller ions with larger ions creates a compressive stress within the layer of the glass article. In embodiments, the metal ions are monovalent metal ions (i.e., Na+, K+, and the like), and ion exchange is accomplished by immersing the glass article in an ion exchange bath comprising at least one molten salt of the larger metal ion that is to replace the smaller metal ion in the glass article. Alternatively, other monovalent ions such as Ag+, Tl+, Cu+, and the like may be exchanged for monovalent ions. The ion exchange process or processes that are used to strengthen the glass article may include, but are not limited to, immersion in a single bath or multiple baths of like or different compositions with washing and / or annealing steps between immersions. In embodiments, there may be a first ion exchange step and a second ion exchange step. “Ion exchange” and “chemical strengthening” are used interchangeably throughout.

[0147] The glass article, according to embodiments, may be exposed to an ion exchange bathat a temperature greater than or equal to 380 °C and less than or equal to 585 °C, greater than or equal to 400 °C and less than or equal to 570 °C, greater than or equal to 415 °C and less than or equal to 555 °C, greater than or equal to 435 °C and less than or equal to 540 °C, greater than or equal to 450 °C and less than or equal to 530 °C, greater than or equal to 465 °C and less than or equal to 520 °C, or even greater than or equal to 485 °C and less than or equal to 510 °C, or any and all sub-ranges between the foregoing values.

[0148] In embodiments, the glass article may be exposed to the ion exchange bath for aduration greater than or equal to 0.25 hours and less than or equal to 32 hours, greater than or equal to 0.25 hours and less than or equal to 28 hours, greater than or equal to 0.25 hours and less than or equal to 24 hours, greater than or equal to 0.25 hours and less than or equal to 20 hours, greater than or equal to 0.25 hours and less than or equal to 16 hours, greater than or equal to 1 hour and less than or equal to 32 hours, greater than or equal to 1 hour and less than or equal to 28 hours, greater than or equal to 1 hour and less than or equal to 24 hours, greater than or equal to 1 hour and less than or equal to 20 hours, greater than or equal to 1 hour and less than or equal to 16 hours, greater than or equal to 4 hours and less than or equal to 32 hours, greater than or equal to 4 hours and less than or equal to 28 hours, or even greater than or equal to 4 hours and less than or equal to 24 hours, greater than or equal to 4 hours and lessAttorney Docket No. SP23-366PCT than or equal to 20 hours, or any and all sub-ranges formed from any of these endpoints. In embodiments, the glass article may be exposed to the second ion exchange solution after exposure to an initial ion exchange solution (in a multi-step ion exchange process) for a duration greater than or equal to 0.05 hour and less than or equal to 32 hours, greater than or equal to 0.05 hour and less than or equal to 24 hours, greater than or equal to 0.05 hour and less than or equal to 18 hours, greater than or equal to 0.05 hour and less than or equal to 12 hours, greater than or equal to 0.05 hour and less than or equal to 6 hours, greater than or equal to 0.05 hour and less than or equal to 2 hours, greater than or equal to 0.1 hour and less than or equal to 32 hours, greater than or equal to 0.1 hour and less than or equal to 24 hours, greater than or equal to 0.1 hour and less than or equal to 18 hours, greater than or equal to 0.1 hour and less than or equal to 12 hours, greater than or equal to 0.1 hour and less than or equal to 6 hours, greater than or equal to 0.1 hour and less than or equal to 2 hours, greater than or equal to 0.5 hour and less than or equal to 32 hours, greater than or equal to 0.5 hour and less than or equal to 24 hours, greater than or equal to 0.5 hour and less than or equal to 18 hours, greater than or equal to 0.5 hour and less than or equal to 12 hours, greater than or equal to 0.5 hour and less than or equal to 6 hours, greater than or equal to 0.5 hour and less than or equal to 2 hours, greater than or equal to 1 hour and less than or equal to 32 hours, greater than or equal to 1 hour and less than or equal to 24 hours, greater than or equal to 1 hour and less than or equal to 18 hours, greater than or equal to 1 hour and less than or equal to 12 hours, greater than or equal to 1 hour and less than or equal to 6 hours, or even greater than or equal to 1 hour and less than or equal to 2 hours, or any and all sub-ranges formed from any of these endpoints.

[0149] In embodiments, the ion exchange bath may comprise KNO3, NaNO3, orcombinations thereof. While not wishing to be bound by theory, an ion exchange bath may be maintained at relatively lower temperatures (e.g., lower than the glass Tg) in order to prevent stress relaxation in the glass and to achieve higher surface compressive stresses in the glass article.

[0150] Referring back to FIG. 5, the glass article 100 has a first region under compressivestress (e.g., first and second compressive layers 120, 122 in FIG.5) extending from the surface to a depth of compression (DOC) (e.g., d1, d2 in FIG.5) of the glass article and a second region (e.g., central region 132 in FIG.5) under a tensile stress or central tension (CT) extending from the DOC into the central or interior region of the glass article.Attorney Docket No. SP23-366PCT

