Dimensionally stable fast etching glasses

Abstract

To provide substantially alkali-free glasses with can be used to produce substrates for flat panel display devices, e.g., active-matrix liquid crystal displays (AMLCDs).SOLUTION: A glass comprises, in mole percent on an oxide basis, SiO2 of 68.5-72.0, Al2O3 of greater than or equal to 13.0, B2O3 of less than or equal to 2.5, MgO of 1.0-6.0, CaO of 4.0-8.0, SrO of less than or equal to 4.5, and BaO of less than or equal to 4.5, wherein the Na2O content is 1 ppm by weight to 259 ppm by weight, the ratio (MgO+CaO+SrO+BaO) / Al2O3 is less than or equal to 1.6, the Young's modulus is >82 GPa, T(ann) is >800°C, and the etch index is greater than or equal to 23.SELECTED DRAWING: Figure 4A

Description

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 62 / 617,386, filed January 15, 2015, the contents of which are relied upon and incorporated by reference in their entirety into this application. [Technical Field]

[0002] FIELD OF THE DISCLOSURE Embodiments of the present disclosure relate to display glass, and more particularly, to display glass for active matrix liquid crystal displays. [Background technology]

[0003] The manufacture of liquid crystal displays, such as active matrix liquid crystal display (AMLCD) devices, is complex, and the properties of the substrate glass are important. First and foremost, the physical dimensions of the glass substrates used in the manufacture of AMLCD devices must be tightly controlled. Downdraw sheet drawing processes, and in particular the fusion process described in U.S. Patent Nos. 5,629,997 and 5,729,997 to Dockerty, can produce glass sheets that can be used as substrates without the need for costly post-formation finishing operations such as lapping and polishing. Unfortunately, the fusion process imposes relatively severe constraints on the properties of the glass, which in turn necessitate a relatively high liquidus viscosity.

[0004] In the field of liquid crystal displays, polycrystalline silicon-based thin film transistors (TFTs) are preferred due to their ability to transport electrons relatively efficiently. Polycrystalline-based silicon transistors (p-Si) are characterized by higher mobility than amorphous silicon-based transistors (a-Si). This allows for the fabrication of smaller and faster transistors, which ultimately leads to brighter and faster displays.

[0005] One problem with p-Si-based transistors is that their fabrication requires higher process temperatures than those employed in the fabrication of a-Si transistors. These temperatures range from 450°C to 600°C, compared to the peak temperature of 350°C employed in the fabrication of a-Si transistors. At these temperatures, most AMLCD glass substrates undergo a process known as compaction. Compaction, also known as thermal stabilization or dimensional change, is the irreversible dimensional change (shrinkage) of a glass substrate due to a change in the glass's fictive temperature. "Fictive temperature" is a concept used to describe the structural state of glass. Glass that is rapidly cooled from a high temperature is said to have a higher fictive temperature because its high-temperature structure is "frozen in." Glass that is cooled more slowly, i.e., glass that is annealed by holding it near the annealing point for a certain period of time, is said to have a lower fictive temperature.

[0006] There are two approaches to minimizing glass compaction. The first approach is to thermally pre-treat the glass to create a fictive temperature similar to that the glass will experience during p-Si TFT fabrication. This approach has several drawbacks. First, the multiple heating steps employed during p-Si TFT fabrication create multiple slightly different fictive temperatures in the glass that cannot be fully compensated for by this pre-treatment. Second, the thermal stability of the glass is closely linked to the details of p-Si TFT fabrication, which may mean that different pre-treatments are required for different end users. Finally, pre-treatments increase processing costs and complexity.

[0007] Another approach is to slow the strain rate at the process temperature by increasing the viscosity of the glass. This can be achieved by increasing the viscosity of the glass. The annealing point represents the temperature corresponding to a fixed viscosity for a glass, so increasing the annealing point is equivalent to increasing the viscosity at a fixed temperature. However, a challenge with this approach is the cost-effective production of high-annealing-point glasses. The major factors affecting cost are defects and equipment life. In modern melters coupled to fusion draw machines, four types of defects generally appear: (1) gas inclusions (bubbles or bubbles); (2) solid inclusions from the refractories or due to failure to properly melt the batch; (3) metal-based defects, mostly composed of platinum; and (4) devitrification products, caused by low liquidus viscosity or excessive devitrification at both ends of the isopipe. Glass composition has an inordinate effect on the melting rate and therefore on the tendency of the glass to form gas or solid state defects, and the oxidation state of the glass affects the tendency to incorporate platinum-based defects. Devitrification of the glass on the forming mandrel, or isopipe, is best addressed by selecting a composition with a high liquidus viscosity.

[0008] Equipment life is primarily determined by the rate of wear or deformation of the various refractory and precious metal components of the melting and forming system. Recent advances in refractory materials, platinum-based designs, and isopipe refractories offer the potential for significantly extending the useful operating life of melters coupled to fusion draw machines. As a result, the life-limiting components of modern fusion draw melting and forming platforms are the electrodes used to heat the glass. Tin oxide electrodes corrode slowly over time, and the corrosion rate is a strong function of both temperature and glass composition. To maximize equipment life, it is desirable to identify compositions that reduce the electrode corrosion rate while maintaining the defect-limiting attributes discussed above.

[0009] As long as the compaction of the glass is below a threshold level, a key attribute determining the suitability of a glass as a substrate is the total pitch variability, or lack thereof, of the substrate during TFT fabrication, which can cause misalignment of TFT components and result in defective pixels in the final display. This variability is most significantly due to variations in glass compaction, variations in the elastic strain of the glass under stresses applied by films deposited during TFT fabrication, and variations in the relaxation of these stresses during TFT fabrication. Glasses with high dimensional stability have low compaction variability and low stress relaxation, and glass with a high Young's modulus helps reduce distortion due to film stress. Thus, glasses with both a high Young's modulus and high dimensional stability minimize total pitch variability during the TFT process, making them advantageous substrates for these applications.

[0010] While total pitch variability is an important attribute for the suitability of a glass composition for use as a TFT backplane, other attributes are also of considerable importance. After TFT fabrication is complete, panel manufacturers thin the display by acid etching to reduce the thickness and weight of the final display. Thus, glasses that etch quickly in commercially available acid compositions allow for more economical thinning of the glass. Similarly, low-density glasses also contribute to the desired reduction in the weight of the final display. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] U.S. Patent No. 3,338,696 [Patent Document 2] U.S. Patent No. 3,682,609 Summary of the Invention [Problem to be solved by the invention]

[0012] The amount of compaction depends on both the process by which the glass is made and the viscoelastic properties of the glass. In the float process for producing sheet products from glass, the glass sheet cools relatively slowly from the melt, thus "freezing in" relatively low-temperature structures within the glass. In contrast, the fusion process results in extremely rapid quenching of the glass sheet from the melt, freezing in relatively high-temperature structures within the glass. As a result, glass produced by the float process may experience less compaction than glass produced by the fusion process, because the force responsible for compaction is the difference between the fictive temperature and the process temperature experienced by the glass during compaction. Therefore, it is desirable to minimize the level of compaction in glass substrates produced by the downdraw process.

[0013] Additionally, there is a need in the art for glass compositions that have a high Young's modulus and high dimensional stability while allowing for reliable reduction in thickness and other advantageous properties and characteristics. [Means for solving the problem]

[0014] Various embodiments include 1 ppm to about 259 ppm by weight, about 1 ppm to about 255 ppm by weight, about 1 ppm to about 250 ppm by weight, about 1 ppm to about 245 ppm by weight, about 1 ppm to about 240 ppm by weight, about 1 ppm to about 235 ppm by weight, about 1 ppm to about 230 ppm by weight, about 1 ppm to about 225 ppm by weight, about 1 ppm to about 220 ppm by weight, about 1 ppm to about 215 ppm by weight, about 1 ppm to about 2 10 ppm by weight, approx. 1 ppm to approx. 205 ppm by weight, approx. 1 ppm to approx. 200 ppm by weight, approx. 1 ppm to approx. 195 ppm by weight, approx. 1 ppm to approx. 190 ppm by weight, approx. 1 ppm by weight to approx. 180 ppm by weight, approx. 1 ppm to approx. 175 ppm by weight, approx. 1 ppm to approx. 170 ppm by weight, approx. 1 ppm to approx. 165 ppm by weight, approx. 1 ppm to approx. 160 ppm by weight, approx. 1 ppm to approx. 15 5 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm to about 145 ppm by weight, about 1 ppm to about 140 ppm by weight, about 1 ppm to about 135 ppm by weight, about 1 ppm to about 130 ppm by weight, about 1 Weight ppm to approx. 125 weight ppm, approx. 1 weight ppm to approx. 120 weight ppm, approx. 1 weight ppm to approx. 115 weight ppm, approx. 1 weight ppm to approx. 110 weight ppm, approx. 1 weight ppm to approx. 105 weight ppm, approx. 1 weight ppm to approx. 100 The present disclosure is directed to glasses having a NaO content of about 1 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight. In one or more embodiments, glass sheets comprising such glasses, and consumer electronic products comprising such glass sheets, are described herein. Such glasses may be according to the embodiments described below.

[0015] One or more embodiments of the present disclosure are directed to a glass comprising, in mole percent on an oxide basis, 68.5-72.0 SiO, about 13.0 or more AlO, about 2.5 or less BO, 1.0-6.0 MgO, 4.0-8.0 CaO, about 4.5 or less SrO, and about 4.5 or less BaO, such that (MgO+CaO+SrO+BaO) / AlO is about 1.6 or less, the glass having an etch index of about 23 or greater, an annealing point of about 800°C or greater, and a Young's modulus greater than 82 GPa.

[0016] One or more embodiments provide a glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-3.0 B2O3, 0.9-9.0 MgO, 5.25-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, wherein the glass is substantially alkali-free and has a glass content of >21 μm / mm 3 In some embodiments, the glass comprises, in mole percent on an oxide basis, 68.0-71.0 SiO2, >0-2.0 BO, 3.5-5.0 MgO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0017] One or more embodiments provide a glass comprising, in mole percent on an oxide basis, 68.0-70.5 SiO2, 13.0-14.0 Al2O3, >0-3.0 B2O3, 0.9-9.0 MgO, 5.25-11 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, wherein the glass is substantially alkali-free and has a glass content of >21 μm / mm 3 In some embodiments, the glass comprises, in mole percent on an oxide basis, >0-2.0 B2O3, 3.5-5.0 MgO, 5.25-10.0 CaO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0018] One or more embodiments provide a glass comprising, in mole percent on an oxide basis, 63.0-75.0 SiO2, 13.0-14.0 Al2O3, >0-2.8 B2O3, 0.9-9.0 MgO, 5.25-11 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, wherein the glass is substantially alkali-free and has a glass content of >21 μm / mm 3 In some embodiments, the glass comprises, in mole percent on an oxide basis, 68.0-72.0 SiO2, >0-2.0 BO3, 3.5-5.0 MgO, 5.25-10.0 CaO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0019] One or more embodiments of the present disclosure provide a glass comprising, in mole percent on an oxide basis, 63.0-75.0 SiO2, 13.0-14.0 Al2O3, >0-3.0 B2O3, 0.9-9.0 MgO, 5.25-11 CaO, >0-6.0 SrO, and 3.0-5.4 BaO, wherein the glass is substantially alkali-free and has a glass surface roughness of >21 μm / mm 3 In some embodiments, the glass comprises, in mole percent on an oxide basis, 68.0-72.0 SiO2, >0-2.0 BO3, 3.5-5.0 MgO, 5.25-10.0 CaO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0020] One or more embodiments of the present disclosure provide a glass comprising, in mole percent on an oxide basis, 63.0-75.0 SiO2, 13.0-14.5 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.0-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, wherein the glass is substantially alkali-free, has a (MgO+CaO+SrO+BaO) / Al2O3 of 1.1-1.6, and a SiO2 content of >21 μm / mm 3In some embodiments, the glass comprises, in mole percent on an oxide basis, 68.0-72.0 SiO2, 3.5-5.0 MgO, 5.25-6.5 CaO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0021] One or more embodiments provide a glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.25-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, wherein the glass is substantially alkali-free and has a glass content of >21 μm / mm 3 In some embodiments, the glass comprises, in mole percent on an oxide basis, 68.0-71.0 SiO2, 3.5-5.0 MgO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0022] One or more embodiments provide a glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.0-6.5 CaO, >0-6.0 SrO, and 3.5-4.0 BaO, wherein the glass is substantially alkali-free and has a glass content of >21 μm / mm 3 In some embodiments, the glass comprises, in mole percent on an oxide basis, 68.0-71.0 SiO2, 3.5-5.0 MgO, and >0-2.0 SrO.

[0023] One or more embodiments provide a glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.0-6.5 CaO, >0-6.0 SrO, 1.0-9.0 BaO, with the sum of CaO and BaO >8.6, wherein the glass is substantially alkali-free and has a glass thickness of >21 μm / mm 3In some embodiments, the glass comprises, in mole percent on an oxide basis, 68.0-71.0 SiO2, 3.5-5.0 MgO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0024] Further embodiments of the present disclosure include: an annealing temperature of about 785°C or greater; a density of about 2.65 g / cc or less; a T of about 1750°C or less. 200P ; T below approximately 1340°C 35kP a Young's modulus of about 82 GPa or greater; and a thickness of about 21 μm / mm, defined by the formula: -54.6147 + (2.50004) * (Al2O3) + (1.3134) * (B2O3) + (1.84106) * (MgO) + (3.01223) * (CaO) + (3.7248) * (SrO) + (4.13149) * (BaO) 3 In some embodiments, the glass has an annealing temperature of about 800° C. or greater; a density of about 2.61 g / cc or less; a T of about 1700° C. or less; and is substantially alkali-free. 200P ; T below approximately 1310°C 35kP and / or about 21 μm / mm 3In various embodiments, the glass comprises one or more of: SiO2 between 68.1 and 72.3 mole percent on an oxide basis; Al2O3 between 11.0 and 14.0 mole percent on an oxide basis; B2O3 >0-3.0 mole percent on an oxide basis; MgO between 1.0 and 7.2 mole percent on an oxide basis; MgO between 3.1 and 5.8 mole percent on an oxide basis; CaO between 4.1 and 10.0 mole percent on an oxide basis; CaO between 4.5 and 7.4 mole percent on an oxide basis; SrO >0-4.2 mole percent on an oxide basis; SrO >0-2.0 mole percent on an oxide basis; BaO between 1.2 and 4.4 mole percent on an oxide basis; and / or BaO between 2.6 and 4.4 mole percent on an oxide basis. In some embodiments, the glass comprises, in mole percent on an oxide basis, 68.0-72.0 SiO2, 0.1-3.0 B2O3, and 5.0-6.5 CaO. In one or more embodiments, the glass comprises, in mole percent on an oxide basis, 13.0-14.0 Al2O3, 0.1-3.0 B2O3, and 5.25-6.0 CaO.

[0025] Some embodiments of the present disclosure are directed to a substantially alkali-free glass comprising, in mole percent on an oxide basis, 69.76-71.62 SiO, 11.03-13.57 AlO, 0-2.99 BO, 3.15-5.84 MgO, 4.55-7.35 CaO, 0.2-1.99 SrO, 2.61-4.41 BaO, and 0-1.0 ZnO, wherein the ratio (MgO+CaO+SrO+BaO) / AlO is about 1.0-1.6 and the ratio MgO / (MgO+CaO+SrO+BaO) is about 0.22-0.37.

[0026] One or more embodiments of the present disclosure are directed to a substantially alkali-free glass comprising, in mole percent on an oxide basis, 68.14-72.29 SiO, 11.03-14.18 AlO, 0-2.99 BO, 1.09-7.2 MgO, 4.12-9.97 CaO, 0.2-4.15 SrO, 1.26-4.41 BaO, and 0-1.0 ZnO, wherein the ratio (MgO+CaO+SrO+BaO) / AlO is about 1.0-1.6 and the ratio MgO / (MgO+CaO+SrO+BaO) is about 0.22-0.37.