[0151] In embodiments, a glass article made from the glass composition may have a surfacecompressive stress (CS), after ion exchange strengthening, greater than or equal to 200 MPa. In embodiments, a glass article made from the glass composition may have a surface compressive stress, after ion exchange strengthening, greater than or equal to 200 MPa, greater than or equal to 230 MPa, greater than or equal to 230 MPa, greater than or equal to 250 MPa, greater than or equal to 300 MPa, greater than or equal to 350 MPa, greater than or equal to 400 MPa, greater than or equal to 450 MPa, or even greater than or equal to 500 MPa. In embodiments, a glass article made from the glass composition may have a surface compressive stress, after ion exchange strengthening, less than or equal to 900 MPa, less than or equal to 800 MPa, or even less than or equal to 700 MPa. In embodiments, a glass article made from the glass composition may have a surface compressive stress, after ion exchange strengthening, greater than or equal to 200 MPa and less than or equal to 900 MPa, greater than or equal to 200 MPa and less than or equal to 800 MPa, greater than or equal to 200 MPa and less than or equal to 700 MPa, greater than or equal to 230 MPa and less than or equal to 900 MPa, greater than or equal to 230 MPa and less than or equal to 800 MPa, greater than or equal to 230 MPa and less than or equal to 700 MPa, greater than or equal to 250 MPa and less than or equal to 900 MPa, greater than or equal to 250 MPa and less than or equal to 800 MPa, greater than or equal to 250 MPa and less than or equal to 700 MPa, greater than or equal to 300 MPa and less than or equal to 900 MPa, greater than or equal to 300 MPa and less than or equal to 800 MPa, greater than or equal to 300 MPa and less than or equal to 700 MPa, greater than or equal to 350 MPa and less than or equal to 900 MPa, greater than or equal to 350 MPa and less than or equal to 800 MPa, greater than or equal to 350 MPa and less than or equal to 700 MPa, greater than or equal to 400 MPa and less than or equal to 900 MPa, greater than or equal to 400 MPa and less than or equal to 800 MPa, greater than or equal to 400 MPa and less than or equal to 700 MPa, greater than or equal to 450 MPa and less than or equal to 900 MPa, greater than or equal to 450 MPa and less than or equal to 800 MPa, greater than or equal to 450 MPa and less than or equal to 700 MPa, greater than or equal to 500 MPa and less than or equal to 900 MPa, greater than or equal to 500 MPa and less than or equal to 800 MPa, or even greater than or equal to 500 MPa and less than or equal to 700 MPa, or any and all sub-ranges formed from any of these endpoints.

[0152] In embodiments, a glass article made from the glass composition may have a centraltension (CT), after ion exchange strengthening, greater than or equal to 35 MPa, as measured at an article thickness of 1 mm. In embodiments, a glass article made from the glassAttorney Docket No. SP23-366PCT composition may have a central tension, after ion exchange strengthening, greater than or equal to 35 MPa, greater than or equal to 40 MPa, greater than or equal to 45 MPa, or even greater than or equal to 50 MPa, as measured at an article thickness of 1 mm. In embodiments, a glass article made from the glass composition may have a central tension, after ion exchange strengthening, less than or equal to 150 MPa, less than or equal to 100 MPa or even less than or equal to 90 MPa, as measured at an article thickness of 1 mm. In embodiments, a glass article made from the glass composition may have a central tension after ion exchange strengthening greater than or equal to 35 MPa and less than or equal to 150 MPa, greater than or equal to 35 MPa and less than or equal to 100 MPa, greater than or equal to 35 MPa and less than or equal to 90 MPa, greater than or equal to 40 MPa and less than or equal to 150 MPa, greater than or equal to 40 MPa and less than or equal to 100 MPa, greater than or equal to 40 MPa and less than or equal to 90 MPa, greater than or equal to 45 MPa and less than or equal to 150 MPa, greater than or equal to 45 MPa and less than or equal to 100 MPa, greater than or equal to 45 MPa and less than or equal to 90 MPa, greater than or equal to 50 MPa and less than or equal to 150 MPa, greater than or equal to 50 MPa and less than or equal to 100 MPa, or even greater than or equal to 50 MPa and less than or equal to 90 MPa, or any and all sub- ranges formed from any of these endpoints, as measured at an article thickness of 1 mm.

[0153] In embodiments, a chemically strengthened glass article made from the glasscomposition may have a modulus of rupture (MOR) that is 2 times greater than the glass article’s MOR prior to chemical strengthening. In embodiments, a chemically strengthened glass article may exhibit an MOR value relative to the MOR of an unstrengthened glass article that is larger by a factor of 1.5, 2, 2.5, 3, 3.5, 4, 4.5, or even 5. In embodiments, a glass article made from the glass composition may have an MOR after ion exchange strengthening greater than or equal to 600 MPa, as measured at an article thickness of 1 mm. In embodiments, a glass article made from the glass composition may have a modulus of rupture, after chemical strengthening, greater than or equal to 400 MPa, greater than or equal to 450 MPa, greater than or equal to 500 MPa, greater than or equal to 550 MPa, greater than or equal to 600 MPa, greater than or equal to 650 MPa, greater than or equal to 700 MPa, greater than or equal to 750 MPa, greater than or equal to 800 MPa, greater than or equal to 850 MPa, greater than or equal to 900 MPa, greater than or equal to 950 MPa, or even greater than or equal to 1000 MPa. In embodiments, a glass article made from the glass composition may have a surface compressive stress, after ion exchange strengthening, less than or equal to 1400 MPa, less than or equal to 1200 MPa, or even less than or equal to 1100 MPa. In embodiments, a glass articleAttorney Docket No. SP23-366PCT made from the glass composition may have a surface compressive stress, after ion exchange strengthening, greater than or equal to 400 MPa and less than or equal to 1400 MPa, greater than or equal to 400 MPa and less than or equal to 1200 MPa, greater than or equal to 400 MPa and less than or equal to 1100 MPa, greater than or equal to 450 MPa and less than or equal to 1400 MPa, greater than or equal to 450 MPa and less than or equal to 1200 MPa, greater than or equal to 450 MPa and less than or equal to 1100 MPa, greater than or equal to 500 MPa and less than or equal to 1400 MPa, greater than or equal to 500 MPa and less than or equal to 1200 MPa, greater than or equal to 500 MPa and less than or equal to 1100 MPa, greater than or equal to 550 MPa and less than or equal to 1400 MPa, greater than or equal to 550 MPa and less than or equal to 1200 MPa, greater than or equal to 550 MPa and less than or equal to 1100 MPa, greater than or equal to 600 MPa and less than or equal to 1400 MPa, greater than or equal to 600 MPa and less than or equal to 1200 MPa, greater than or equal to 600 MPa and less than or equal to 1100 MPa, greater than or equal to 650 MPa and less than or equal to 1400 MPa, greater than or equal to 650 MPa and less than or equal to 1200 MPa, greater than or equal to 650 MPa and less than or equal to 1100 MPa, greater than or equal to 700 MPa and less than or equal to 1400 MPa, greater than or equal to 700 MPa and less than or equal to 1200 MPa, greater than or equal to 700 MPa and less than or equal to 1100 MPa, greater than or equal to 750 MPa and less than or equal to 1400 MPa, greater than or equal to 750 MPa and less than or equal to 1200 MPa, greater than or equal to 750 MPa and less than or equal to 1100 MPa, greater than or equal to 800 MPa and less than or equal to 1400 MPa, greater than or equal to 800 MPa and less than or equal to 1200 MPa, greater than or equal to 800 MPa and less than or equal to 1100 MPa, greater than or equal to 850 MPa and less than or equal to 1400 MPa, greater than or equal to 850 MPa and less than or equal to 1200 MPa, greater than or equal to 850 MPa and less than or equal to 1100 MPa, greater than or equal to 900 MPa and less than or equal to 1400 MPa, greater than or equal to 900 MPa and less than or equal to 1200 MPa, greater than or equal to 900 MPa and less than or equal to 1100 MPa, greater than or equal to 950 MPa and less than or equal to 1400 MPa, greater than or equal to 950 MPa and less than or equal to 1200 MPa, greater than or equal to 950 MPa and less than or equal to 1100 MPa, greater than or equal to 1000 MPa and less than or equal to 1400 MPa, greater than or equal to 1000 MPa and less than or equal to 1200 MPa, or even greater than or equal to 1000 MPa and less than or equal to 1100 MPa, or any and all sub-ranges formed from any of these endpoints.Attorney Docket No. SP23-366PCT

[0154] In embodiments, a glass article made from the glass composition may have arelatively low frangibility after ion exchange, as measured by the Tip Method discussed herein, wherein the glass articles had a thickness of 1 mm and were chemically strengthened in an ion exchange bath comprising 100% NaNO3 at a temperature of 430°C for 6 hours and 45 minutes. In embodiments, a glass article, after chemical strengthening, may break into less than or equal to 100 pieces (pieces may alternatively be referred to as fragments). In embodiments, a glass article, after chemical strengthening, may break into greater than or equal to 2 pieces, greater than or equal to 5 pieces, greater than or equal to 5 pieces, greater than or equal to 10 pieces, or even greater than or equal to 20 pieces. In embodiments, a glass article, after chemical strengthening, may break into less than or equal to 100 pieces, less than or equal to 70 pieces, less than or equal to 65 pieces, or even less than or equal to 50 pieces. In embodiments a glass article, after chemical strengthening, may break into greater than or equal to 2 pieces and less than or equal to 100 pieces, greater than or equal to 2 pieces and less than or equal to 70 pieces, greater than or equal to 2 pieces and less than or equal to 65 pieces, greater than or equal to 2 pieces and less than or equal to 50 pieces, greater than or equal to 5 pieces and less than or equal to 100 pieces, greater than or equal to 5 pieces and less than or equal to 70 pieces, greater than or equal to 5 pieces and less than or equal to 65 pieces, greater than or equal to 5 pieces and less than or equal to 50 pieces, greater than or equal to 10 pieces and less than or equal to 100 pieces, greater than or equal to 10 pieces and less than or equal to 70 pieces, greater than or equal to 10 pieces and less than or equal to 65 pieces, greater than or equal to 10 pieces and less than or equal to 50 pieces, greater than or equal to 20 pieces and less than or equal to 100 pieces, greater than or equal to 20 pieces and less than or equal to 70 pieces, greater than or equal to 20 pieces and less than or equal to 65 pieces, or even greater than or equal to 20 pieces and less than or equal to 50 pieces, or any and all sub-ranges formed from any of these endpoints.

[0155] The glass compositions and resultant glass articles disclosed herein may beincorporated into another article such as a display (or display articles) (e.g., consumer electronics, including mobile phones, tablets, computers, navigation systems, augmented reality systems, and the like), architectural articles, transportation articles (e.g., automobiles, trains, aircraft, sea craft, etc.), appliance articles, or any article that requires some transparency, scratch-resistance, abrasion resistance or a combination thereof. An exemplary article incorporating any of the glass articles disclosed herein is shown in FIGs. 6A and 6B. Specifically, FIGs.6A and 6B show a consumer electronic device 200 including a housing 202Attorney Docket No. SP23-366PCT having front 204, back 206, and side surfaces 208; electrical components (not shown) that are at least partially inside or entirely within the housing and including at least a controller, a memory, and a display 210 at or adjacent to the front surface of the housing; and a cover 212 at or over the front surface of the housing such that it is over the display. In embodiments, at least a portion of at least one of the cover 212 and the housing 202 may include any of the glass articles described herein. In embodiments, the glass articles disclosed herein are lenses. Examples

[0156] In order that various embodiments be more readily understood, reference is made tothe following examples, which are intended to illustrate various embodiments of the glass compositions and glass articles described herein.

[0157] The glass articles were formed by melting between 200 - 1000g of raw materials,according to the compositions listed below, in a platinum crucible. To achieve a uniform melt of the glass compositions, the crucible was placed in an electric furnace at temperatures between 1350 - 1450°C for 3 hours. The melted glass compositions were then poured on a cold surface to cool and form uniform glass sheets. The resulting glass sheets had a standard thickness of approximately 4 to 6 mm and glass transition temperatures between 530°C to 580°C. The resulting glass sheets were then annealed for 1 hour at temperatures just below their glass transition temperature to produce glass articles.

[0158] Table 1 shows example glass compositions (in terms of mol%) and the respectiveproperties of the glass compositions. Glass articles were formed having the example glass compositions E1-E24.Attorney Docket No. SP23-366PCT

[0159] Table 1Attorney Docket No. SP23-366PCT

[0160] Table 1 (continued)Attorney Docket No. SP23-366PCT

[0161] Table 1 (continued)E17 E18 E19 E20 E21 E22 E23 E2441.18 39.18 41.18 38.18 40.18 39.68 33.40 34.003.32 3.32 3.32 6.32 3.32 3.32 - -3.00 3.00 3.00 3.00 4.00 4.50 2.00 2.0022.93 22.93 16.93 16.93 22.93 22.93 15.60 25.00- - 6.00 6.00 - - - -7.50 7.50 7.50 7.50 7.50 7.50 4.50 6.004.77 4.77 7.00 7.00 4.77 4.77 7.00 6.0010.30 10.30 10.30 10.30 10.30 10.30 17.50 17.007.00 7.00 4.77 4.77 7.00 7.00 7.00 7.00- - - - - - 1.00 2.00- - - - - - - 1.00- - - - - - 4.50 -- - - - - - 3.50 -- - - - - - 4.00 -- 2.00 - - - - - -0 0 18 18 0 0 0 029.57 31.57 29.57 29.57 29.57 29.57 37 381.373 1.373 1.373 1.373 1.373 1.373 3.889 2.8331.8212 1.796 1.7974 1.7975 1.7965 1.8972 1.873- - - - 3.634 - 3.912 3.831- - - - - - 596°C 587°C53 50 99 71 54 66 - -506 515 330 230 885 586 - -2.784 3.045 2.853 2.855 2.764 2.740 2.939 2.7422.790 3.051 2.860 2.861 2.772 2.748 2.940 2.7466.600 5.600 7.450 6.300 7.700 8.500 0.900 4.4005 2 55 3 11 60 - 2- - - - 249 - - -- - - - 1043 - - -Attorney Docket No. SP23-366PCT