[0027] Some embodiments of the present disclosure are directed to a substantially alkali-free glass, the glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 between about 1.0 and 1.6, a ratio MgO / (MgO+CaO+SrO+BaO) between about 0.22 and 0.37, a T(ann) of >785°C, a density of <2.65 g / cc, a T(200P) of <1750°C, a T(35 kP) of <1340°C, a Young's modulus of >82 GPa, and a Young's modulus of >21 μm / mm 3 It has an etching index of

[0028] A further embodiment of the present disclosure is a substantially alkali-free glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0-1.6, a ratio MgO / (MgO+CaO+SrO+BaO) of about 0.22-0.37, and an Etch Index >21 μm / mm 3 This applies to glass.

[0029] In one or more embodiments, the substantially alkali-free glass has a ratio (MgO+CaO+SrO+BaO) / Al2O3 between about 1.0 and 1.6, a ratio MgO / (MgO+CaO+SrO+BaO) between about 0.22 and 0.37, and a liquidus viscosity >150 kP (15 kP·a).

[0030] Some embodiments of the present disclosure provide a substantially alkali-free glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to about 1.6 and an etching index of 21 μm / mm3 The glass is of the type above, with T(ann) >800°C and Young's modulus >82 GPa.

[0031] A further embodiment of the present disclosure is directed to a substantially alkali-free aluminosilicate glass article having: an annealing temperature of about 795°C or greater; a density of about 2.63 g / cc or less; a T of about 1730°C or less; 200P ; T below approximately 1320°C 35kP ; Young's modulus of about 81.5 GPa or more; and about 23 μm / mm 3 It has an etching index of at least 1000 ppm.

[0032] A further embodiment of the present disclosure is directed to a substantially alkali-free aluminosilicate glass article having: an annealing temperature of about 800°C or greater; a density of about 2.61 g / cc or less; a T of about 1710°C or less; 200P ; T below approximately 1310°C 35kP ; Young's modulus of about 81.2 GPa or more; and about 23 μm / mm 3 It has an etching index of at least 1000 ppm.

[0033] Further embodiments of the present disclosure are directed to objects comprising glass produced by a downdraw sheet fabrication process. Further embodiments are directed to glass produced by a fusion process or variations thereof.

[0034] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate several embodiments described below. [Brief explanation of the drawings]

[0035] [Figure 1] Schematic of a forming mandrel used to create precision sheet in the fusion draw process [Figure 2] 6 is a cross-sectional view of the forming mandrel of FIG. 1 taken along location 6. [Figure 3]Spectra for 1200°C and 1140°C blackbody and transmission spectrum of 0.7mm thick EagleXG® amorphous thin film transistor substrate [Figure 4A] FIG. 1 is a plan view of an exemplary electronic device incorporating a coated glass-based article as disclosed herein. [Figure 4B] FIG. 4B is a perspective view of the exemplary electronic device of FIG. [Figure 5] 1 is a graph showing normalized stress relaxation ratios at 30 minutes at 450° C., 550° C., and 650° C., with a baseline NaO concentration of 260 ppm. [Figure 6] Graph showing normalized stress relaxation ratio relative to 260 ppm Na2O as a function of time at 550°C. [Figure 7] Graph showing compaction at 500°C versus Na2O content for a 30 minute cycle DETAILED DESCRIPTION OF THE INVENTION

[0036] Described herein are alkali-free glasses and methods for making the same, which have a high annealing point and a high Young's modulus, enabling excellent dimensional stability (i.e., low compaction) during TFT fabrication and reduced variability during the TFT process. Glasses with high annealing points can help prevent panel distortion due to compaction / shrinkage during thermal processes subsequent to glass fabrication. Additionally, some embodiments of the present disclosure have high etch rates that enable economical backside thinning and extremely high liquidus viscosities that reduce or eliminate the possibility of devitrification on relatively low-temperature forming mandrels. Due to specific details of their composition, exemplary glasses are of high quality when melted, have extremely low levels of gas inclusions, and exhibit minimal attack on precious metals, refractories, and tin oxide electrode materials.

[0037] In one embodiment, the substantially alkali-free glass can have a high annealing point. In some embodiments, the annealing point is greater than or equal to about 785° C., 790° C., 795° C., or 800° C. Without being bound to any particular theory of operation, it is believed that such a high annealing point results in a low relaxation rate and therefore relatively little compaction relative to exemplary glasses used as backside substrates in low temperature polysilicon processes.

[0038] Heretofore, it was thought that there was no benefit in reducing the NaO content in alkali-free glasses to contain less than 260 ppm (0.026 wt%) by weight. In accordance with one or more embodiments, it has been determined that reducing the NaO content in alkali-free glasses to less than 260 ppm has a surprising and beneficial impact on compaction, particularly on low temperature cycling.

[0039] In specific embodiments, the glass contains from about 1 ppm to about 259 ppm by weight, from about 1 ppm to about 255 ppm by weight, from about 1 ppm to about 250 ppm by weight, from about 1 ppm to about 245 ppm by weight, from about 1 ppm to about 240 ppm by weight, from about 1 ppm to about 235 ppm by weight, from about 1 ppm to about 230 ppm by weight, from about 1 ppm to about 225 ppm by weight, from about 1 ppm to about 220 ppm by weight, from about 1 ppm to about 215 ... Amount ppm ~ approx. 210 wt ppm, approx. 1 wt ppm ~ approx. 205 wt ppm, approx. 1 wt ppm ~ approx. 200 wt ppm, approx. 1 wt ppm ~ approx. 195 wt ppm, approx. 1 wt ppm ~ approx. 190 wt ppm, approx. 1 wt ppm ~ approx. 185 Weight ppm, about 1 weight ppm to about 180 weight ppm, about 1 weight ppm to about 175 weight ppm, about 1 weight ppm to about 170 weight ppm, about 1 weight ppm to about 165 weight ppm, about 1 weight ppm to about 160 weight ppm, about 1 weight ppm Amount ppm ~ approx. 155 wt ppm, approx. 1 wt ppm ~ approx. 150 wt ppm, approx. 1 wt ppm ~ approx. 145 wt ppm, approx. 1 wt ppm ~ approx. 140 wt ppm, approx. 1 wt ppm ~ approx. 135 wt ppm, approx. 1 wt ppm ~ approx. 130 Weight ppm, about 1 weight ppm to about 125 weight ppm, about 1 weight ppm to about 120 weight ppm, about 1 weight ppm to about 115 weight ppm, about 1 weight ppm to about 110 weight ppm, about 1 weight ppm to about 105 weight ppm, about 1 weight ppm The glass may have a NaO content of from about 1 ppm to about 100 ppm by weight, from about 1 ppm to about 95 ppm by weight, from about 1 ppm to about 90 ppm by weight, from about 1 ppm to about 85 ppm by weight, from about 1 ppm to about 80 ppm by weight, from about 1 ppm to about 75 ppm by weight, from about 1 ppm to about 70 ppm by weight, from about 1 ppm to about 65 ppm by weight, from about 1 ppm to about 60 ppm by weight, from about 1 ppm to about 55 ppm by weight, or from about 1 ppm to about 50 ppm by weight. In one or more embodiments, glass sheets comprising such glasses, and consumer electronic products comprising such glass sheets, are described herein.

[0040] The glasses of the present disclosure can be used to produce glass articles, such as glass sheets and glass substrates, with excellent total pitch variability (TPV), as measured by three metrics: (1) compaction at high temperature test cycle (HTTC) of less than 40 ppm; (2) compaction at low temperature test cycle (LTTC) of less than 5.5 ppm, less than 1 ppm, and less than 0.5 ppm; and (3) stress relaxation rate, corresponding to less than 50% relaxation at stress relaxation test cycle (SRTC). Meeting all three criteria ensures that the glass substrate or glass article is acceptable for the manufacturing cycle of the highest resolution TFTs. In a specific embodiment, reducing the sodium content to less than 260 ppm affects the LTTC.

[0041] These test cycles are briefly described below.

[0042] High Temperature Test Cycle (HTTC) The samples are heat treated in a box furnace according to the thermal profile shown in Figure 1 of U.S. Patent Publication No. 2017 / 0144918. First, the furnace is preheated to a temperature slightly above 590°C. Next, a stack of five samples (four experimental samples and one control sample) is loaded into the furnace through a small slit in the front of the furnace. Thirty minutes after loading the samples into the furnace, the samples are removed from the furnace into ambient air and quenched. The total time the samples spend at the peak temperature of 590°C is approximately 18 minutes. For purposes of this disclosure, this test criterion will be defined as the High Temperature Test Cycle, or HTTC.

[0043] Low Temperature Test Cycle (LTTC) The magnitude of thermal compaction obtained from a typical TFT array or CF substrate thermal cycle is insufficient to perform reliable quality assurance measurements. A 450°C / 1-hour thermal cycle is used to achieve a larger compaction signal, allowing for identification of actual changes in performance. The furnace is held at a temperature slightly above 450°C prior to loading of the stack of five samples (four experimental and one control). The furnace requires approximately seven minutes of recovery time to this target hold temperature. After reaching the set point, the samples are held at 450°C for one hour, then removed and rapidly cooled to room temperature. An exemplary temperature trace is shown in Figure 2 of U.S. Patent Publication No. 2017 / 0144918. For purposes of this disclosure, this test criterion will be defined as the low temperature test cycle, or LTTC.

[0044] Stress Relaxation Test Cycle (SRTC) A glass plate sample was cut into a 10.00 mm wide crosspiece with a length greater than this width. The glass thickness was maintained at the as-formed thickness (0.5 mm to 0.7 mm). The glass sample was placed on two rigid supports placed in a resistance-heated electric furnace. An S-type thermocouple was placed near the center of the crosspiece, and the stress relaxation experiment was initiated by adjusting the position of the push rod. The span length of the two rigid supports was 88.90 mm. The lower end of the push rod was approximately 5 mm above the glass surface at room temperature. The furnace temperature was rapidly raised (within 5 to 10 minutes) to the final experimental temperature of 650 °C and allowed to idle at this temperature for approximately 5 to 5.5 minutes to achieve thermal equilibrium of all components placed inside the furnace. The push rod was lowered at a rate of 2.54 mm / min, and the experiment was continued by monitoring the load cell (LC) signal. This was done to determine contact between the push rod and the glass crosspiece. Once the LC signal reaches 0.1 lb (45.3592 g), the loading rate is accelerated to 10.16 mm / min. The load is stopped when the deflection at the center of the cross member reaches the final target value (e.g., 2.54 mm), and the program switches from stress-controlled mode to strain-controlled mode. The strain is held constant for the remainder of the experiment, but the stress is variable. The total time from initial contact between the push rod and the glass to the point at which the maximum strain of 2.54 mm is achieved is approximately 12 seconds. The experiment is terminated after collecting several hours of strain and stress versus time data.

[0045] Specific embodiments will now be provided.One embodiment is a glass comprising, on an oxide basis mole percent, 68.5-72.0 SiO, about 13.0 or more AlO, about 2.5 or less BO, 1.0-6.0 MgO, 4.0-8.0 CaO, about 4.5 or less SrO, and about 4.5 or less BaO, such that the ratio (MgO+CaO+SrO+BaO) / AlO is about 1.6 or less, wherein the glass has: an etch index of about 23 or greater; an annealing point of about 800°C or greater; Approx. 1 ppm to approx. 245 ppm, approx. 1 ppm to approx. 240 ppm, approx. 1 ppm to approx. 235 ppm, approx. 1 ppm to approx. 230 ppm, approx. 1 ppm to approx. 225 ppm, approx. 1 ppm to approx. 220 ppm, approx. 1 ppm to approx. 215 ppm m, about 1 wt ppm to about 210 wt ppm, about 1 wt ppm to about 205 wt ppm, about 1 wt ppm to about 200 wt ppm, about 1 wt ppm to about 195 wt ppm, about 1 wt ppm to about 190 wt ppm, about 1 wt ppm to about 185 wt ppm, about 1 wt ppm to about 180 wt ppm pm, about 1 wt ppm to about 175 wt ppm, about 1 wt ppm to about 170 wt ppm, about 1 wt ppm to about 165 wt ppm, about 1 wt ppm to about 160 wt ppm, about 1 wt ppm to about 155 wt ppm, about 1 wt ppm to about 150 wt ppm, about 1 wt ppm to about 145 wt Amount ppm, about 1 wt ppm to about 140 wt ppm, about 1 wt ppm to about 135 wt ppm, about 1 wt ppm to about 130 wt ppm, about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 11 the glass having a NaO content of 0 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight; and a Young's modulus of greater than 82 GPa.

[0046] One embodiment is a glass comprising, in mole percent on an oxide basis, 68.0-70.5 SiO2, 13.0-14.0 Al2O3, >0-3.0 B2O3, 0.9-9.0 MgO, 5.25-11 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, the glass being substantially alkali-free and having a Na2O content of 1 ppm to about 259 ppm by weight, about 1 ppm to about 255 ppm by weight, about 1 ppm to about 250 ppm by weight, about 1 ppm to about 245 ppm by weight, about ... ~240 ppm by weight, approximately 1 ppm by weight~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight pm, about 1 wt ppm to about 205 wt ppm, about 1 wt ppm to about 200 wt ppm, about 1 wt ppm to about 195 wt ppm, about 1 wt ppm to about 190 wt ppm, about 1 wt ppm to about 185 wt ppm, about 1 wt ppm to about 180 wt ppm, about 1 wt ppm m ~ about 175 wt ppm, about 1 wt ppm - about 170 wt ppm, about 1 wt ppm - about 165 wt ppm, about 1 wt ppm - about 160 wt ppm, about 1 wt ppm - about 155 wt ppm, about 1 wt ppm - about 150 wt ppm, about 1 wt ppm - about 145 wt ppm, about 1 wt ppm to about 140 wt ppm, about 1 wt ppm to about 135 wt ppm, about 1 wt ppm to about 130 wt ppm, about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm pm to about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and 3One embodiment relates to a glass comprising, in mole percent on an oxide basis, 63.0-75.0 SiO2, 13.0-14.0 Al2O3, >0-2.8 B2O3, 0.9-9.0 MgO, 5.25-11 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, wherein the glass is substantially alkali-free and has a Na2O content of 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 245 ppm by weight, about ...9 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 25 ~240 ppm by weight, approximately 1 ppm by weight~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight pm, about 1 wt ppm to about 205 wt ppm, about 1 wt ppm to about 200 wt ppm, about 1 wt ppm to about 195 wt ppm, about 1 wt ppm to about 190 wt ppm, about 1 wt ppm to about 185 wt ppm, about 1 wt ppm to about 180 wt ppm, about 1 wt ppm m ~ about 175 wt ppm, about 1 wt ppm - about 170 wt ppm, about 1 wt ppm - about 165 wt ppm, about 1 wt ppm - about 160 wt ppm, about 1 wt ppm - about 155 wt ppm, about 1 wt ppm - about 150 wt ppm, about 1 wt ppm - about 145 wt ppm, about 1 wt ppm to about 140 wt ppm, about 1 wt ppm to about 135 wt ppm, about 1 wt ppm to about 130 wt ppm, about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm pm to about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and 3 The present invention relates to a glass having an etching index of

[0047] One embodiment is a glass comprising, in mole percent on an oxide basis, 63.0-75.0 SiO2, 13.0-14.0 Al2O3, >0-3.0 B2O3, 0.9-9.0 MgO, 5.25-11 CaO, >0-6.0 SrO, and 3.0-5.4 BaO, the glass being substantially alkali-free and having a Na2O content of 1 ppm to about 259 ppm by weight, about 1 ppm to about 255 ppm by weight, about 1 ppm to about 250 ppm by weight, about 1 ppm to about 245 ppm by weight, about ... ~240 ppm by weight, approximately 1 ppm by weight~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight pm, about 1 wt ppm to about 205 wt ppm, about 1 wt ppm to about 200 wt ppm, about 1 wt ppm to about 195 wt ppm, about 1 wt ppm to about 190 wt ppm, about 1 wt ppm to about 185 wt ppm, about 1 wt ppm to about 180 wt ppm, about 1 wt ppm m ~ about 175 wt ppm, about 1 wt ppm - about 170 wt ppm, about 1 wt ppm - about 165 wt ppm, about 1 wt ppm - about 160 wt ppm, about 1 wt ppm - about 155 wt ppm, about 1 wt ppm - about 150 wt ppm, about 1 wt ppm - about 145 wt ppm, about 1 wt ppm to about 140 wt ppm, about 1 wt ppm to about 135 wt ppm, about 1 wt ppm to about 130 wt ppm, about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm pm to about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and 3 The present invention relates to a glass having an etching index of