[0162] As indicated by the example glass compositions in Table 1, the glass compositionsand the resultant glass articles as described herein have a refractive index (nd) greater than 1.795 as measured at 589 nm, providing more desirable optical properties for specialized applications. Furthermore, the resultant glass articles have relatively low densities, less than 3.95 g / cm3, allowing for desirable ion exchange.

[0163] Examples E1–E24, listed in Table 1, produced high quality, optically transparentglass articles free of phase separation, opalization, and devitrification as a result of the enumerated compositional requirements. The glass compositions all possessed an alumina content that was less than or equal to 4.7 mol%. The relatively low Al2O3 (e.g., less than 4.7 mol%) content and relatively low product of Al2O3 mol% x Na2O mole% (e.g., less than or equal to 19 mol%2) were necessary to create a high quality glass article free of phase separation, as high concentrations of Al2O3 and Na2O can lead to opalization and degradation of the optically transparent glass structure. Similarly, E1–E24 all (with the exception of E23) possessed a ratio of TiO2 to La2O3 that was greater than or equal to 1 and less than or equal to 3. Maintaining a ratio greater than or equal to 1 was important to achieve a suitable density for chemical strengthening, while maintaining a ratio less than or equal to 3 was also important to avoid phase separation or opalization. Furthermore, examples E1–E24 all were free of P2O5, which was necessary to maintain glass stability and to avoid devitrification of the glass articles.

[0164] Examples E1-E24 were subjected to a pure NaNO3 ion exchange bath at atemperature of 430°C for 6 hours and 45 minutes. Following ion exchange, the glass articles E1–E24 of Table 1 were characterized to determine their mass, surface compressive stress (CS), central tension (CT), and modulus of rupture (MOR).

[0165] The efficiency of chemical strengthening of the resultant glass articles was assessedby evaluating by the mass difference (Δm) of the glass article before and after being subjected to ion exchange. The chemical strengthening was considered “successful” if the mass of the chemically strengthened glass article measurably increased as a result of ion exchanged. In most of E1 to E24, the ion exchange process resulted in a significant mass increase of more than 1 mg due to the substitution of larger, more massive metal ions for smaller, less massive ions. As shown in Table 1, examples E1–E22 and E24 all had a measurable gain in mass of at least 4 mg following ion exchange due at least in part to their relatively low densities (e.g., less than 3.95 g / cm3), indicating successful chemical strengthening. E23 exhibited less ionAttorney Docket No. SP23-366PCT exchange-induced mass gain than the other samples, in part due to the TiO2 to La2O3 ratio being outside of the preferred ranges described herein.

[0166] The stress profiles, the surface compressive stress (CS), and the central tension (CT)of the glass articles were characterized with polished surfaces after ion exchange using a SCALP 5 apparatus. The glass articles were polished prior to measurement and had a thickness of 1 mm. FIG. 7 depicts the stress profile for E21 after ion exchange demonstrating the measurement of the CS and CT. Each of the examples exhibited a CS greater than or equal to 230 MPa. Each of the examples exhibited a CT greater than or equal to 40 MPa. The increased mechanical properties of the examples was a direct result of successful chemical strengthening.

[0167] FIG. 8 depicts a plot of the MOR values for E21 before and after ion exchange. Theglass articles were polished prior to measurement and had a thickness of 1 mm. FIG. 8 demonstrates that the flexural strength of the samples were approximately five times higher after chemical strengthening, with mean MOR values around 1000 MPa for the ion exchanged glass articles. MOR measurements were also performed for E6, as listed in Table 1, demonstrating a similar MOR increase with mean MOR values after chemical strengthening of around 1000 MPa.

[0168] Frangibility of the samples was also measured according to the Tip Method discussedherein. Polished glass articles with a diameter of 32 mm and a thickness of 1 mm were subjected to a controlled force via an impact probe. Frangibility was assessed based on the number of pieces or fragments the glass articles broke into after fracturing. A lower number of pieces generally corresponds to a less frangible glass article. Examples E1–E24 demonstrated a relatively low frangibility breaking into 100 pieces or less after being chemically strengthened in a pure NaNO3 ion exchange bath at a temperature of 430°C for 6 hours and 45 minutes.

[0169] Table 2 shows the Δm, CS, CT, and Tip Method frangibility results for examples E2,E4, E5, E7, E11 and E14, according to the composition described in Table 1. The samples were formed by ion exchanging glass articles having a thickness of 1 mm at temperatures of 410°C, 430°C, and 450°C for 6 hours and 45 minutes. The ion exchange solution was a 100% NaNO3 molten salt bath.Attorney Docket No. SP23-366PCT

[0170] Table 2

[0171] As indicated by Table 2, each of the samples showed an increase in ionexchangeability as a result of the increased ion exchange bath temperature, as demonstrated by the increase in mass for each sample as the ion exchange bath temperature increased. Additionally, each sample exhibited increased CS and CT values as ion exchangeability increased, as shown in Table 2. CT values may also be linked to the frangibility of the exchanged samples. Generally, lower CT values correspond with lower frangibility of a glass article.

[0172] Table 3 shows the Δm, CS, CT, and Tip Method frangibility results for example E5,according to the composition described in Table 1. The samples were formed by ion exchanging glass articles having a thickness of 1 mm at a temperatures of 430°C for 6 hours and 45 minutes. The ion exchange solutions were varied to either be a 100% NaNO3 molten salt bath or a 45% NaNO3 / 55% KNO3molten salt bath.

[0173] Table 3Weight Gain FrangibilityIOX 430°C IOX Bath Composition Δm (mg) CS (MPa) CT (MPa)(# of Pieces) E5 100% NaNO3 7.1 473 70 6545% NaNO3 | 55% KNO3 7.3 682 88 100Attorney Docket No. SP23-366PCT

[0174] As indicated in Table 3, example E5 was subjected to chemical strengthening undervaried ion exchange conditions. Glass articles of identical compositions were chemically strengthened in a 100% NaNO3 bath and a 45% NaNO3 / 55% KNO3 bath. The mass difference between the two ion exchange conditions was minimal, but the E5 sample subjected to the 45% NaNO3 / 55% KNO3ion exchange bath exhibited higher CS and CT values for a same exchange time and temperature.

[0175] Table 4 shows comparative example glass compositions (in terms of mol%) and therespective properties of the glass compositions. Glass articles were formed having the example glass compositions C1–C9.

[0176] Table 4Attorney Docket No. SP23-366PCT E1–E24. Comparative examples C1–C7 each exhibited an opalescent / opaque glass structure due to phase separation and / or devitrification, which corresponded directly to diminished optical transparency. Comparative examples C1–C4 possessed an alumina content greater than 4.7 mol% which also contributed to the observed phase separation and the diminished optical properties of the glass. Comparative examples C1, C2, C3, C5 and C7 had a product of Al2O3mol% x Na2O mol% that was greater than 19 mol%2which led to phase separation and degradation of the glass articles’ optical properties. Comparative example C6 contained P2O5which caused devitrification in the glass article, which diminished the optical transparency of the glass. Comparative examples C8 and C9 had amorphous, optically transparent glass structures, but had densities greater than 3.95 g / cm3. Accordingly, C8 and C9 exhibited a negligible mass difference after IOX, indicating a lack of ion exchangeability and thus no increase in their mechanical properties.

[0178] To further characterize the articles described herein, optical transmission and hazemeasurements were performed 1 mm thick samples with the compositions of examples 5, 6,15, 18, 21, 22, 23, and 24 described herein. Measurements were made using a Cary 5000spectrophotometer from Agilent Technology. Tristumulus Y values were measured from 380 nm to 780 nm. Haze was measured in accordance with ASTM D1003.20129. The results are shown in Table 5 below.

[0179] Table 5

[0180] As shown, the example exhibited a transmittance of greater than or equal to 80% overthe indicated spectral range and a transmission haze that is less than or equal to 0.5%. These results demonstrant the transparent nature of the glass articles described herein (when no colorant is added). It is believed that articles including a colorant will exhibit haze values consistent with the results above.Attorney Docket No. SP23-366PCT ***

[0181] Embodiments of the present disclosure may be further understood in view of thefollowing information.

[0182] It was found that it is possible to increase the La2O content and decrease the TiO2content as compared to certain ones of the preceding examples and still provide a glass article that is ion exchangeable having a high refractive index, as described herein. To demonstrate this, example glass compositions E25-E27 were formed. Table 6 shows example glass compositions (in terms of mol%) and the respective properties of the glass compositions. Glass articles were formed having the example glass compositions E25-E27

[0183] Table 6Attorney Docket No. SP23-366PCT

[0184] As shown, the example glass compositions E25-E27 were able to exhibit appreciablemass exchange after the ion exchange treatment. Examples E25-E27 were subjected to a pure NaNO3 ion exchange bath at a temperature of 430°C for 6 hours and 45 minutes. Following ion exchange, the glass articles E25–E27 of Table 1 were characterized to determine their mass, surface compressive stress (CS), and central tension (CT).

[0185] The efficiency of chemical strengthening of the resultant glass articles was assessedby evaluating by the mass difference (Δm) of the glass article before and after being subjected to ion exchange. The chemical strengthening was considered “successful” if the mass of the chemically strengthened glass article measurably increased as a result of ion exchanged. In each E25 to E27, the ion exchange process resulted in a significant mass increase of more than 3 mg due to the substitution of larger, more massive metal ions for smaller, less massive ions. As shown in Table 6, each of E25, E26, and E27 all had a measurable gain at least in part to their relatively low densities (e.g., less than 3.95 g / cm3), indicating successful chemical strengthening.

[0186] E26 and E27 were able to effectively ion exchanged, while exhibiting a refractiveindex (nd) at 589 nm is greater than or equal to 1.795, even though E26 and 27 contained greater than 9 mol La2O3. Accordingly embodiments of the glass composition and the resultant glass article include La2O3in an amount that is greater than or equal to 4 mol% and less than or equal to 11 mol%, greater than or equal to 4 mol% and less than or equal to 10.8 mol%, greater than or equal to 4 mol% and less than or equal to 10.6 mol%, greater than or equal to 7 mol% and less than or equal to 10.6 mol%, greater than or equal to 8 mol% and less than or equal to 10.6 mol%, greater than or equal to 9 mol% and less than or equal to 10.6 mol%, greater than or equal to 4 mol% or less than or equal to 9 mol%, greater than or equal to 4 mol% and less than or equal to 8 mol%, greater than or equal to 4 mol% and less than or equal to 7.5 mol%, greater than or equal to 4.5 mol% and less than or equal to 9 mol%, greater than or equal to 4.5 mol% and less than or equal to 8 mol%, greater than or equal to 4.5 mol% and less than or equal to 7.5 mol%, greater than or equal to 5 mol% and less than or equal to 9 mol%, greater than or equal to 5 mol% and less than or equal to 8 mol%, greater than or equal to 5 mol% and less than or equal to 7.5 mol%, greater than or equal to 5.5 mol% and less than or equal to 9 mol%, greater than or equal to 5.5 mol% and less than or equal to 8 mol%, greater than or equal to 5.5 mol% and less than or equal to 7.5 mol%, greater than or equal to 6 mol% and less than or equal to 9 mol%, greater than or equal to 6 mol% and less than or equal to 8 mol%, even greaterAttorney Docket No. SP23-366PCT than or equal to 6 mol% and less than or equal to 7.5 mol%, greater than or equal to 6.5 mol% and less than or equal to 9 mol%, greater than or equal to 6.5 mol% and less than or equal to 8 mol%, or even greater than or equal to 6.5 mol% and less than or equal to 7.5 mol%, or any and all sub-ranges formed from any of these endpoints.