[0048] One embodiment is a glass comprising, in mole percent on an oxide basis, 63.0-75.0 SiO2, 13.0-14.5 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.0-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, wherein the glass is substantially alkali-free and has a Na2O content of 1 ppm to about 259 ppm by weight, about 1 ppm to about 255 ppm by weight, about 1 ppm to about 250 ppm by weight, about 1 ppm to about 245 ppm by weight, or about 1 ppm to about 240 ppm by weight. m, about 1 wt ppm to about 235 wt ppm, about 1 wt ppm to about 230 wt ppm, about 1 wt ppm to about 225 wt ppm, about 1 wt ppm to about 220 wt ppm, about 1 wt ppm to about 215 wt ppm, about 1 wt ppm to about 210 wt ppm, about 1 wt ppm to about 20 5 ppm by weight, about 1 ppm to about 200 ppm by weight, about 1 ppm to about 195 ppm by weight, about 1 ppm to about 190 ppm by weight, about 1 ppm to about 185 ppm by weight, about 1 ppm to about 180 ppm by weight, about 1 ppm to about 175 ppm by weight, about 1 ppm by weight m ~ 170 ppm by weight, 1 ppm by weight ~ 165 ppm by weight, 1 ppm by weight ~ 160 ppm by weight, 1 ppm by weight ~ 155 ppm by weight, 1 ppm by weight ~ 150 ppm by weight, 1 ppm by weight ~ 145 ppm by weight, 1 ppm by weight ~ 140 ppm by weight, approx. 1 ppm by weight ~ approx. 135 ppm by weight, approx. 1 ppm by weight ~ approx. 130 ppm by weight, approx. 1 ppm by weight ~ approx. 125 ppm by weight, approx. 1 ppm by weight ~ approx. 120 ppm by weight, approx. 1 ppm by weight ~ approx. 115 ppm by weight, approx. ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, the ratio (MgO+CaO+SrO+BaO) / Al2O3 is 1.1 to 1.6, and 3The present invention relates to a glass having an etching index of

[0049] One embodiment is a glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.25-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, wherein the glass is substantially alkali-free and has a Na2O content of 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 245 ppm by weight, about ...55 ppm by weight, about 1 ppm by weight to about 25 m ~ approx. 240 wt ppm, approx. 1 wt ppm ~ approx. 235 wt ppm, approx. 1 wt ppm ~ approx. 230 wt ppm, approx. 1 wt ppm ~ approx. 225 wt ppm, approx. 1 wt ppm ~ approx. 220 wt ppm, approx. 1 wt ppm ~ approx. 215 wt ppm, approx. 1 wt ppm ~ approx. 210 wt ppm pm, about 1 wt ppm to about 205 wt ppm, about 1 wt ppm to about 200 wt ppm, about 1 wt ppm to about 195 wt ppm, about 1 wt ppm to about 190 wt ppm, about 1 wt ppm to about 185 wt ppm, about 1 wt ppm to about 180 wt ppm, about 1 wt ppm m ~ about 175 wt ppm, about 1 wt ppm - about 170 wt ppm, about 1 wt ppm - about 165 wt ppm, about 1 wt ppm - about 160 wt ppm, about 1 wt ppm - about 155 wt ppm, about 1 wt ppm - about 150 wt ppm, about 1 wt ppm - about 145 wt ppm, about 1 wt ppm to about 140 wt ppm, about 1 wt ppm to about 135 wt ppm, about 1 wt ppm to about 130 wt ppm, about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm pm to about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and3 The present invention relates to a glass having an etching index of

[0050] One embodiment is a glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.0-6.5 CaO, >0-6.0 SrO, and 3.5-4.0 BaO, the glass being substantially alkali-free and having a Na2O content of 1 ppm to about 259 ppm by weight, about 1 ppm to about 255 ppm by weight, about 1 ppm to about 250 ppm by weight, about 1 ppm to about 245 ppm by weight, about ...9 ppm by weight, about 1 ppm to about 255 ppm by weight, about 1 ppm to about 250 ppm by weight, about 1 ppm to about 245 ppm by weight, about 1 ppm to about 259 ppm by weight, about 1 ppm to about 259 ppm by weight, about 1 ppm to about 255 ppm by weight, about 1 ppm to about 250 ppm by weight, about 1 ppm to about 245 ppm by weight, about 1 ppm to about 259 ppm by weight, about 1 ppm to about 259 ppm by weight, about 1 ppm to ~240 ppm by weight, approximately 1 ppm by weight~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight pm, about 1 wt ppm to about 205 wt ppm, about 1 wt ppm to about 200 wt ppm, about 1 wt ppm to about 195 wt ppm, about 1 wt ppm to about 190 wt ppm, about 1 wt ppm to about 185 wt ppm, about 1 wt ppm to about 180 wt ppm, about 1 wt ppm m ~ about 175 wt ppm, about 1 wt ppm - about 170 wt ppm, about 1 wt ppm - about 165 wt ppm, about 1 wt ppm - about 160 wt ppm, about 1 wt ppm - about 155 wt ppm, about 1 wt ppm - about 150 wt ppm, about 1 wt ppm - about 145 wt ppm, about 1 wt ppm to about 140 wt ppm, about 1 wt ppm to about 135 wt ppm, about 1 wt ppm to about 130 wt ppm, about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm pm to about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and 3 The present invention relates to a glass having an etching index of

[0051] One embodiment is a glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.0-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, with the sum of CaO and BaO >8.6, wherein the glass is substantially alkali-free and has a Na2O content of 1 ppm to about 259 ppm by weight, about 1 ppm to about 255 ppm by weight, about 1 ppm to about 250 ppm by weight, or about 1 ppm to about 24 ppm by weight. 5 ppm by weight, about 1 ppm to about 240 ppm by weight, about 1 ppm to about 235 ppm by weight, about 1 ppm to about 230 ppm by weight, about 1 ppm to about 225 ppm by weight, about 1 ppm to about 220 ppm by weight, about 1 ppm to about 215 ppm by weight, about 1 ppm by weight ppm to approx. 210 ppm by weight, approx. 1 ppm to approx. 205 ppm by weight, approx. 1 ppm to approx. 200 ppm by weight, approx. 1 ppm to approx. 195 ppm by weight, approx. 1 ppm to approx. 190 ppm by weight, approx. 1 ppm to approx. 185 ppm by weight, approx. pm, about 1 wt ppm to about 175 wt ppm, about 1 wt ppm to about 170 wt ppm, about 1 wt ppm to about 165 wt ppm, about 1 wt ppm to about 160 wt ppm, about 1 wt ppm to about 155 wt ppm, about 1 wt ppm to about 150 wt ppm, about 1 wt ppm~ Approx. 145 ppm by weight, approx. 1 ppm to approx. 140 ppm, approx. 1 ppm to approx. 135 ppm, approx. 1 ppm to approx. 130 ppm, approx. 1 ppm to approx. 125 ppm, approx. 1 ppm to approx. 120 ppm, approx. 1 ppm by weight to about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and 3 The present invention relates to a glass having an etching index of

[0052] Some embodiments include: Annealing temperatures above approximately 785°C; Density of approximately 2.65 g / cc or less; T below approximately 1750°C 200P ; T below approximately 1340°C 35kP ; A Young's modulus of approximately 82 GPa or greater; and The following equation: -54.6147+(2.50004)*(Al2O3)+(1.3134)*(B2O3)+(1.84106)*(MgO)+(3.01223)*(CaO)+(3.7248)*(SrO)+(4.13149)*(BaO), Defined as approximately 21 μm / mm 3 Etching index above The glass is substantially alkali-free and has a NaO content of 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 245 ppm by weight, about 1 ppm by weight to about 240 ppm by weight, about 1 ppm by weight to about 235 ppm by weight, about 1 ppm by weight to about 230 ppm by weight, about 1 ppm by weight to about 225 ppm by weight, about 1 ppm by weight to about 220 ppm by weight, Approx. 1 ppm to approx. 215 ppm by weight, approx. 1 ppm to approx. 210 ppm by weight, approx. 1 ppm to approx. 205 ppm by weight, approx. 1 ppm to approx. 200 ppm by weight, approx. 1 ppm to approx. 195 ppm by weight, approx. 1 ppm to approx. 190 Weight ppm, about 1 weight ppm to about 185 weight ppm, about 1 weight ppm to about 180 weight ppm, about 1 weight ppm to about 175 weight ppm, about 1 weight ppm to about 170 weight ppm, about 1 weight ppm to about 165 weight ppm, about 1 weight ppm ~160 ppm by weight, ~155 ppm by weight, ~150 ppm by weight, ~145 ppm by weight, ~1 ppm by weight~140 ppm by weight, ~1 ppm by weight~135 ppm by weight, approx. 1 ppm by weight ~ approx. 130 ppm by weight, approx. 1 ppm by weight ~ approx. 125 ppm by weight, approx. 1 ppm by weight ~ approx. 120 ppm by weight, approx. 1 ppm by weight ~ approx. 115 ppm by weight, approx. 1 ppm by weight ~ approx. 110 ppm by weight, approx. ppm by weight, about 1 ppm to about 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight.

[0053] One embodiment is a substantially alkali-free glass comprising, in mole percent on an oxide basis, 69.76-71.62 SiO, 11.03-13.57 AlO, 0-2.99 BO, 3.15-5.84 MgO, 4.55-7.35 CaO, 0.2-1.99 SrO, 2.61-4.41 BaO, and 0-1.0 ZnO, wherein the ratio (MgO+CaO+SrO+BaO) / AlO is about 1.0-1.6, and the NaO content is 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about ... 50 ppm by weight, about 1 ppm to about 245 ppm by weight, about 1 ppm to about 240 ppm by weight, about 1 ppm to about 235 ppm by weight, about 1 ppm to about 230 ppm by weight, about 1 ppm to about 225 ppm by weight, about 1 ppm to about 220 ppm by weight, about 1 ppm to approx. 215 ppm by weight, approximately 1 ppm by weight ~ approximately 210 ppm by weight, approximately 1 ppm by weight ~ approximately 205 ppm by weight, approximately 1 ppm by weight ~ approximately 200 ppm by weight, approximately 1 ppm by weight ~ approximately 195 ppm by weight, approximately 1 ppm by weight ~ approximately 190 ppm by weight, approximately 1 ppm by weight ~ approximately 185 ppm by weight, approximately 1 ppm by weight ~ Approx. 180 ppm by weight, approx. 1 ppm to approx. 175 ppm, approx. 1 ppm to approx. 170 ppm, approx. 1 ppm to approx. 165 ppm, approx. 1 ppm to approx. 160 ppm, approx. 1 ppm to approx. 155 ppm, approx. 1 ppm to approx. 150 ppm, approx. 1 ppm by weight ~145 ppm by weight, approximately 1 ppm by weight~140 ppm by weight, approximately 1 ppm by weight~135 ppm by weight, approximately 1 ppm by weight~130 ppm by weight, approximately 1 ppm by weight~approximately 125 ppm by weight, approximately 1 ppm by weight~approximately 120 ppm by weight, approximately 1 ppm by weight~approximately 115 ppm by weight, approximately 1 ppm by weight The MgO / (MgO+CaO+SrO+BaO) ratio is about 0.5 to about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight.22 to 0.37, for glass.

[0054] One embodiment is a substantially alkali-free glass comprising, in mole percent on an oxide basis, 68.14-72.29 SiO, 11.03-14.18 AlO, 0-2.99 BO, 1.09-7.2 MgO, 4.12-9.97 CaO, 0.2-4.15 SrO, 1.26-4.41 BaO, and 0-1.0 ZnO, wherein the ratio (MgO+CaO+SrO+BaO) / AlO is about 1.0-1.6, and the NaO content is from about 259 ppm by weight, from about 1 ppm by weight to about 255 ppm by weight, from about 1 ppm by weight to about 25 ppm by weight, or from about 1 ppm by weight to about 25 ppm by weight. 0 ppm by weight, about 1 ppm to about 245 ppm by weight, about 1 ppm to about 240 ppm by weight, about 1 ppm to about 235 ppm by weight, about 1 ppm to about 230 ppm by weight, about 1 ppm to about 225 ppm by weight, about 1 ppm to about 220 ppm by weight, about 1 ppm to about 2 15 wt ppm, about 1 wt ppm to about 210 wt ppm, about 1 wt ppm to about 205 wt ppm, about 1 wt ppm to about 200 wt ppm, about 1 wt ppm to about 195 wt ppm, about 1 wt ppm to about 190 wt ppm, about 1 wt ppm to about 185 wt ppm, about 1 wt ppm to about 180 ppm by weight, about 1 ppm to about 175 ppm by weight, about 1 ppm to about 170 ppm by weight, about 1 ppm to about 165 ppm by weight, about 1 ppm to about 160 ppm by weight, about 1 ppm to about 155 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm by weight Approx. 145 ppm by weight, approx. 1 ppm to approx. 140 ppm, approx. 1 ppm to approx. 135 ppm, approx. 1 ppm to approx. 130 ppm, approx. 1 ppm to approx. 125 ppm, approx. 1 ppm to approx. 120 ppm, approx. 1 ppm to approx. 115 ppm, approx. 1 ppm by weight to about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and the ratio of MgO / (MgO+CaO+SrO+BaO) is about 0.22 to 0.37, for glass.

[0055] Some embodiments are substantially alkali-free glasses having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0-1.6, a ratio of MgO / (MgO+CaO+SrO+BaO) of about 0.22-0.37, a T(ann)>785°C, a density <2.65 g / cc, a T(200P)<1750°C, a T(350)<1340°C, a Young's modulus >82 GPa, and a Na2O content of 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, or about 1 ppm by weight to about 250 ppm by weight. m, about 1 wt ppm to about 245 wt ppm, about 1 wt ppm to about 240 wt ppm, about 1 wt ppm to about 235 wt ppm, about 1 wt ppm to about 230 wt ppm, about 1 wt ppm to about 225 wt ppm, about 1 wt ppm to about 220 wt ppm, about 1 wt ppm to about 215 Weight ppm, about 1 weight ppm to about 210 weight ppm, about 1 weight ppm to about 205 weight ppm, about 1 weight ppm to about 200 weight ppm, about 1 weight ppm to about 195 weight ppm, about 1 weight ppm to about 190 weight ppm, about 1 weight ppm to about 185 weight ppm, about 1 weight ppm ~ Approx. 180 ppm by weight, approx. 1 ppm to approx. 175 ppm, approx. 1 ppm to approx. 170 ppm, approx. 1 ppm to approx. 165 ppm, approx. 1 ppm to approx. 160 ppm, approx. 1 ppm to approx. 155 ppm, approx. 1 ppm to approx. 150 ppm, approx. ppm to about 145 weight ppm, about 1 weight ppm to about 140 weight ppm, about 1 weight ppm to about 135 weight ppm, about 1 weight ppm to about 130 weight ppm, about 1 weight ppm to about 125 weight ppm, about 1 weight ppm to about 120 weight ppm, about 1 weight ppm to about 115 weight ppm, about 1 ppm by weight to about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and an etching index of >21 μm / mm 3 This is about glass.

[0056] Some embodiments are substantially alkali-free glasses, having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to 1.6, a ratio MgO / (MgO+CaO+SrO+BaO) of about 0.22 to 0.37, and a Na2O content of 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 245 ppm by weight, about 1 ppm by weight to about 240 ppm by weight, about 1 ppm by weight to about 235 ... ppm to approx. 230 ppm by weight, approx. 1 ppm to approx. 225 ppm by weight, approx. 1 ppm to approx. 220 ppm by weight, approx. 1 ppm to approx. 215 ppm by weight, approx. 1 ppm to approx. 210 ppm by weight, approx. 1 ppm to approx. 205 ppm by weight, approx. Approx. 200 ppm by weight, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. 185 ppm, approx. 1 ppm to approx. 180 ppm, approx. 1 ppm to approx. 175 ppm, approx. 1 ppm to approx. Weight ppm, about 1 weight ppm to about 165 weight ppm, about 1 weight ppm to about 160 weight ppm, about 1 weight ppm to about 155 weight ppm, about 1 weight ppm to about 150 weight ppm, about 1 weight ppm to about 145 weight ppm, about 1 weight ppm to about 140 weight ppm m, about 1 wt ppm to about 135 wt ppm, about 1 wt ppm to about 130 wt ppm, about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and an etching index of >21 μm / mm 3 This is about glass.