[0187] As shown in Table 6, Examples 26 and 27 each included 0 mol% Na2O, or were freeof Na2O. Moreover, the ratio of TiO2to La2O3were greater than or equal to 0.6, consistent with the present disclosure to facilitate providing densities suitable for ion exchange. It is belived that the ratio of TiO2to La2O3may be as low as 0.55 (e.g., greater than or equal to 0.55 and less than or equal to 3.0, greater than or equal to 0.55 and less than or equal to 2, greater than or equal to 0.55 and less than or equal to 1, greater than or equal to 0.55 and less than or equal to 0.9) while still providing articles having a suitable density for ion exchange strengthening. It is also believed that the ratio of TiO2 to La2O3 may be as high as 4.0 while still providing ion exchangeable glass articles having a high refractive index. As such, in embodiments, the ratio of TiO2 to La2O3 may be greater than or equal to 0.55 and less than or equal to 4.0 in various embodiments.

[0188] Example 27 further included TiO2 in an amount that is less than or equal to 7 mol%while still exhibiting the requisite density for ion exchangability and high refractive index. Accordingly, the glass compositions and resultant articles of the present disclosure may include TiO2in an amount that is greater than or equal to 6.4 mol% and less than or equal to 25 mol%, greater than or equal to 6.4 mol% and less than or equal to 22 mol%, greater than or equal to 6.4 mol% and less than or equal to 18 mol%, greater than or equal to 6.4 mol% and less than or equal to 25 mol%,%, greater than or equal to 6.4 mol% and less than or equal to 7 mol%, greater than or equal to 8 mol% and less than or equal to 21 mol%, greater than or equal to 8 mol% and less than or equal to 25 mol%, greater than or equal to 8 mol% and less than or equal to 17.5 mol%, greater than or equal to 9 mol% and less than or equal to 25 mol%, greater than or equal to 9 mol% and less than or equal to 22 mol%, greater than or equal to 9 mol% and less than or equal to 18 mol%, greater than or equal to 10 mol% and less than or equal to 25 mol%, greater than or equal to 10 mol% and less than or equal to 22 mol%, greater than or equal to 10 mol% and less than or equal to 18 mol%, greater than or equal to 11 mol% and less than or equal to 25 mol%, greater than or equal to 11 mol% and less than or equal to 22 mol%, greater than or equal to 11 mol% and less than or equal to 18 mol%, greater than or equal to 12 mol% and less than or equal to 25 mol%, greater than or equal to 12 mol% and less than or equal toAttorney Docket No. SP23-366PCT 22 mol%, or even greater than or equal to 12 mol% and less than or equal to 18 mol%, or any and all sub-ranges formed from any of these endpoints. E25, 26, 27 had amounts of B2O3, Al2O3, Li2O, Nb2O5, and Na2O that were consistent with those of other Examples described herein.

[0189] E25, E26, and E27 demonstrate that substituting limited amounts of certain ones ofthe high refractive index oxides can yield glass compositions having suitable density for ion exchange while still providing a high refractive index. For example, as compared to E25, Example E26 added La2O3 and Nb2O5while removed TiO2and ZrO2, but the glass article was still ion exchangeable. As compared to E26, E27 further substituted more La2O3 for TiO2 (lowered the amount to TiO2 and increased the amount of La2O3), and still yielded an ion exchangeable article with a suitably high refractive index. The amounts of SiO2, B2O3, Al2O3, Li2O, and Na2O in Examples E26 and E27 were the same. E27 demonstrates that compositions where La2O3 is high refractive index oxide with the greatest amount (La2O3 is present in an amount that is 2.6 mol% greater than the nearest one of TiO2, ZrO2, and Y2O3 in E27) can yield articles having the high refractive index, despite having a lower overall amount of high refractive index oxides (compare E25 to E27).

[0190] It will be apparent to those skilled in the art that various modifications and variationsmay be made to the embodiments described herein without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the specification cover the modifications and variations of the various embodiments described herein provided such modification and variations come within the scope of the appended claims and their equivalents.

Claims

Attorney Docket No. SP23-366PCT CLAIMS1. A glass composition comprising:greater than or equal to 30 mol% and less than or equal to 50 mol% SiO2; greater than or equal to 0.5 mol% and less than or equal to 4.7 mol% Al2O3; greater than or equal to 14 mol% and less than or equal to 27 mol% Li2O; greater than or equal to 4 mol% and less than or equal to 9 mol% La2O3; greater than or equal to 4 mol% and less than or equal to 10 mol% Nb2O5; greater than or equal to 7 mol% and less than or equal to 25 mol% TiO2; and greater than or equal to 0 mol% and less than or equal to 7 mol% Na2O, wherein a product of Al2O3 × Na2O is less than or equal to 19 mol%2.

2. The glass composition of claim 1, wherein the product of Al2O3 × Na2O is less than orequal to 18 mol%2.

3. The glass composition of claim 1 or 2, wherein the glass composition comprises: greaterthan or equal to 1 mol% and less than or equal to 4.5 mol% Al2O3.

4. The glass composition of any one of claims 1 to 3, wherein the glass compositioncomprises greater than or equal to 1 mol% and less than or equal to 6 mol% Na2O.

5. The glass composition of any one of claims 1 to 4, wherein a ratio of TiO2 to La2O3 is greater than or equal to 1 and less than or equal to 3.

6. The glass composition of claim 5, wherein the ratio of TiO2to La2O3is greater than or equal to 1 and less than or equal to 2.

7. The glass composition of any one of claims 1 to 6, wherein a sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5is greater than or equal to 27 mol%.

8. The glass composition of any one of claims claim 1 to 7, wherein the glass compositionis free or substantially free of P2O5.Attorney Docket No. SP23-366PCT9. The glass composition of any one of claims 1 to 8, wherein the glass compositioncomprises greater than 0 mol% and less than or equal to 3 mol% Y2O3.

10. The glass composition of any one of claims 1 to 9, wherein the glass composition comprises greater than 0 mol% and less than or equal to 4.5 mol% Ta2O5.