[0057] Some embodiments are substantially alkali-free glasses, having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to 1.6, a ratio MgO / (MgO+CaO+SrO+BaO) of about 0.22 to 0.37, and a Na2O content of 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 245 ppm by weight, about 1 ppm by weight to about 240 ppm by weight, about 1 ppm by weight to about 235 ppm by weight, about ... pm ~ about 230 weight ppm, about 1 weight ppm - about 225 weight ppm, about 1 weight ppm - about 220 weight ppm, about 1 weight ppm - about 215 weight ppm, about 1 weight ppm - about 210 weight ppm, about 1 weight ppm - about 205 weight ppm, about 1 weight ppm - about 2 00 ppm by weight, about 1 ppm to about 195 ppm by weight, about 1 ppm to about 190 ppm by weight, about 1 ppm to about 185 ppm by weight, about 1 ppm to about 180 ppm by weight, about 1 ppm to about 175 ppm by weight, about 1 ppm to about 170 ppm by weight pm, about 1 wt ppm to about 165 wt ppm, about 1 wt ppm to about 160 wt ppm, about 1 wt ppm to about 155 wt ppm, about 1 wt ppm to about 150 wt ppm, about 1 wt ppm to about 145 wt ppm, about 1 wt ppm to about 140 wt ppm, about 1 Weight ppm to approx. 135 weight ppm, approx. 1 weight ppm to approx. 130 weight ppm, approx. 1 weight ppm to approx. 125 weight ppm, approx. 1 weight ppm to approx. 120 weight ppm, approx. 1 weight ppm to approx. 115 weight ppm, approx. 1 weight ppm to approx. 110 weight ppm, approx. 1 weight ppm to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and a liquidus viscosity of >150 kP.

[0058] One embodiment is a substantially alkali-free glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to about 1.6 and an etching index of 21 μm / mm 3 or more, T(ann)>800°C, and the NaO content is 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 245 ppm by weight, about 1 ppm by weight to about 240 ppm by weight, about 1 ppm by weight to about 235 ppm by weight, about 1 ppm by weight to about 230 ppm by weight, about 1 ppm by weight to about 225 ppm by weight, about 1 ppm by weight to about 220 ppm by weight, about 1 ppm by weight to about 215 ppm by weight ppm, approx. 1 ppm to approx. 210 ppm, approx. 1 ppm to approx. 205 ppm, approx. 1 ppm to approx. 200 ppm, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. Approx. 185 ppm by weight, approx. 1 ppm to approx. 180 ppm by weight, approx. 1 ppm to approx. 175 ppm by weight, approx. 1 ppm to approx. 170 ppm by weight, approx. 1 ppm to approx. 165 ppm by weight, approx. 1 ppm to approx. 160 ppm by weight, approx. 1 ppm by weight Amount ppm ~ approx. 155 wt ppm, approx. 1 wt ppm ~ approx. 150 wt ppm, approx. 1 wt ppm ~ approx. 145 wt ppm, approx. 1 wt ppm ~ approx. 140 wt ppm, approx. 1 wt ppm ~ approx. 135 wt ppm, approx. 1 wt ppm ~ approx. 130 wt ppm pm, about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 wt ppm to about 105 wt ppm, about 1 wt ppm to about 1 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight, and a Young's modulus >82 GPa.

[0059] Some embodiments are directed to a substantially alkali-free aluminosilicate glass article, the glass article comprising: Annealing temperatures above approximately 795°C; Density of approximately 2.63 g / cc or less; T below approximately 1730°C 200P ; T below approximately 1320°C 35kP ; Young's modulus of approximately 81.5 GPa or more; 1 wt ppm ~ approx. 259 wt ppm, approx. 1 wt ppm ~ approx. 255 wt ppm, approx. 1 wt ppm ~ approx. 250 wt ppm, approx. 1 wt ppm ~ approx. 245 wt ppm, approx. 1 wt ppm ~ approx. 240 wt ppm, approx. 1 wt ppm ~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight ppm, approx. 1 ppm to approx. 205 ppm, approx. 1 ppm to approx. 200 ppm, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. 185 ppm, approx. 1 ppm by weight Amount ppm ~ approx. 180 wt ppm, approx. 1 wt ppm ~ approx. 175 wt ppm, approx. 1 wt ppm ~ approx. 170 wt ppm, approx. 1 wt ppm ~ approx. 165 wt ppm, approx. 1 wt ppm ~ approx. 160 wt ppm, approx. 1 wt ppm ~ approx. 1 55 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm to about 145 ppm by weight, about 1 ppm to about 140 ppm by weight, about 1 ppm to about 135 ppm by weight, about 1 ppm to about 130 ppm by weight , about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 wt ppm to about 105 wt ppm, about 1 wt ppm a NaO content of about 1 ppm to about 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight; and Approximately 23μm / mm 3 Etching index above The present invention relates to an aluminosilicate glass article having the following structure:

[0060] Some embodiments are directed to a substantially alkali-free aluminosilicate glass article, the glass article comprising: Annealing temperatures above approximately 800°C; Density of approximately 2.61 g / cc or less; T below approximately 1710°C 200P ; T below approximately 1310°C 35kP ; Young's modulus of approximately 81.2 GPa or more; 1 wt ppm ~ approx. 259 wt ppm, approx. 1 wt ppm ~ approx. 255 wt ppm, approx. 1 wt ppm ~ approx. 250 wt ppm, approx. 1 wt ppm ~ approx. 245 wt ppm, approx. 1 wt ppm ~ approx. 240 wt ppm, approx. 1 wt ppm ~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight ppm, approx. 1 ppm to approx. 205 ppm, approx. 1 ppm to approx. 200 ppm, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. 185 ppm, approx. 1 ppm by weight Amount ppm ~ approx. 180 wt ppm, approx. 1 wt ppm ~ approx. 175 wt ppm, approx. 1 wt ppm ~ approx. 170 wt ppm, approx. 1 wt ppm ~ approx. 165 wt ppm, approx. 1 wt ppm ~ approx. 160 wt ppm, approx. 1 wt ppm ~ approx. 1 55 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm to about 145 ppm by weight, about 1 ppm to about 140 ppm by weight, about 1 ppm to about 135 ppm by weight, about 1 ppm to about 130 ppm by weight , about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 wt ppm to about 105 wt ppm, about 1 wt ppm a NaO content of about 1 ppm to about 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight; and Approximately 23μm / mm 3 Etching index above The present invention relates to an aluminosilicate glass article having the following structure:

[0061] Some embodiments include: T above approximately 1270°C 35kP ; SnO2 concentration of about 0.001 mol% to 0.5 mol%; 1 wt ppm ~ approx. 259 wt ppm, approx. 1 wt ppm ~ approx. 255 wt ppm, approx. 1 wt ppm ~ approx. 250 wt ppm, approx. 1 wt ppm ~ approx. 245 wt ppm, approx. 1 wt ppm ~ approx. 240 wt ppm, approx. 1 wt ppm ~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight ppm, approx. 1 ppm to approx. 205 ppm, approx. 1 ppm to approx. 200 ppm, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. 185 ppm, approx. 1 ppm by weight Amount ppm ~ approx. 180 wt ppm, approx. 1 wt ppm ~ approx. 175 wt ppm, approx. 1 wt ppm ~ approx. 170 wt ppm, approx. 1 wt ppm ~ approx. 165 wt ppm, approx. 1 wt ppm ~ approx. 160 wt ppm, approx. 1 wt ppm ~ approx. 1 55 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm to about 145 ppm by weight, about 1 ppm to about 140 ppm by weight, about 1 ppm to about 135 ppm by weight, about 1 ppm to about 130 ppm by weight , about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 wt ppm to about 105 wt ppm, about 1 wt ppm a NaO content of about 1 ppm to about 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight; and Approximately 21μm / mm 3 Etching index above The present invention relates to a glass having the formula:

[0062] Some embodiments include: T above approximately 1650°C 200P ; SnO2 concentration of about 0.001 mol% to 0.5 mol%; 1 wt ppm ~ approx. 259 wt ppm, approx. 1 wt ppm ~ approx. 255 wt ppm, approx. 1 wt ppm ~ approx. 250 wt ppm, approx. 1 wt ppm ~ approx. 245 wt ppm, approx. 1 wt ppm ~ approx. 240 wt ppm, approx. 1 wt ppm ~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight ppm, approx. 1 ppm to approx. 205 ppm, approx. 1 ppm to approx. 200 ppm, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. 185 ppm, approx. 1 ppm by weight Amount ppm ~ approx. 180 wt ppm, approx. 1 wt ppm ~ approx. 175 wt ppm, approx. 1 wt ppm ~ approx. 170 wt ppm, approx. 1 wt ppm ~ approx. 165 wt ppm, approx. 1 wt ppm ~ approx. 160 wt ppm, approx. 1 wt ppm ~ approx. 1 55 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm to about 145 ppm by weight, about 1 ppm to about 140 ppm by weight, about 1 ppm to about 135 ppm by weight, about 1 ppm to about 130 ppm by weight , about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 wt ppm to about 105 wt ppm, about 1 wt ppm a NaO content of about 1 ppm to about 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight; and Approximately 21μm / mm 3 Etching index above The present invention relates to a glass having the formula:

[0063] Some embodiments include: Liquidus temperature above about 1150°C; SnO2 concentration of about 0.001 mol% to 0.5 mol%; 1 wt ppm ~ approx. 259 wt ppm, approx. 1 wt ppm ~ approx. 255 wt ppm, approx. 1 wt ppm ~ approx. 250 wt ppm, approx. 1 wt ppm ~ approx. 245 wt ppm, approx. 1 wt ppm ~ approx. 240 wt ppm, approx. 1 wt ppm ~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight ppm, approx. 1 ppm to approx. 205 ppm, approx. 1 ppm to approx. 200 ppm, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. 185 ppm, approx. 1 ppm by weight Amount ppm ~ approx. 180 wt ppm, approx. 1 wt ppm ~ approx. 175 wt ppm, approx. 1 wt ppm ~ approx. 170 wt ppm, approx. 1 wt ppm ~ approx. 165 wt ppm, approx. 1 wt ppm ~ approx. 160 wt ppm, approx. 1 wt ppm ~ approx. 1 55 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm to about 145 ppm by weight, about 1 ppm to about 140 ppm by weight, about 1 ppm to about 135 ppm by weight, about 1 ppm to about 130 ppm by weight , about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 wt ppm to about 105 wt ppm, about 1 wt ppm a NaO content of about 1 ppm to about 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight; and Approximately 21μm / mm 3 Etching index above The present invention relates to a glass having the formula:

[0064] Some embodiments include: T above approximately 1270°C 35kP ; 1 wt ppm ~ approx. 259 wt ppm, approx. 1 wt ppm ~ approx. 255 wt ppm, approx. 1 wt ppm ~ approx. 250 wt ppm, approx. 1 wt ppm ~ approx. 245 wt ppm, approx. 1 wt ppm ~ approx. 240 wt ppm, approx. 1 wt ppm ~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight ppm, approx. 1 ppm to approx. 205 ppm, approx. 1 ppm to approx. 200 ppm, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. 185 ppm, approx. 1 ppm by weight Amount ppm ~ approx. 180 wt ppm, approx. 1 wt ppm ~ approx. 175 wt ppm, approx. 1 wt ppm ~ approx. 170 wt ppm, approx. 1 wt ppm ~ approx. 165 wt ppm, approx. 1 wt ppm ~ approx. 160 wt ppm, approx. 1 wt ppm ~ approx. 1 55 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm to about 145 ppm by weight, about 1 ppm to about 140 ppm by weight, about 1 ppm to about 135 ppm by weight, about 1 ppm to about 130 ppm by weight , about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 wt ppm to about 105 wt ppm, about 1 wt ppm a NaO content of about 1 ppm to about 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight; and SnO2 concentration of approximately 0.001 mol% to 0.5 mol% The present invention relates to a glass having the formula:

[0065] Some embodiments include: T above approximately 1650°C 200P ; 1 wt ppm ~ approx. 259 wt ppm, approx. 1 wt ppm ~ approx. 255 wt ppm, approx. 1 wt ppm ~ approx. 250 wt ppm, approx. 1 wt ppm ~ approx. 245 wt ppm, approx. 1 wt ppm ~ approx. 240 wt ppm, approx. 1 wt ppm ~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight ppm, approx. 1 ppm to approx. 205 ppm, approx. 1 ppm to approx. 200 ppm, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. 185 ppm, approx. 1 ppm by weight Amount ppm ~ approx. 180 wt ppm, approx. 1 wt ppm ~ approx. 175 wt ppm, approx. 1 wt ppm ~ approx. 170 wt ppm, approx. 1 wt ppm ~ approx. 165 wt ppm, approx. 1 wt ppm ~ approx. 160 wt ppm, approx. 1 wt ppm ~ approx. 1 55 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm to about 145 ppm by weight, about 1 ppm to about 140 ppm by weight, about 1 ppm to about 135 ppm by weight, about 1 ppm to about 130 ppm by weight , about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 wt ppm to about 105 wt ppm, about 1 wt ppm a NaO content of about 1 ppm to about 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight; and SnO2 concentration of approximately 0.001 mol% to 0.5 mol% The present invention relates to a glass having the formula:

[0066] Some embodiments include: Annealing temperatures above approximately 785°C; Young's modulus of approximately 81 GPa or more; T below approximately 1750°C 200P ; T below approximately 1340°C35kP ; 1 wt ppm ~ approx. 259 wt ppm, approx. 1 wt ppm ~ approx. 255 wt ppm, approx. 1 wt ppm ~ approx. 250 wt ppm, approx. 1 wt ppm ~ approx. 245 wt ppm, approx. 1 wt ppm ~ approx. 240 wt ppm, approx. 1 wt ppm ~235 ppm by weight, approximately 1 ppm by weight~230 ppm by weight, approximately 1 ppm by weight~225 ppm by weight, approximately 1 ppm by weight~220 ppm by weight, approximately 1 ppm by weight~215 ppm by weight, approximately 1 ppm by weight~210 ppm by weight ppm, approx. 1 ppm to approx. 205 ppm, approx. 1 ppm to approx. 200 ppm, approx. 1 ppm to approx. 195 ppm, approx. 1 ppm to approx. 190 ppm, approx. 1 ppm to approx. 185 ppm, approx. 1 ppm by weight Amount ppm ~ approx. 180 wt ppm, approx. 1 wt ppm ~ approx. 175 wt ppm, approx. 1 wt ppm ~ approx. 170 wt ppm, approx. 1 wt ppm ~ approx. 165 wt ppm, approx. 1 wt ppm ~ approx. 160 wt ppm, approx. 1 wt ppm ~ approx. 1 55 ppm by weight, about 1 ppm to about 150 ppm by weight, about 1 ppm to about 145 ppm by weight, about 1 ppm to about 140 ppm by weight, about 1 ppm to about 135 ppm by weight, about 1 ppm to about 130 ppm by weight , about 1 wt ppm to about 125 wt ppm, about 1 wt ppm to about 120 wt ppm, about 1 wt ppm to about 115 wt ppm, about 1 wt ppm to about 110 wt ppm, about 1 wt ppm to about 105 wt ppm, about 1 wt ppm a NaO content of about 1 ppm to about 100 ppm by weight, about 1 ppm to about 95 ppm by weight, about 1 ppm to about 90 ppm by weight, about 1 ppm to about 85 ppm by weight, about 1 ppm to about 80 ppm by weight, about 1 ppm to about 75 ppm by weight, about 1 ppm to about 70 ppm by weight, about 1 ppm to about 65 ppm by weight, about 1 ppm to about 60 ppm by weight, about 1 ppm to about 55 ppm by weight, or about 1 ppm to about 50 ppm by weight; and Average surface roughness measured by atomic force microscope of less than 0.5 nm The present invention relates to a glass having the formula:

[0067] In one embodiment, there is provided a glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to 1.6, T(ann)>785°C, density<2.7 g / cc, T(200P)<1750°C, T(35 kP)>1270°C, Young's modulus>81 GPa, and a Na2O content of 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 245 ppm by weight, about 1 ppm by weight to about 240 ppm by weight, Approx. 1 ppm to approx. 235 ppm by weight, approx. 1 ppm to approx. 230 ppm, approx. 1 ppm to approx. 225 ppm, approx. 1 ppm to approx. 220 ppm, approx. 1 ppm to approx. 215 ppm, approx. 1 ppm to approx. 210 ppm, approx. 1 ppm by weight m ~ about 205 weight ppm, about 1 weight ppm - about 200 weight ppm, about 1 weight ppm - about 195 weight ppm, about 1 weight ppm - about 190 weight ppm, about 1 weight ppm - about 185 weight ppm, about 1 weight ppm - about 180 weight ppm, about 1 weight ppm - about 175 weight Amount ppm, about 1 wt ppm to about 170 wt ppm, about 1 wt ppm to about 165 wt ppm, about 1 wt ppm to about 160 wt ppm, about 1 wt ppm to about 155 wt ppm, about 1 wt ppm to about 150 wt ppm, about 1 wt ppm to about 145 wt ppm, about 1 wt ppm ~ approx. 140 wt ppm, approx. 1 wt ppm ~ approx. 135 wt ppm, approx. 1 wt ppm ~ approx. 130 wt ppm, approx. 1 wt ppm ~ approx. 125 wt ppm, approx. 1 wt ppm ~ approx. 120 wt ppm, approx. 1 wt ppm ~ approx. about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight.

[0068] One embodiment is a glass sheet comprising SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, wherein R0 / (B2O3+Al2O3) is 0.5 to 1.1, and the Na2O content is 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 245 ppm by weight, about 1 ppm by weight to about 240 ppm by weight, about 1 ppm by weight to about 235 ppm by weight, or about 1 ppm by weight to about 230 ppm by weight. m, about 1 wt ppm to about 225 wt ppm, about 1 wt ppm to about 220 wt ppm, about 1 wt ppm to about 215 wt ppm, about 1 wt ppm to about 210 wt ppm, about 1 wt ppm to about 205 wt ppm, about 1 wt ppm to about 200 wt ppm, about 1 wt ppm ~195 ppm by weight, approx. 1 ppm by weight~approximately 190 ppm by weight, approx. 1 ppm by weight~approximately 185 ppm by weight, approx. 1 ppm by weight~approximately 180 ppm by weight, approx. 1 ppm by weight~approximately 175 ppm by weight, approx. m, about 1 wt ppm to about 160 wt ppm, about 1 wt ppm to about 155 wt ppm, about 1 wt ppm to about 150 wt ppm, about 1 wt ppm to about 145 wt ppm, about 1 wt ppm to about 140 wt ppm, about 1 wt ppm to about 135 wt ppm, about 1 wt ppm m ~ about 130 wt ppm, about 1 wt ppm - about 125 wt ppm, about 1 wt ppm - about 120 wt ppm, about 1 wt ppm - about 115 wt ppm, about 1 wt ppm - about 110 wt ppm, about 1 wt ppm - about 105 wt ppm, about 1 wt ppm - about 100 wt ppm pm, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight, and BaO / RO is 0.22 to 1, where RO = (MgO + CaO + SrO + BaO).

[0069] In one embodiment, there is provided a glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to 1.6, T(ann)>785°C, density<2.7 g / cc, T(200P)<1750°C, T(35 kP)>1270°C, Young's modulus>81 GPa, and a Na2O content of 1 ppm by weight to about 259 ppm by weight, about 1 ppm by weight to about 255 ppm by weight, about 1 ppm by weight to about 250 ppm by weight, about 1 ppm by weight to about 245 ppm by weight, about 1 ppm by weight to about 240 ppm by weight, Approx. 1 ppm to approx. 235 ppm by weight, approx. 1 ppm to approx. 230 ppm, approx. 1 ppm to approx. 225 ppm, approx. 1 ppm to approx. 220 ppm, approx. 1 ppm to approx. 215 ppm, approx. 1 ppm to approx. 210 ppm, approx. 1 ppm by weight m ~ about 205 weight ppm, about 1 weight ppm - about 200 weight ppm, about 1 weight ppm - about 195 weight ppm, about 1 weight ppm - about 190 weight ppm, about 1 weight ppm - about 185 weight ppm, about 1 weight ppm - about 180 weight ppm, about 1 weight ppm - about 175 weight Amount ppm, about 1 wt ppm to about 170 wt ppm, about 1 wt ppm to about 165 wt ppm, about 1 wt ppm to about 160 wt ppm, about 1 wt ppm to about 155 wt ppm, about 1 wt ppm to about 150 wt ppm, about 1 wt ppm to about 145 wt ppm, about 1 wt ppm ~ approx. 140 wt ppm, approx. 1 wt ppm ~ approx. 135 wt ppm, approx. 1 wt ppm ~ approx. 130 wt ppm, approx. 1 wt ppm ~ approx. 125 wt ppm, approx. 1 wt ppm ~ approx. 120 wt ppm, approx. 1 wt ppm ~ approx. about 110 ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight.

[0070] One embodiment is a glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-3.0 B2O3, 0.9-9.0 MgO, 5.25-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, the glass being substantially alkali-free and having an alkali content of from 1 ppm to about 259 ppm by weight, from about 1 ppm to about 255 ppm by weight, from about 1 ppm to about 250 ppm by weight, from about 1 ppm to about 245 ppm by weight, or from about 1 ppm to about 240 ppm by weight. pm, about 1 wt ppm to about 235 wt ppm, about 1 wt ppm to about 230 wt ppm, about 1 wt ppm to about 225 wt ppm, about 1 wt ppm to about 220 wt ppm, about 1 wt ppm to about 215 wt ppm, about 1 wt ppm to about 210 wt ppm, about 1 wt ppm pm ~ approx. 205 wt ppm, approx. 1 wt ppm ~ approx. 200 wt ppm, approx. 1 wt ppm ~ approx. 195 wt ppm, approx. 1 wt ppm ~ approx. 190 wt ppm, approx. 1 wt ppm ~ approx. 185 wt ppm, approx. 1 wt ppm ~ approx. 180 wt ppm, approx. ppm, about 1 wt ppm to about 170 wt ppm, about 1 wt ppm to about 165 wt ppm, about 1 wt ppm to about 160 wt ppm, about 1 wt ppm to about 155 wt ppm, about 1 wt ppm to about 150 wt ppm, about 1 wt ppm to about 145 wt ppm, about 1 wt ppm to approx. 140 ppm by weight, approx. 1 ppm to approx. 135 ppm by weight, approx. 1 ppm to approx. 130 ppm by weight, approx. 1 ppm to approx. 125 ppm by weight, approx. 1 ppm to approx. 120 ppm by weight, approx. 1 ppm to approx. 115 ppm by weight, approx. ppm by weight, about 1 ppm by weight to about 105 ppm by weight, about 1 ppm by weight to about 100 ppm by weight, about 1 ppm by weight to about 95 ppm by weight, about 1 ppm by weight to about 90 ppm by weight, about 1 ppm by weight to about 85 ppm by weight, about 1 ppm by weight to about 80 ppm by weight, about 1 ppm by weight to about 75 ppm by weight, about 1 ppm by weight to about 70 ppm by weight, about 1 ppm by weight to about 65 ppm by weight, about 1 ppm by weight to about 60 ppm by weight, about 1 ppm by weight to about 55 ppm by weight, or about 1 ppm by weight to about 50 ppm by weight; 3 The present invention relates to a glass having an etching index of

[0071] In another embodiment, the temperature at which the exemplary glass reaches a viscosity of about 35,000 poise (T 35k ) is less than or equal to about 1340°C, 1335°C, 1330°C, 1325°C, 1320°C, 1315°C, 1310°C, 1300°C, or 1290°C. In specific embodiments, the glass has a viscosity of about 35,000 poise (T 35k ) is less than about 1310°C. In other embodiments, the temperature at which the viscosity of the exemplary glasses reaches about 35,000 poise (T 35k ) is less than about 1340°C, 1335°C, 1330°C, 1325°C, 1320°C, 1315°C, 1310°C, 1300°C, or 1290°C. In various embodiments, the glass article has a T of from about 1275°C to about 1340°C, or from about 1280°C to about 1315°C. 35k It has.

[0072] The liquidus temperature of glass (T liq ) is the temperature above which crystalline phases cannot coexist in equilibrium with the glass. In various embodiments, the glass article can be heated to a T of about 1180°C to about 1290°C, or about 1190°C to about 1280°C. liq In another embodiment, the viscosity corresponding to the liquidus temperature of the glass is greater than or equal to about 150,000 poise. In some embodiments, the viscosity corresponding to the liquidus temperature of the glass is greater than or equal to about 175,000 poise, 200,000 poise, 225,000 poise, or 250,000 poise.

[0073] In another embodiment, the exemplary glass is T 35k -T liq >0.25T 35k It can provide temperatures of -225°C, which ensures that there is minimal tendency for devitrification to occur on the forming mandrel of the fusion process.

[0074] In one or more embodiments, the substantially alkali-free glass comprises, in mole percent on an oxide basis: 60~80 SiO2 5-20 Al2O3 0-10 B2O3 0-20 MgO 0-20 CaO 0-20 SrO 0-20 BaO 0-20 ZnO where Al2O3, MgO, CaO, SrO, and BaO represent the mole percentage of each oxide component.

[0075] In some embodiments, the substantially alkali-free glass comprises, in mole percent on an oxide basis: SiO2 65~75 SiO2 10-15 Al2O3 0 to 3.5 B2O3 0 to 7.5 MgO 4 to 10 CaO 0-5 SrO 1 to 5 BaO 0 to 5 ZnO 1.0≦(MgO+CaO+SrO+BaO) / Al2O3<2 and 0 <MgO / (MgO+Ca+SrO+BaO)<0.5である。

[0076] In certain embodiments, the substantially alkali-free glass comprises, in mole percent on an oxide basis: 67-72 SiO2 11-14 Al2O3 0-3 B2O3 3 to 6 MgO 4 to 8 CaO 0-2 SrO 2 to 5 BaO 0-1 ZnO 1.0≦(MgO+CaO+SrO+BaO) / Al2O3<1.6 and 0.20 <MgO / (MgO+Ca+SrO+BaO)<0.40である。

[0077] In some embodiments, the glasses of the present disclosure include chemical fining agents. Such chemical fining agents include, but are not limited to, SnO2, As2O3, Sb2O3, F, Cl, and Br, and the concentration of the chemical fining agents is maintained at a level of 0.5 mol% or less. In some embodiments, the chemical fining agents include one or more of SnO2, As2O3, Sb2O3, F, Cl, or Br at a concentration of about 0.5 mol%, 0.45 mol%, 0.4 mol%, 0.35 mol%, 0.3 mol%, or 0.25 mol% or less. Chemical fining agents also include CeO2, Fe2O3, and other transition metal oxides, such as MnO2. These oxides may introduce color to the glass due to visible light absorption in one or more of their final valence states, and therefore their concentrations may be at a level of 0.2 mol% or less. In one or more embodiments, the glass composition includes one or more oxides of a transition metal at a concentration of about 0.2 mol%, 0.15 mol%, 0.1 mol%, or 0.05 mol% or less. In some embodiments, the glass composition includes about 0.01 mol% to about 0.4 mol% of any one or any combination of SnO2, As2O3, Sb2O3, F, Cl, and / or Br. In specific embodiments, the glass composition includes about 0.005 mol% to about 0.2 mol% of any one or any combination of Fe2O3, CeO2, and / or MnO2. In some embodiments, As2O3 and Sb2O3 constitute less than about 0.005 mol% of the glass composition.

[0078] In one embodiment, the exemplary glass is fabricated into sheet by a fusion process. The fusion draw process can produce a clean, flame-polished glass surface, which reduces surface-mediated distortion for high-resolution TFT backplanes and color filters. Figure 1 is a schematic diagram of a forming mandrel or isopipe in a non-limiting fusion process. Figure 2 is a schematic cross-sectional view of the isopipe near location 6 in Figure 1. Glass is introduced through inlet 1 and flows along the bottom of a trough 4 formed by weir walls 9 toward compression end 2. The glass overflows weir walls 9 on both sides of the isopipe (see Figure 2), and the two streams of glass join or fuse at base 10. Edge orienters 3 at both ends of the isopipe serve to cool the glass and produce relatively thick strips, called beads, at the edges. The beads are pulled by pulling rolls, allowing for sheet formation at high viscosities. By adjusting the speed at which the sheet is pulled from the isopipe, a very wide range of thicknesses can be produced using the fusion draw process at a fixed melt rate.

[0079] Downdraw sheet-draw fabrication processes, as well as the fusion process described in U.S. Patent Nos. 6,279,999 and 6,329,263 (both to Dockerty), which are incorporated herein by reference, can be used in this application. Without being bound by any particular theory of operation, it is believed that the fusion process can produce glass substrates that do not require polishing. Current glass substrate polishing can produce glass substrates with an average surface roughness of greater than about 0.5 nm (Ra) as measured by atomic force microscopy. Glass substrates produced by the fusion process have an average surface roughness of less than about 0.5 nm (Ra) as measured by atomic force microscopy. The substrates also have an average internal stress of 150 psi (1,034,214 Pa) or less as measured by optical retardation. It should be understood that the embodiments described herein are equally applicable to other forming processes, such as, but not limited to, float forming processes, and therefore the embodiments presented herein are not limited to the fusion process.

[0080] In one embodiment, the exemplary glasses are manufactured into sheets by a fusion process. While the exemplary glasses are compatible with the fusion process, the glasses of the present disclosure can also be manufactured into sheets or other products by different manufacturing processes. Such processes include slot draw, float, rolling, and other sheet-forming processes known to those skilled in the art.

[0081] In contrast to these alternative methods for forming sheets of glass, the fusion process, as described above, can produce extremely thin, extremely flat, and extremely uniform sheets with clean surfaces. While slot drawing can also produce clean surfaces, the dimensional uniformity and surface quality of slot-drawn glass are generally inferior to fusion-drawn glass due to changes in orifice shape over time, the accumulation of unstable debris at the orifice-glass interface, and the difficulty of forming an orifice to deliver perfectly flat glass. While the float process can deliver extremely large, uniform sheets, the surface is substantially marred by contact with the float bath on one side and exposure to condensed products from the float bath on the other. This means that float glass must be polished for use in high-performance display applications.

[0082] The fusion process often involves rapid cooling of the glass from a high temperature, which can result in a high fictive temperature, T f The fictive temperature can be thought of as representing the mismatch between the structural state of the glass and the state it would assume if fully relaxed at the temperature of interest. The glass transition temperature, T g The glass is then heated to a process temperature T p To, T p <T g ≦T f The reheating step to T may be affected by the viscosity of the glass. p <T g Therefore, the structural state of the glass is T pThe glass is out of equilibrium at T p The rate of this relaxation is T p The effective viscosity scales with the inverse of the glass's effective viscosity at T, such that high viscosity results in slower relaxation rates and low viscosity results in faster relaxation rates. The effective viscosity scales with the inverse of the glass's fictive temperature, such that low fictive temperatures result in higher viscosities and high fictive temperatures result in relatively lower viscosities. p The rate of relaxation at T increases or decreases depending on the fictive temperature of the glass. p Upon reheating to room temperature, this results in a relatively high relaxation rate.

[0083] T p One way to decrease the rate of relaxation at 1000 K is to increase the viscosity of the glass at that temperature. 13.2 represents the temperature at which a material has a viscosity in poise. As the temperature decreases below the annealing point, the viscosity of the supercooled melt increases. T g At a fixed temperature below T, a glass with a relatively high annealing point has a higher viscosity than a glass with a relatively low annealing point. p The viscosity of the substrate glass at 1000 K may increase. Generally, the compositional changes required to increase the annealing point also increase the viscosity at all other temperatures. In a non-limiting embodiment, the fictive temperature of glass produced by the fusion process is about 10 11 ~10 12 Corresponding to a viscosity in poise, and therefore an increase in the annealing point for a glass compatible with the fusion process, generally also increases its fictive temperature. For a given glass, regardless of the forming process, a relatively high fictive temperature, T g This results in a relatively low viscosity at temperatures below T, and thus increasing the fictive temperature counteracts the viscosity increase obtained by increasing the annealing point in the absence of an increase in the fictive temperature. pGenerally, a relatively large change in annealing point is required to obtain a significant change in relaxation rate at 785°C, or 790°C, or 795°C, or 800°C, or 805°C, or 810°C, or 815°C, or from about 796.1°C to about 818.3°C. Without being bound to any particular theory of operation, it is believed that such high annealing points result in acceptably low thermal relaxation rates during low temperature TFT processing, e.g., typical low temperature polysilicon rapid thermal annealing cycles.