11. The glass composition of any one of claims 1 to 10, wherein the glass composition comprises greater than 0 mol% and less than or equal to 12 mol% B2O3.

12. The glass composition of any one of claims 1 to 11, wherein the glass composition comprises greater than 0 mol% and less than or equal to 5 mol% K2O.

13. The glass composition of any one of claims 1 to 12, wherein the glass composition comprises: greater than or equal to 0 mol% and less than or equal to 5 mol% BaO; greater than or equal to 0 mol% and less than or equal to 5 mol% SrO; greater than or equal to 0 mol% and less than or equal to 5 mol% ZnO; and greater than or equal to 0 mol% and less than or equal to 5 mol% CaO.

14. The glass composition of any one of claims 1 to 13, wherein the glass composition comprises greater than or equal to 5 mol% and less than or equal to 9 mol% Nb2O5.

15. The glass composition of any one of claims 1 to 14, wherein the glass composition comprises greater than or equal to 5 mol% and less than or equal to 8 mol% La2O3.

16. The glass composition of any one of claims 1 to 15, wherein the glass composition comprises greater than 0 mol% and less than or equal to 9 mol% ZrO2.

17. The glass composition of any one of claims 1 to 16, wherein the glass composition comprises greater than or equal to 8 mol% and less than or equal to 21 mol% TiO2.

18. The glass composition of any one of claims 1 to 17, wherein the glass composition comprises greater than or equal to 14.5 mol% and less than or equal to 25 mol% Li2O.Attorney Docket No. SP23-366PCT 19. The glass composition of any one of claims 1 to 18, wherein the glass composition comprises greater than or equal to 33 mol% and less than or equal to 47 mol% SiO2.

20. A glass article comprising: greater than or equal to 30 mol% and less than or equal to 50 mol% SiO2; greater than or equal to 0.5 mol% and less than or equal to 4.7 mol% Al2O3; greater than or equal to 14 mol% and less than or equal to 27 mol% Li2O; greater than or equal to 0 mol% and less than or equal to 7 mol% Na2O, wherein a product of Al2O3 mol % × Na2O mol % is less than or equal to 19 mol%2; and a sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5 that is greater than or equal to 27 mol%, wherein the glass article is a chemically strengthened glass article and comprises: a refractive index (nd) at 589 nm greater than or equal to 1.795, and a surface compressive stress, after the chemical strengthening, greater than or equal to 230 MPa.

21. The glass article of claim 20, wherein the product of Al2O3× Na2O is less than or equal to 18 mol%2.

22. The glass article of claims 20 or 21, wherein the glass article comprises greater than or equal to 1 mol% and less than or equal to 4.5 mol% Al2O3.

23. The glass article of any one of claims 20 to 22, wherein the glass article comprises greater than or equal to 1 mol% and less than or equal to 6 mol% Na2O.

24. The glass article of any one of claims 20 to 23, wherein a ratio of TiO2 to La2O3 is greater than or equal to 0.6 and less than or equal to 3.

25. The glass article of claim 24, wherein the ratio of TiO2 to La2O3 is greater than or equal to 1 and less than or equal to 2.Attorney Docket No. SP23-366PCT 26. The glass article of any one of claims 20 to 25, wherein the sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5 is greater than or equal to 29 mol%.

27. The glass article of any one of claims claim 20 to 26, wherein the glass article is free or substantially free of P2O5.

28. The glass article of any one of claims 20 to 27, wherein the glass article comprises greater than 0 mol% and less than or equal to 3 mol% Y2O3.

29. The glass article of any one of claims 20 to 28, wherein the glass article comprises greater than 0 mol% and less than or equal to 4.5 mol% Ta2O5.

30. The glass article of any one of claims 20 to 29, wherein the glass article comprises greater than 0 mol% and less than or equal to 12 mol% B2O3.

31. The glass article of any one of claims 20 to 30, wherein the glass article comprises greater than 0 mol% and less than or equal to 5 mol% K2O.

32. The glass article of any one of claims 20 to 31, wherein the glass article comprises: greater than or equal to 0 mol% and less than or equal to 5 mol% BaO; greater than or equal to 0 mol% and less than or equal to 5 mol% SrO; greater than or equal to 0 mol% and less than or equal to 5 mol% ZnO; and greater than or equal to 0 mol% and less than or equal to 5 mol% CaO.

33. The glass article of any one of claims 20 to 32, wherein the glass article comprises greater than or equal to 5 mol% and less than or equal to 9 mol% Nb2O5.

34. The glass article of any one of claims 20 to 33, wherein the glass article comprises greater than or equal to 5 mol% and less than or equal to 8 mol% La2O3.

35. The glass article of any one of claims 20 to 34, wherein the glass article comprises greater than 0 mol% and less than or equal to 9 mol% ZrO2.Attorney Docket No. SP23-366PCT 36. The glass article of any one of claims 20 to 35, wherein the glass article comprises greater than or equal to 8 mol% and less than or equal to 21 mol% TiO2.

37. The glass article of any one of claims 20 to 36, wherein the glass article comprises greater than or equal to 14.5 mol% and less than or equal to 25 mol% Li2O.

38. The glass article of any one of claims 20 to 37, wherein the glass article comprises greater than or equal to 33 mol% and less than or equal to 47 mol% SiO2.

39. The glass article of any one of claims 20 to 38, wherein the refractive index (nd) at 589 nm of the glass article is greater than or equal to 1.

82.

40. The glass article of any one of claims 20 to 39, wherein the glass article comprises a density less than 3.95 g / cm3.

41. The glass article of any one of claims 20 to 40, wherein the chemical strengthening comprises subjecting the glass article to an ion exchange bath comprising one or more molten salts, wherein the glass article is subjected to the ion exchange bath at a temperature greater than or equal to 380 °C.

42. The glass article of claim 41, wherein the ion exchange bath comprises NaNO3.

43. The glass article of claim 41, wherein the ion exchange bath comprises bath comprises NaNO3, KNO3, or combinations thereof.

44. The glass article of any one of claims 41 to 43, wherein the glass article comprises a glass transition temperature (Tg) greater than the temperature of the ion exchange bath.

45. The glass article of any one of claims 41 to 44, wherein the glass article is subjected to the ion exchange bath comprising NaNO3 at a temperature of 430°C for 6 hours and 45 minutes, and wherein the glass article breaks into less than 100 pieces, as measured at an article thickness of 1 mm by a tip method.Attorney Docket No. SP23-366PCT 46. The glass article of any one of claims 20 to 45, wherein the glass article comprises a modulus of rupture (MOR) greater than 600 MPa when the glass article has a thickness of at least 1 mm.

47. The glass article of any one of claims 20 to 46, wherein the glass article comprises a peak surface compressive stress greater than or equal to 300 MPa.

48. The glass article of any one of claims 20 to 47, wherein the glass article comprises a maximum central tension greater than or equal to 40 MPa when the glass article has a thickness of at least 1 mm.

49. A glass composition comprising: greater than or equal to 33 mol% and less than or equal to 47 mol% SiO2; greater than or equal to 1 mol% and less than or equal to 4.5 mol% Al2O3; greater than or equal to 15 mol% and less than or equal to 25 mol% Li2O; greater than or equal to 4 mol% and less than or equal to 8 mol% La2O3; greater than or equal to 4 mol% and less than or equal to 8 mol% Nb2O5; greater than or equal to 8 mol% and less than or equal to 21 mol% TiO2; greater than or equal to 3 mol% and less than or equal to 8 mol% ZrO2; greater than or equal to 3 mol% and less than or equal to 6 mol% Na2O; wherein a product of Al2O3mol% × Na2O mol% is less than or equal to 19 mol%2; and the glass composition is free or substantially free of P2O5.

50. The glass composition of claim 49, wherein the product of Al2O3 × Na2O is less than or equal to 18 mol%2.

51. The glass composition of claim 49 or 50, wherein a ratio of TiO2 mol % to La2O3 mol% is greater than or equal to 0.6 and less than or equal to 3.

52. The glass composition of claim 51, wherein the ratio of TiO2mol % to La2O3mol% is greater than or equal to 1 and less than or equal to 2.Attorney Docket No. SP23-366PCT 53. The glass composition of any one of claims 49 to 52, wherein a sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5 is greater than or equal to 27 mol%.

54. The glass composition of any one of claims 49 to 53, wherein the glass composition comprises greater than 0 mol% and less than or equal to 3 mol% Y2O3.

55. The glass composition of any one of claims 49 to 54, wherein the glass composition comprises greater than 0 mol% and less than or equal to 4.5 mol% Ta2O5.

56. The glass composition of any one of claims 49 to 55, wherein the glass composition comprises greater than 0 mol% and less than or equal to 12 mol% B2O3.

57. The glass composition of any one of claims 49 to 56, wherein the glass composition comprises greater than 0 mol% and less than or equal to 5 mol% K2O.

58. The glass composition of any one of claims 49 to 57, wherein the glass composition comprises: greater than or equal to 0 mol% and less than or equal to 5 mol% BaO; greater than or equal to 0 mol% and less than or equal to 5 mol% SrO; greater than or equal to 0 mol% and less than or equal to 5 mol% ZnO; and greater than or equal to 0 mol% and less than or equal to 5 mol% CaO.

59. A glass composition comprising: greater than or equal to 30 mol% and less than or equal to 50 mol% SiO2; greater than or equal to 0.5 mol% and less than or equal to 4.7 mol% Al2O3; greater than or equal to 14 mol% and less than or equal to 27 mol% Li2O; greater than or equal to 4 mol% and less than or equal to 11 mol% La2O3; greater than or equal to 4 mol% and less than or equal to 10 mol% Nb2O5; greater than or equal to 6.4 mol% and less than or equal to 25 mol% TiO2; and greater than or equal to 0 mol% and less than or equal to 7 mol% Na2O, wherein a product of Al2O3 × Na2O is less than or equal to 19 mol%2.Attorney Docket No. SP23-366PCT 60. The glass composition of claim 59, wherein a ratio of TiO2 to La2O3 is greater than or equal to 0.55 and less than or equal to 4.

61. The glass composition of claim 60, wherein the ratio of TiO2 to La2O3 is greater than or equal to 0.6 and less than or equal to 2.

62. The glass composition of any one of claims 59 to 61, wherein a sum of La2O3, Nb2O5, TiO2, ZrO2, Y2O3, and Ta2O5is greater than or equal to 29 mol%.

63. The glass composition of any one of claims claim 59 to 62, wherein the glass composition is free or substantially free of P2O5.

64. The glass composition of any one of claims 59 to 63, wherein the glass composition comprises greater than or equal to 5 mol% and less than or equal to 9 mol% Nb2O5.

65. The glass composition of any one of claims 59 to 64, wherein the glass composition comprises greater than or equal to 8 mol% and less than or equal to 21 mol% TiO2.

66. The glass composition of any one of claims 59 to 65, wherein the glass composition comprises greater than or equal to 14.5 mol% and less than or equal to 25 mol% Li2O.

67. The glass composition of any one of claims 59 to 66, wherein the glass composition comprises greater than or equal to 33 mol% and less than or equal to 47 mol% SiO2.

68. A glass article formed from a glass composition according to any one of claims 59-67, wherein the glass article is a chemically strengthened glass article and comprises: a refractive index (nd) at 589 nm greater than or equal to 1.795, and a surface compressive stress, after the chemical strengthening, greater than or equal to 230 MPa.

69. The glass article according to claim 68, wherein the refractive index (nd) at 589 nm of the glass article is greater than or equal to 1.82.Attorney Docket No. SP23-366PCT 70. The glass article of any one of claims 68 to 69, wherein the glass article comprises a density less than 3.95 g / cm3.

71. The glass article of any one of claims 68 to 70, wherein, when the glass article is subjected to an ion exchange bath comprising NaNO3at a temperature of 430°C for 6 hours and 45 minutes, and the glass article breaks into less than 100 pieces, as measured at an article thickness of 1 mm by a tip method.

72. The glass article of claim 71, wherein the glass article comprises a peak surface compressive stress greater than or equal to 270 MPa after being subjected to the ion exchange bath.

73. The glass article of any one of claims 68 to 72, wherein the glass article comprises a maximum central tension greater than or equal to 28 MPa when the glass article has a thickness of at least 1 mm.

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