[0084] In addition to the effect on the fictive temperature, increasing the annealing point also increases the temperature of the entire melting and forming system, particularly the isopipe. For example, Eagle XG glass and Lotus™ glass (Corning Incorporated, Corning, NY) have annealing points that differ by approximately 50°C, and their delivery temperatures to the isopipe also differ by 50°C. When held above 1310°C for extended periods, the zircon refractory from which the isopipe is formed exhibits thermal creep, which can be accelerated by the combined weight of the isopipe itself and the glass on the isopipe. A second exemplary glass embodiment has a delivery temperature of approximately 1350°C, or 1345°C, or 1340°C, or 1335°C, or 1330°C, or 1325°C, or 1320°C, or 1315°C, or 1310°C or less. Such delivery temperatures can extend the production regime without the need for isopipe replacement, or can extend the time between isopipe replacements.

[0085] During attempts to produce glasses with high annealing points and delivery temperatures below 1350°C and below 1310°C, it was found that the glasses exhibited a higher tendency to devitrify at the root of the isopipe and especially at the edge orienters relative to glasses with lower annealing points. Careful measurements of the temperature profile along the isopipe revealed that the edge orienter temperatures were much lower than expected relative to the center base temperature, which is believed to be due to radiative heat losses. The edge orienters are typically maintained at a temperature below the center base temperature to ensure that the glass has sufficient viscosity to maintain a flat shape as it leaves the base by placing the sheet between the edge orienters under tension. Because the edge orienters are located at both ends of the isopipe, they are difficult to heat, and the temperature difference between the center of the base and the edge orienters can be more than 50°C.

[0086] Without wishing to be bound by theory, it is believed that the increased tendency toward devitrification during the fusion process can be understood in terms of the radiative heat loss of the glass as a function of temperature. The fusion process is essentially isothermal, so the glass exits the inlet at a certain viscosity and the base at a much higher viscosity, but the actual viscosity values ​​are not significantly affected by the identity of the glass or the temperature of the process. Thus, glasses with relatively high annealing points generally require much higher isopipe temperatures than glasses with relatively low annealing points simply to match the delivery and exit viscosities. Figure 3 shows blackbody spectra corresponding to 1140°C and 1200°C, the approximate temperatures at the base of the isopipe (10 in Figure 2) for Eagle XG and Lotus glasses, respectively. The vertical line at approximately 2.5 mm corresponds roughly to the infrared cutoff, i.e., the beginning of the near-infrared region where the absorption of light in borosilicate glasses rises very steeply to a high, nearly constant value. At wavelengths shorter than the cutoff wavelength, glass has significant transmittance for wavelengths between 300 and 400 nm, a UV cutoff. From about 300 nm to about 2.5 mm, a 1200°C blackbody has a greater absolute energy and fraction of total energy than an 1140°C blackbody. Because glass is significantly transmissive throughout this wavelength range, the radiative heat loss from glass at 1200°C is much greater than the radiative heat loss from glass at 1140°C.

[0087] Again, without being bound to any particular theory of operation, it is believed that because radiative heat loss increases with temperature, and because high annealing point glasses are generally formed at higher temperatures than low annealing point glasses, the temperature difference between the center base and the edge orienter generally increases with the annealing point of the glass, which can directly relate to the tendency of the glass to form devitrification products on the isopipe or edge orienter.

[0088] The liquidus temperature of a glass is defined as the highest temperature at which a crystalline phase appears if the glass is held at that temperature indefinitely. The liquidus viscosity is the viscosity of the glass at the liquidus temperature. To completely avoid devitrification on the isopipe, it can be useful to make the liquidus viscosity high enough to ensure that no glass is present on the isopipe refractory or edge orienter material at or near the liquidus temperature.

[0089] In practice, only a few alkali-free glasses have liquidus viscosities of the desired magnitude. Experiments with substrate glasses suitable for amorphous silicon applications (e.g., Eagle XG glass) have shown that edge orienters can be continuously held at temperatures up to 60°C below the liquidus temperature of certain alkali-free glasses. While it was understood that glasses with higher annealing points would require higher forming temperatures, it was not anticipated that the edge orienters would be so cold relative to the center base temperature. A useful metric for keeping track of this effect is the ratio of the delivery temperature to the isopipe to the glass's liquidus temperature, T liq The fusion process involves heating the glass to 35,000 poise (T 35k ) is generally desirable. For a particular delivery temperature, T 35k -T liq It can be useful to make T as large as possible, but for amorphous silicon substrates such as Eagle XG glass, T 35k -T liq It has been found that an extended manufacturing regime is feasible if T is above about 80°C. 35k -T liq will also increase, so T 35k Regarding T above about 100°C 35k -T liq It can be useful to have T 35k -T liq The minimum useful value for varies approximately linearly with temperature from about 1200° C. to about 1320° C., which can be expressed according to equation (1).

[0090] Minimum T35k -T liq =0.25T 35k -225 (1) where all temperatures are in °C. Accordingly, one or more embodiments of exemplary glasses may have a glass temperature of >0.25T 35k T of -225°C 35k -T liq It has.

[0091] Additionally, the forming process may require a glass with a high liquidus viscosity. This is necessary to avoid devitrification products at the interface with the glass and to minimize visible devitrification products in the final glass. Thus, for a given glass that can be adapted for fusion processing to a particular sheet size and thickness, adjusting the process to produce wider or thicker sheets generally results in reduced temperatures at both ends of the isopipe. Some embodiments have a higher liquidus viscosity to provide greater flexibility for manufacturing by the fusion process. In some embodiments, the liquidus viscosity is 150 kP or greater.

[0092] In examining the relationship between liquidus viscosity and subsequent tendency for devitrification during the fusion process, the inventors surprisingly discovered that high delivery temperatures, such as those of the exemplary glasses, generally require higher liquidus viscosities for long-term production than typical AMLCD substrate compositions with lower annealing points. While not wishing to be bound by theory, this is believed to be due to the accelerated rate of crystal growth as the temperature increases. The fusion process is essentially an isoviscosity process, so at any fixed temperature, glasses with relatively high viscosity can be formed by the fusion process at higher temperatures than glasses with relatively low viscosity. While relatively low-temperature glasses can sustain some degree of undercooling (cooling below the liquidus temperature) for extended periods, because the rate of crystal growth increases with temperature, glasses with relatively high viscosity will grow equally unacceptable amounts of devitrification products in a shorter time than glasses with relatively low viscosity. Depending on where they are formed, devitrification products can compromise formation stability and can introduce visible defects into the final glass.

[0093] For formation in a fusion process, one or more embodiments of the glass compositions have a liquidus viscosity of about 150,000 poise, or 175,000 poise, or 200,000 poise or greater. A surprising result is that throughout the range of exemplary glasses, a sufficiently low liquidus temperature and a sufficiently high viscosity can be obtained to make the liquidus viscosity of the glass significantly higher than other compositions.

[0094] In the glass compositions described herein, SiO2 functions as a fundamental glass former. In certain embodiments, the SiO2 concentration can be greater than 60 mole percent to provide the glass with density and chemical resistance suitable for flat panel display glass (e.g., AMLCD glass) and a liquidus temperature (liquidus viscosity) that allows the glass to be formed by a downdraw process (e.g., a fusion process). Regarding the upper limit, the SiO2 concentration can generally be about 80 mole percent or less to allow the batch materials to be melted using conventional large-volume melting techniques, such as Joule melting in a refractory melter. As the SiO2 concentration increases, the 200 poise temperature (melting point) generally increases. In various applications, the SiO2 concentration is adjusted so that the glass composition has a melting point of 1750°C or less. In some embodiments, the SiO concentration is about 63.0 mol% to about 75.0 mol%, or about 63.0 mol% to about 71.0 mol%, or about 65.0 mol% to about 73 mol%, or about 67 mol% to 72 mol%, or about 68.0 to 72.0 mol%, or about 68.0 mol% to about 71.0 mol%, or about 68.0 mol% to about 70.5 mol%, or about 68.1 mol% to about 72.3 mol%, or about 68.5 to about 72.0 mol%, or about 68.95 mol% to about 71.12 mol%, or about 69.7 to about 71.7 mol%.

[0095] Al2O3 is another glass former used to make the glasses described herein. Al2O3 concentrations of 10 mole percent or greater provide the glass with a low liquidus temperature and high viscosity, which results in a high liquidus viscosity. Using at least 10 mole percent Al2O3 also improves the annealing point and Young's modulus of the glass. To achieve a ratio (MgO + CaO + SrO + BaO) / Al2O3 of 1.0 or greater, the Al2O3 concentration may be less than about 15 mole percent. In some embodiments, the Al2O3 concentration is about 11.0 to 14.0 mole percent, or about 11.0 to about 13.6 mole percent, or about 13.0 mole percent to about 14.5 mole percent, or about 13.0 mole percent to about 14.0 mole percent, or about 13.0 mole percent to about 14.18 mole percent. In some embodiments, the Al2O3 concentration is greater than or equal to about 9.5 mol%, 10.0 mol%, 10.5 mol%, 11.0 mol%, 11.5 mol%, 12.0 mol%, 12.5 mol%, or 13.0 mol%, while maintaining the ratio (MgO+CaO+SrO+BaO) / Al2O3 greater than or equal to about 1.0.

[0096] Some embodiments of the present disclosure have a Young's modulus of greater than about 81 GPa, or 81.5 GPa, or 82 GPa, or 82.5 GPa, or 83 GPa, or 83.5 GPa, or 84 GPa, or 84.5 GPa, or 85 GPa. In various embodiments, the aluminosilicate glass article has a Young's modulus of from about 81 GPa to about 88 GPa, or from about 81.5 GPa to about 85 GPa, or from about 82 GPa to about 84.5 GPa.

[0097] Some embodiments of the aluminosilicate glass article have a density of less than about 2.7 g / cc, or 2.65 g / cc, or 2.61 g / cc, or 2.6 g / cc, or 2.55 g / cc. In various embodiments, the density is from about 2.55 g / cc to about 2.65 g / cc, or from about 2.57 g / cc to about 2.626 g / cc.

[0098] B2O3 is both a glass former and a fluxing agent that aids in melting and lowers the melting point. B2O3 affects both the liquidus temperature and viscosity. Increasing the amount of B2O3 used can increase the liquidus viscosity of the glass. To achieve these effects, one or more embodiments of the glass composition have a B2O3 concentration of 0.1 mole percent or greater. As noted above with respect to SiO2, glass durability is critical for LCD applications. Durability can be controlled to some extent by increasing the concentration of alkaline earth oxides, and can be significantly reduced by increasing the B2O3 content. Because the annealing point decreases with increasing B2O3, it can be useful to maintain a low B2O3 content relative to the typical concentrations of B2O3 in amorphous silicon substrates. Thus, in some embodiments, the glass composition has a B2O3 concentration of about 0.0 to 3.0 mol percent, or greater than 0 to about 3.0 mol%, or about 0.0 to about 2.8 mol%, or greater than 0 to about 2.8 mol%, or about 0.0 to about 2.5 mol%, or greater than 0 to about 2.5 mol%, or about 0.0 to about 2.0 mol%, or greater than 0 to about 2.0 mol percent, or about 0.1 mol% to about 3.0 mol%, or about 0.75 mol% to about 2.13 mol%.

[0099] The Al2O3 and B2O3 concentrations are jointly selected to increase the annealing point, increase the Young's modulus, improve durability, reduce density, and reduce the coefficient of thermal expansion (CTE) while maintaining the melting and forming properties of the glass.

[0100] For example, increasing B2O3 and correspondingly decreasing Al2O3 can be useful for achieving low density and CTE, while increasing Al2O3 and correspondingly decreasing B2O3 can be useful for increasing the annealing point, Young's modulus, and durability, as long as the increase in Al2O3 does not reduce the ratio (MgO + CaO + SrO + BaO) / Al2O3 below about 1.0. For ratios of (MgO + CaO + SrO + BaO) / Al2O3 below about 1.0, it can be difficult or impossible to remove gas inclusions from the glass by post-melting of silica raw materials. Furthermore, when (MgO + CaO + SrO + BaO) / Al2O3 ≦1.05, mullite, an aluminosilicate crystal, can appear as a liquid phase. The presence of mullite as a liquid phase significantly increases the composition's sensitivity to liquid phases, and mullite devitrification products grow very quickly and are extremely difficult to remove once established. Thus, in some embodiments, the glass composition has a ratio (MgO+CaO+SrO+BaO) / Al2O3 of ≥ 1.0 (i.e., about 1.0 or greater). In various embodiments, the glass has a ratio (MgO+CaO+SrO+BaO) / Al2O3 of ≥ 1.05 (i.e., about 1.05 or greater), or between about 1 and about 1.17.

[0101] In one or more embodiments, the glass for use in AMLCD applications has a viscosity of about 28×10 -7 / ℃ ~ approx. 42×10 -7 / °C, or approximately 30 x 10 -7 / ℃ ~ approx. 40×10 -7 / °C, or approximately 32 x 10 -7 / ℃ ~ approx. 38×10 -7 / °C (22 to 300°C).

[0102] In addition to the glass formers (SiO, Al2O3, and B2O3), the glasses described herein also include alkaline earth oxides. In one embodiment, at least three alkaline earth oxides are part of the glass composition, for example, MgO, CaO, and BaO, and optionally SrO. The alkaline earth oxides provide the glass with various properties that are important for melting, fining, forming, and final use. Therefore, to improve the performance of the glass in these respects, in one embodiment, the (MgO + CaO + SrO + BaO) / Al2O3 ratio is about 1.0 or greater. As this ratio increases, the viscosity tends to increase more strongly than the liquidus temperature, and therefore the T 35k -T liq It becomes increasingly difficult to obtain suitably high values ​​for MgO+CaO+SrO+BaO. Thus, in another embodiment, the ratio (MgO+CaO+SrO+BaO) / Al2O3 is about 2 or less. In some embodiments, the ratio (MgO+CaO+SrO+BaO) / Al2O3 is about 1 to about 1.2, or about 1 to about 1.16, or about 1.1 to about 1.6. In particular embodiments, the ratio (MgO+CaO+SrO+BaO) / Al2O3 is less than about 1.7, or 1.6, or 1.5.

[0103] For certain embodiments of the present disclosure, alkaline earth oxides may be treated as if they were a single compositional component. This is because their effects on viscoelasticity, liquidus temperature, and liquidus phase relationships are more quantitatively comparable with each other than with the glass-forming oxides SiO, AlO, and BO. However, while the alkaline earth oxides CaO, SrO, and BaO can form feldspar minerals, particularly anorthite (CaAlSiO) and celsian (BaAlSiO), and their strontium-bearing solid solutions, MgO does not participate in these crystals to any significant extent. Thus, if feldspar crystals are already in the liquid phase, further addition of MgO can serve to stabilize the liquid relative to the crystals and thus lower the liquidus temperature. At the same time, the viscosity curve typically becomes steeper, reducing the melting point with little or no effect on low-temperature viscosity.

[0104] The inventors have discovered that the addition of small amounts of MgO can aid in melting at a reduced melting point, forming at a reduced liquidus temperature, and increased liquidus viscosity while retaining a high annealing point and associated low compaction. In various embodiments, the glass composition includes MgO in an amount from about 0.9 mol% to about 9 mol%, or from about 1.0 mol% to about 7.2 mol%, or from about 1.0 mol% to about 6.0 mol%, or from about 2.1 mol% to about 5.68 mol%, or from about 3.1 mol% to about 5.9 mol%, or from about 3.5 mol% to about 5.0 mol%.

[0105] The inventors have surprisingly found that suitable high values ​​of T 35k -T liq It has been discovered that glasses with a suitable high ratio of MgO to other alkaline earth elements, i.e., MgO / (MgO+CaO+SrO+BaO), fall within a relatively narrow range. As noted above, the addition of MgO can destabilize feldspar minerals, thereby stabilizing the liquid and lowering the liquidus temperature. However, once MgO reaches a certain level, the addition of mullite, i.e., Al6SiO2 13 The liquidus temperature may be increased and the liquidus viscosity may be stabilized, thereby increasing the liquidus temperature and decreasing the liquidus viscosity. Furthermore, high concentrations of MgO tend to decrease the viscosity of the liquid, thus ultimately decreasing the liquidus viscosity even if the liquidus viscosity remains unchanged with the addition of MgO. Thus, in another embodiment, 0.20≦MgO / (MgO+CaO+SrO+BaO)≦0.40, or in some embodiments, 0.22≦MgO / (MgO+CaO+SrO+BaO)≦0.37. Within these ranges, MgO can be varied relative to the glass formers and other alkaline earth oxides to achieve other desirable properties while still achieving the desired T. 35k -T liq can maximize the value of

[0106] Without being bound by any particular theory of operation, calcium oxide present in the glass composition can provide a low liquidus temperature (high liquidus viscosity), a high annealing point and Young's modulus, and a CTE in the most desirable range for flat panel applications, particularly AMLCD applications. The calcium oxide also contributes favorably to chemical resistance and is relatively inexpensive as a batch material compared to other alkaline earth oxides. However, at high concentrations, CaO increases density and CTE. Furthermore, CaO may stabilize anorthite, thus reducing liquidus viscosity, if the SiO concentration is sufficiently low. Thus, in one or more embodiments, the CaO concentration can be 4 mole percent or greater, or 4.0 mole percent. In various embodiments, the CaO concentration in the glass composition is from about 4.0 mol% to about 8.0 mol%, or from about 4.1 mol% to about 10 mol% (or 10.0 mol%), or from about 4.12 mol% to about 7.45 mol%, or from about 4.5 mol% to about 7.4 mol%, or from about 5.0 mol% to about 6.5 mol%, or from about 5.25 mol% to about 11 mol% (or 11.0 mol%), or from about 5.25 mol% to about 10 mol% (or 10.0 mol%), or from about 5.25 mol% to about 6.5 mol%, or from about 5.25 mol% to about 6.0 mol%.

[0107] Both SrO and BaO can contribute to a low liquidus temperature (high liquidus viscosity), and therefore the glasses described herein will typically contain at least both of these oxides. However, the concentrations of these oxides are selected to avoid increasing the CTE and density and decreasing the Young's modulus and annealing point. The relative proportions of SrO and BaO can be balanced to achieve a suitable combination of physical properties and liquidus viscosity that allow the glass to be formed by a downdraw process. In various embodiments, the glasses contain from about 0 to about 6.0 mol%, or greater than 0 to about 6.0 mol%, or from about 0 to about 4.5 mol%, 4.2 mol%, or 2.0 mol%, or greater than 0 to about 4.5 mol%, 4.2 mol%, or 2.0 mol%, or from about 0.45 mol% to about 4.15 mol% SrO. In some embodiments, the minimum amount of SrO is about 0.02 mol%. In one or more embodiments, the glass comprises from about 0 to about 4.5 mol%, or from greater than 0 to about 4.5 mol%, or from about 1.0 to about 9.0 mol%, or from about 1.2 mol% to about 4.4 mol%, or from about 2.42 mol% to about 4.3 mol%, or from about 2.5 mol% to about 4.5 mol%, or from about 2.6 mol% to about 4.4 mol%, or from about 3.0 mol% to about 5.4 mol%, or from about 3.5 mol% to about 4.0 mol% BaO.

[0108] To summarize the effects / roles of the core components of the glass of the present disclosure, SiO is the basic glass former. AlO and BO are also glass formers and can be selected as pairs; for example, increasing BO with a corresponding decrease in AlO can be used to obtain lower density and CTE, while increasing AlO with a corresponding decrease in BO can be used to obtain increased annealing point, Young's modulus, and durability, as long as the increase in AlO dosage does not reduce the RO / AlO ratio (where RO = (MgO + CaO + SrO + BaO)) below about 1.0. If the ratio is too small, a compromise is required in terms of meltability, i.e., the melting point becomes too high. Although BO can be used to reduce the melting point, high levels of BO require a compromise in the annealing point. In addition to considerations regarding meltability and annealing point, for AMLCD applications, the CTE of the glass must be matched to that of silicon. To achieve such a CTE value, exemplary glasses can control the RO content of the glass. For a given Al2O3 content, controlling the RO content corresponds to controlling the RO / Al2O3 ratio. In practice, RO / Al2O3 ratios less than about 1.6 produce glasses with suitable CTEs.

[0109] In addition to these considerations, the glass is preferably formable by a downdraw process, such as a fusion process, which means that the liquidus viscosity of the glass must be relatively high. Individual alkaline earths play an important role in this regard, as they can destabilize crystalline phases that would form in the absence of these alkaline earths. BaO and SrO are particularly effective in controlling liquidus viscosity and are included in the exemplary glasses for at least this purpose. As illustrated in the examples presented below, various combinations of alkaline earths produce glasses with high liquidus viscosities where the total amount of alkaline earths satisfies the R0 / Al2O3 ratio required to achieve a low melting point, high annealing point, and suitable CTE. In some embodiments, the liquidus viscosity is about 150 kP or greater.

[0110] In addition to the above-mentioned components, the glass compositions described herein can include various other oxides to adjust various physical, melting, fining, and forming attributes of the glass. Examples of such other oxides include, but are not limited to, TiO, MnO, FeO, ZnO, NbO, MoO, TaO, WO, YO, LaO, and CeO, as well as other rare earth oxides and phosphates. In one embodiment, the amount of each of these oxides can be 2.0 mole percent or less, and their combined concentration can be 5.0 mole percent or less. In some embodiments, the glass composition includes ZnO in an amount of about 0 to about 1.5 mole percent, or about 0 to about 1.0 mole percent. The glass compositions described herein may also include various contaminants, particularly FeO and ZrO, associated with batch materials and / or introduced into the glass by the melting, fining, and / or forming equipment used to produce the glass. The glass may also contain SnO2 as a result of Joule melting using tin-oxide electrodes and / or by batching with tin-containing materials such as SnO2, SnO, SnCO3, SnC2O2, and the like.

[0111] Although glass compositions are generally alkali-free, the glass may contain some alkali contaminants. For AMLCD applications, it is desirable to maintain alkali levels below 0.1 mole percent to avoid diffusion of alkali ions from the glass into the silicon of the thin film transistor (TFT), which could adversely affect TFT performance. As used herein, "alkali-free glass" is a glass having a total alkali concentration of 0.1 mole percent or less, where the total alkali concentration is the sum of the NaO, KO, and LiO concentrations. In one embodiment, the total alkali concentration is 0.1 mole percent or less.

[0112] As discussed above, a (MgO + CaO + SrO + BaO) / Al2O3 ratio of 1.0 or greater improves fining, i.e., the removal of gaseous inclusions from molten batch materials. This improvement allows for the use of more environmentally friendly fining packages. For example, the glass compositions described herein can have one or more or all of the following compositional characteristics, on an oxide basis: (i) an As2O3 concentration of up to 0.05 mole percent; (ii) an Sb2O3 concentration of up to 0.05 mole percent; (iii) an SnO2 concentration of up to 0.25 mole percent.

[0113] As2O3 is an effective high-temperature fining agent for AMLCD glasses, and in some embodiments described herein, As2O3 is used for fining due to its excellent fining properties. However, As2O3 is toxic and requires special handling during the glassmaking process. Therefore, in certain embodiments, fining is performed without significant amounts of As2O3, i.e., the finished glass has an As2O3 concentration of up to 0.05 mole percent. In one embodiment, As2O3 is intentionally not used in fining the glass. In such cases, the finished glass typically has an As2O3 concentration of up to 0.005 mole percent due to contaminants present in the batch materials and / or the equipment used to melt the batch materials.

[0114] While less toxic than As2O3, Sb2O3 is also toxic and requires special handling. Furthermore, Sb2O3 increases density, increases CTE, and decreases annealing point compared to glasses using As2O3 or SnO2 as fining agents. Thus, in certain embodiments, fining is performed without significant amounts of Sb2O3, i.e., the finished glass has an Sb2O3 concentration of up to 0.05 mole percent. In other embodiments, Sb2O3 is intentionally not used in fining the glass. In such cases, the finished glass typically has an Sb2O3 concentration of up to 0.005 mole percent due to contaminants present in the batch materials and / or the equipment used to melt the batch materials.

[0115] Although tin fining (i.e., SnO2 fining) is less effective than As2O3 and Sb2O3 fining, SnO2 is a common material with no known hazardous properties. Also, for many years, SnO2 has been a constituent of AMLCD glasses due to the use of tin oxide electrodes in Joule melting of batch materials for such glasses. The presence of SnO2 in AMLCD glasses has not caused any known adverse effects in the use of these glasses in the manufacture of liquid crystal displays. However, high concentrations of SnO2 are undesirable because they can lead to the formation of crystalline defects in the AMLCD glass. In one embodiment, the concentration of SnO2 in the finished glass is 0.25 mole percent or less.

[0116] Tin fining can be used alone or in combination with other fining techniques, if desired. For example, tin fining can be combined with halide fining, such as bromine fining. Other possible combinations include, but are not limited to, tin fining in combination with sulfate, sulfide, cerium oxide, mechanical bubbling, and / or vacuum fining. It is contemplated that these other fining techniques can be used alone. In certain embodiments, by maintaining the (MgO + CaO + SrO + BaO) / Al2O3 ratio and the concentrations of the individual alkaline earths within the ranges described above, the fining process becomes easier to perform and more effective.

[0117] The glasses described herein can be manufactured using a variety of techniques known in the art, hi one embodiment, the glasses are made using a downdraw process, such as, for example, a fusion downdraw process. In one embodiment, described herein is a method for producing alkali-free glass sheets by a downdraw process, comprising the steps of selecting, melting, and fining batch materials such that the glass comprising the sheets comprises SiO, AlO, BO, MgO, CaO, and BaO, and comprises, on an oxide basis: (i) a (MgO+CaO+SrO+BaO) / AlO ratio of 1:0 or greater; (ii) an MgO content of 3.0 mole percent or greater; (iii) a CaO content of 4.0 mole percent or greater; and (iv) a BaO content of 1.0 mole percent or greater, wherein: (a) the fining is carried out without significant amounts of arsenic (and optionally, without significant amounts of antimony); and (b) a collection of 50 consecutive glass sheets produced by the downdraw process from the melted and fined batch materials has average gas inclusions at a level of 0.10 gas inclusions per cubic centimeter, and each sheet in the collection has a volume of at least 500 cubic centimeters.

[0118] U.S. Patent No. 5,785,726 (Dorfeld et al.), U.S. Patent No. 6,128,924 (Bange et al.), U.S. Patent No. 5,824,127 (Bange et al.), and U.S. Patent Nos. 7,628,038 and 7,628,039 (De Angelis et al.) disclose processes for producing arsenic-free glasses. U.S. Patent No. 7,696,113 (Ellison) discloses a process for producing arsenic- and antimony-free glasses using iron and tin to minimize gas inclusions.

[0119] According to one embodiment, a collection of 50 consecutive glass sheets produced by a downdraw process from melted and fined batch material has an average gas inclusion level of less than 0.05 gas inclusions per cubic centimeter, and each sheet in the collection has a volume of at least 500 cubic centimeters.

[0120] The etch rate of a glass composition is a measure of how quickly material can be removed from glass, and it has been found that a fast etch rate provides value to panel manufacturers. The inventors have identified an "etch index" that allows for an estimation of the etch rate of a given glass composition in commercially relevant etching processes (such as, but not limited to, a 10-minute immersion in a 10% HF / 5% HCl solution at 30°C). The etch index is calculated using the following equation: Etching index = -54.6147 + (2.50004) * (Al2O3) + (1.3134) * (B2O3) + (1.84106) * (MgO) + (3.01223) * (CaO) + (3.7248) * (SrO) + (4.13149) * (BaO) (2) where the oxide is expressed as mole percent. In some embodiments, the etch index is greater than or equal to about 21. In various embodiments, the etch index is greater than or equal to about 21.5, 22, 22.5, 23, 23.5, 24, 24.5, 25, 25.5, 26, 26.5, 27, 27.5, 28, 28.5, 29, 29.5, 30, 30.5, or 31.

[0121] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.5~72.0 Al2O3 ≧13.0 B2O3 ≦2.5 1.0~6.0 MgO 4.0~8.0 CaO ≦4.5 SrO BaO≦4.5 Including, 1.0≦(MgO+CaO+SrO+BaO) / Al2O3≦1.6, Etching index ≥ 21; Annealing point ≥ 800°C; and The glass composition has a Young's modulus of >82 GPa.

[0122] One or more embodiments of the present disclosure comprise, in mole percent on an oxide basis: SiO2 63.0~71.0 13.0-14.0 Al2O3 >0~3.0 B2O3 0.9~9.0 MgO 5.25~6.5 CaO >0~6.0 SrO 1.0 to 9.0 BaO The present invention relates to a substantially alkali-free glass comprising:

[0123] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.0~71.0 13.0-14.0 Al2O3 >0~2.0 B2O3 3.5~5.0 MgO 5.25~6.5 CaO >0 to 2.0 SrO 2.5 to 4.5 BaO The present invention relates to a substantially alkali-free glass comprising:

[0124] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.0~70.5 13.0-14.0 Al2O3 >0~3.0 B2O3 0.9~9.0 MgO 5.25~11 CaO >0~6.0 SrO 1.0 to 9.0 BaO The present invention relates to a substantially alkali-free glass comprising:

[0125] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.0~70.5 13.0-14.0 Al2O3 >0~2.0 B2O3 3.5~5.0 MgO 5.25~10.0 CaO >0 to 2.0 SrO 2.5 to 4.5 BaO The present invention relates to a substantially alkali-free glass comprising:

[0126] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 63.0~75.0 13.0-14.0 Al2O3 >0~2.8 B2O3 0.9~9.0 MgO 5.25~11 CaO >0~6.0 SrO 1.0 to 9.0 BaO The present invention relates to a substantially alkali-free glass comprising:

[0127] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.0~72.0 13.0-14.0 Al2O3 >0~2.0 B2O3 3.5~5.0 MgO 5.25~10.0 CaO >0 to 2.0 SrO 2.5 to 4.5 BaO The present invention relates to a substantially alkali-free glass comprising:

[0128] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 63.0~75.0 13.0-14.0 Al2O3 >0~3.0 B2O3 0.9~9.0 MgO 5.25~11 CaO >0~6.0 SrO BaO 3.0-5.4 The present invention relates to a substantially alkali-free glass comprising:

[0129] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.0~72.0 13.0-14.0 Al2O3 >0~2.0 B2O3 3.5~5.0 MgO 5.25~10.0 CaO >0 to 2.0 SrO 2.5 to 4.5 BaO The present invention relates to a substantially alkali-free glass comprising:

[0130] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 63.0~75.0 13.0-14.5 Al2O3 >0~2.0 B2O3 0.9~9.0 MgO 5.0~6.5 CaO >0~6.0 SrO 1.0 to 9.0 BaO The present invention relates to a glass that is substantially alkali-free, comprising:

[0131] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.0~72.0 13.0-14.5 Al2O3 >0~2.0 B2O3 3.5~5.0 MgO 5.25~6.5 CaO >0 to 2.0 SrO 2.5 to 4.5 BaO The present invention relates to a substantially alkali-free glass comprising:

[0132] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 63.0~71.0 13.0-14.0 Al2O3 >0~2.0 B2O3 0.9~9.0 MgO 5.25~6.5 CaO >0~6.0 SrO 1.0 to 9.0 BaO The present invention relates to a substantially alkali-free glass comprising:

[0133] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.0~71.0 13.0-14.0 Al2O3 >0~2.0 B2O3 3.5~5.0 MgO 5.25~6.5 CaO >0 to 2.0 SrO 2.5 to 4.5 BaO The present invention relates to a substantially alkali-free glass comprising:

[0134] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 63.0~71.0 13.0-14.0 Al2O3 >0~2.0 B2O3 0.9~9.0 MgO 5.0~6.5 CaO >0~6.0 SrO 3.5-4.0 BaO The present invention relates to a substantially alkali-free glass comprising:

[0135] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.0~71.0 13.0-14.0 Al2O3 >0~2.0 B2O3 3.5~5.0 MgO 5.0~6.5 CaO >0 to 2.0 SrO 3.5-4.0 BaO The present invention relates to a substantially alkali-free glass comprising:

[0136] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 63.0~71.0 13.0-14.0 Al2O3 >0~2.0 B2O3 0.9~9.0 MgO 5.0~6.5 CaO >0~6.0 SrO 1.0 to 9.0 BaO wherein the sum of CaO and BaO is >8.6.

[0137] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: SiO2 68.0~71.0 13.0-14.0 Al2O3 >0~2.0 B2O3 3.5~5.0 MgO 5.0~6.5 CaO >0 to 2.0 SrO 2.5 to 4.5 BaO This applies to glass, including

[0138] One or more embodiments of the present disclosure may include: an annealing temperature of about 785°C or greater; a density of about 2.65 g / cc or less; a T of about 1750°C or less; 200P ; T below approximately 1340°C 35kP ; Young's modulus of about 82 GPa or more; and about 17.3 μm / mm in 10% HF / HCl 3 In a detailed embodiment, the glass has an annealing temperature of about 800°C or greater; a density of about 2.61 g / cc or less; a T of about 1700°C or less; and a glass that is substantially alkali-free and has an etch index of about 800°C or greater. 200P ; T below approximately 1310°C 35kP and about 18.5 μm / mm 3In some embodiments, the glass article has a T of about 1740°C, or 1730°C, or 1720°C, or 1710°C, or 1700°C, or 1690°C, 1680°C, 1670°C, 1660°C, or 1650°C. 200P In one or more embodiments, the glass article has a T of about 1640°C to about 1705°C, or about 1646°C to about 1702°C, or about 1650°C to about 1700°C. 200P It has.

[0139] One or more embodiments of the present disclosure may include: an annealing temperature of about 785°C or greater; a density of about 2.65 g / cc or less; a T of about 1750°C or less; 200P ; T below approximately 1340°C 35kP ; Young's modulus of about 82 GPa or more; or about 17.3 μm / mm in 10% HF / HCl 3 In some embodiments, the glass is substantially alkali-free and has one or more of the following etching indices: an annealing temperature of about 800°C or greater; a density of about 2.61 g / cc or less; a T of about 1700°C or less; 200P ; T below approximately 1310°C 35kP or about 18.5 μm / mm 3 The etching index is one or more of the above.

[0140] One or more embodiments of the present disclosure comprise, in mole percent on an oxide basis: SiO2 69.76~71.62 11.03~13.57 Al2O3 0 to 2.99 B2O3 3.15~5.84 MgO 4.55~7.35 CaO 0.2~1.99 SrO BaO 2.61~4.41 ZnO from 0 to 1.0

[0010] The present invention is directed to a substantially alkali-free glass comprising: a (MgO+CaO+SrO+BaO) / Al2O3 ratio of about 1.0 to 1.6, and a MgO / (MgO+CaO+SrO+BaO) ratio of about 0.22 to 0.37. In various embodiments, the glass has: a T(ann) of >785°C; a density of <2.65 g / cc; a T(ann) of <1750°C; 200P );<1340℃ T( 35kP ); Young's modulus >82 GPa; or an etching index >21.

[0141] Some embodiments of the present disclosure provide, on an oxide basis, mole percent: 68.14~72.29 SiO2 11.03~14.18 Al2O3 0 to 2.99 B2O3 1.09 to 7.2 MgO CaO 4.12~9.97 0.2~4.15 SrO BaO 1.26~4.41 ZnO from 0 to 1.0 wherein the ratio (MgO+CaO+SrO+BaO) / Al2O3 is about 1.0-1.6 and the ratio MgO / (MgO+CaO+SrO+BaO) is about 0.22-0.37. In various embodiments, the glass has: a T(ann) > 785°C; a density < 2.65 g / cc; a T(ann) < 1750°C 200P );<1340℃ T( 35kP ); Young's modulus >82 GPa; or >21 μm / mm 3 The etching index is one or more of:

[0142] One or more embodiments of the present disclosure are directed to a substantially alkali-free glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0-1.6 and a ratio MgO / (MgO+CaO+SrO+BaO) of about 0.22-0.37. In some embodiments, the glass has: a T(ann) > 785°C; a density < 2.65 g / cc; a T(ann) < 1750°C 200P );<1340℃ T( 35kP ); Young's modulus >82 GPa; or >21 μm / mm 3 In various embodiments, the glass comprises, in mole percent on an oxide basis, one or more of: SiO2 from 68.14 to 72.29; Al2O3 from 11.03 to 14.18; B2O3 from 0 to 2.99; MgO from 1.09 to 7.2; CaO from 4.12 to 9.97; SrO from 0.2 to 4.15; BaO from 1.26 to 4.41; and / or ZnO from 0 to 1.0.

[0143] Some embodiments are directed to a substantially alkali-free glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0-1.6 and a ratio MgO / (MgO+CaO+SrO+BaO) of about 0.22-0.37, the glass having a liquidus viscosity >150 kP. In various embodiments, the glass comprises, in mole percent on an oxide basis: one or more of: 68.14-72.29 SiO2; 11.03-14.18 Al2O3; 0-2.99 BO3; 1.09-7.2 MgO; 4.12-9.97 CaO; 0.2-4.15 SrO; 1.26-4.41 BaO; and / or 0-1.0 ZnO.

[0144] One or more embodiments provide a substantially alkali-free glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to 1.6, the glass having a 23 μm / mm 3The present invention relates to glasses having an etching index of 0.1 or greater, a T(ann) of >800°C, and a Young's modulus of >82 GPa. In various embodiments, the glasses include one or more of the following, in mole percent on an oxide basis: 68.14-72.29 SiO2; 11.03-14.18 Al2O3; 0-2.99 B2O3; 1.09-7.2 MgO; 4.12-9.97 CaO; 0.2-4.15 SrO; 1.26-4.41 BaO; and / or 0-1.0 ZnO.

[0145] Some embodiments of the present disclosure provide a substantially alkali-free aluminosilicate glass article, the glass article having: an annealing temperature of about 795°C or greater; a density of about 2.63 g / cc or less; a T of about 1730°C or less; 200P ; T below approximately 1320°C 35kP ; Young's modulus of about 81.5 GPa or more; and about 23 μm / mm 3 In various embodiments, the aluminosilicate glass article comprises one or more of: 68.5 to 72 mol% SiO2; 13 mol% or greater Al2O3; 0 to 2.5 mol% B2O3; 1 to 6 mol% MgO; 4 to 8 mol% CaO; 0 to 4.5 mol% SrO; 0 to 4.5 mol% BaO; and / or a ratio (MgO+CaO+SrO+BaO) / Al2O3 between 1 and 1.6.

[0146] Some embodiments of the present disclosure provide a substantially alkali-free aluminosilicate glass article, the glass article having: an annealing temperature of about 800°C or greater; a density of about 2.61 g / cc or less; a T of about 1710°C or less; 200P ; T below approximately 1310°C 35kP ; Young's modulus of about 81.2 GPa or more; and about 23 μm / mm 3In various embodiments, the aluminosilicate glass article comprises one or more of: 68.5 to 72 mol% SiO2; 13 mol% or greater Al2O3; 0 to 2.5 mol% B2O3; 1 to 6 mol% MgO; 4 to 8 mol% CaO; 0 to 4.5 mol% SrO; 0 to 4.5 mol% BaO; and / or a ratio (MgO+CaO+SrO+BaO) / Al2O3 between 1 and 1.6.

[0147] It will be understood that various embodiments of the present disclosure may involve specific features, elements, or steps that are described in connection with that particular embodiment. It will also be understood that certain features, elements, or steps, even though described in connection with one particular embodiment, may be interchangeable or combined with alternative embodiments in various non-illustrated combinations or permutations.

[0148] It should also be understood that as used herein, the terms "the," "a," and "an" mean "at least one" and are not limited to "only one," unless expressly stated otherwise.

[0149] Ranges can be expressed herein as from "about" one particular value, and / or to "about" another particular value. When such a range is expressed, examples include 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 aspect. 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.

[0150] As used herein, the terms "substantial," "substantially," and variations thereof are intended to note that a described characteristic is equal to or approximately equal to a value or description. Additionally, "substantially similar" is intended to indicate that two values ​​are equal or approximately equal. In some embodiments, "substantially similar" can refer to values ​​that are within about 10% of each other, e.g., within about 5% of each other, or within about 2% of each other.

[0151] Unless otherwise specified, it is not intended that any method described herein be construed as requiring that its steps be performed in a particular order. Thus, unless a method claim actually indicates the order in which its steps should be followed, or unless it is specifically stated in the claim or the description that the steps are limited to a particular order, no particular order is intended to be implied.

[0152] Where various features, elements, or steps of particular embodiments are disclosed using the transitional phrase "comprising," it is understood that alternative embodiments are also implicit, including those that may be described using the transitional phrase "consisting of" or "consisting essentially of." Thus, for example, implicit alternative embodiments to a device comprising A+B+C include embodiments in which the device consists of A+B+C and embodiments in which the device consists essentially of A+B+C.

[0153] It will be understood by those skilled in the art that various modifications and variations can be made to the present disclosure without departing from the spirit and scope of the present disclosure. Since those skilled in the art may conceive of combinations, subcombinations, and variations of modifications of the embodiments of the present disclosure that embody the spirit and substance of the present disclosure, the present disclosure shall be construed as including all within the scope of the appended claims and equivalents thereof. [Example]

[0154] The following examples are provided below to illustrate methods and results according to the presently disclosed subject matter. These examples are not intended to encompass all embodiments of the subject matter disclosed herein, but rather to illustrate representative methods and results. These examples are not intended to exclude equivalents and variations of the present disclosure that would be apparent to one skilled in the art.

[0155] While efforts have been made to ensure accuracy with respect to numbers (e.g., amounts, temperatures, etc.), some errors and deviations should be accounted for. Unless otherwise indicated, temperatures are in °C and are at ambient temperature, and pressures are at or near atmospheric. The compositions themselves are given in mole percent on an oxide basis and have been normalized to 100%. There are numerous variations and combinations of reaction conditions, such as component concentrations, temperatures, pressures, and other reaction ranges and conditions, which can be used to optimize the purity and yield of the products obtained from the processes described herein. Only reasonable and routine experimentation will be required to optimize such process conditions.

[0156] The glass properties listed in Table 1 were determined according to techniques conventionally used in the glass industry. Thus, the coefficient of linear thermal expansion (CTE) over the temperature range 25-300°C is 10 -7 The annealing point is expressed in °C and the strength is expressed in °C. These were determined by the fiber elongation technique (ASTM standards E228-85 and C336, respectively). 3 Densities, in m / s, were measured by the Archimedes method (ASTM C693). Melting points, in °C (defined as the temperature at which the glass melt exhibits a viscosity of 200 poise), were calculated using a fit of the Flucher equation to high-temperature viscosity data measured by a rotating cylinder viscometer (ASTM C965-81).

[0157] Liquidus temperatures, expressed in °C, were measured using the standard gradient boat liquidus method of ASTM C829-81. This involves placing crushed glass particles in a platinum boat, placing the boat in a furnace with a temperature gradient, heating the boat over the appropriate temperature range for 24 hours, and using microscopy to determine the highest temperature at which crystals are observed within the glass. More specifically, glass samples are removed from the single-piece Pt boat and examined using a polarized light microscope to identify the location and nature of crystals formed relative to the Pt / air interface and within the sample. Because the furnace gradient is quite well known, the temperature:location can be easily estimated within a range of 5-10 °C. The temperature at which crystals are observed in the inner portion of the sample is taken to represent the liquidus of the glass (for the corresponding test period). Tests are sometimes run for longer periods (e.g., 72 hours) to observe more slowly growing phases. Liquidus viscosity (poise) is determined from the liquidus temperature and the coefficients of the Fürcher equation.

[0158] The values ​​of Young's modulus, expressed in GPa, were determined using resonant ultrasonic spectroscopy of the general type described in ASTM E1875-00e1.

[0159] Exemplary glasses are shown in Table 1. As can be seen in Table 1, the exemplary glasses have densities, annealing points, and Young's moduli that make them suitable for display applications, such as AMLCD substrate applications, and more particularly for low-temperature polysilicon and oxide thin film transistor applications. Although not shown in Table 1, the glasses have durability to acidic and basic media similar to that available from commercially available AMLCD substrates, and are therefore suitable for AMLCD applications. The exemplary glasses can be formed using downdraw techniques and are compatible with the fusion process, particularly due to the criteria described above.

[0160] The exemplary glasses in Table 1 were prepared using commercially available sand as the silica source, crushed to 90% by weight through a US 100 mesh sieve. Alumina was the alumina source, periclase was the MgO source, limestone was the CaO source, strontium carbonate, strontium nitrate, or a mixture thereof was the SrO source, barium carbonate was the BaO source, and tin(IV) oxide was the SnO source. These raw materials were thoroughly mixed and loaded into a platinum vessel suspended in a furnace heated by a silicon carbide glow bar. They were melted and stirred at temperatures between 1600 and 1650°C for several hours to ensure homogeneity and delivered through an orifice at the bottom of the platinum vessel. The resulting glass chunks were annealed at or near the annealing point and then subjected to various experimental methods to determine their physical, viscous, and liquidus properties.

[0161] These methods are not exclusive and the glasses in Table 1 can be prepared using standard methods known to those skilled in the art, including continuous melting processes such as those practiced in continuous melting processes where the melter used is heated by gas, by electricity, or a combination thereof.

[0162] Suitable raw materials for making exemplary glasses include: commercially available sand as a source of SiO; alumina, aluminum hydroxide, hydrated forms of alumina, and various aluminosilicates, nitrates, and halides as sources of AlO; boric acid, boric anhydride, and diboron trioxide as sources of BO; periclase, dolomite (also a source of CaO), magnesia, magnesium carbonate, magnesium hydroxide, and various forms of magnesium silicates, aluminosilicates, nitrates, and halides as sources of MgO; limestone, aragonite, dolomite (also a source of MgO), wollastonite, and various forms of calcium silicates, aluminosilicates, nitrates, and halides as sources of CaO; and oxides, carbonates, nitrates, and halides of strontium and barium. If a chemical fining agent is required, tin can be added as SnO, as a mixed oxide with another major glass constituent (e.g., CaSnO), or under oxidizing conditions as SnO, tin oxalate, tin halides, or other compounds of tin known to those skilled in the art.

[0163] While the glasses in Table 1 contain SnO as a fining agent, other chemical fining agents can also be employed to obtain glasses of sufficient quality for TFT substrate applications. For example, exemplary glasses may employ any one or combination of AsO, SbO, CeO, FeO, and halides as intentional additions to promote fining, and any of these may be used in conjunction with the SnO chemical fining agent shown in the examples. Of these, AsO and SbO are generally recognized as hazardous materials and are controlled in waste streams, such as those that may be generated during glass manufacturing or TFT panel processing. Therefore, it is desirable to limit the concentrations of AsO and SbO individually or combined to 0.005 mol % or less.

[0164] In addition to the elements intentionally incorporated into the exemplary glasses, nearly every stable element in the periodic table is present in the glasses at some level, either through low-level contaminants in the raw materials, through high-temperature erosion of refractories and precious metals during the manufacturing process, or through intentional low-level introduction to fine-tune the properties of the final glass. For example, zirconium can be introduced as a contaminant through interaction with zirconium-rich refractories. As a further example, platinum and rhodium can be introduced through interaction with precious metals. As a further example, iron can be introduced as a trace element in the raw materials or intentionally added to enhance control of gas inclusions. As a further example, alkalis can be present as trace constituents at levels up to about 0.1 mole % relative to the combined concentration of LiO, NaO, and KO.

[0165] Hydrogen is inevitably present in the form of hydrogen anions, OH, and its presence can be confirmed by standard infrared spectroscopy. Dissolved hydroxyl ions have a significant, nonlinear effect on the annealing point of exemplary glasses, and therefore, it may be necessary to adjust the concentration of the major oxide constituents to compensate for the desired annealing point. Hydroxyl ion concentration can be controlled to some extent by the choice of raw materials or melting system. For example, boric acid is a major source of hydroxyl, and substituting boric acid with diboron trioxide can be a useful means for controlling the hydroxyl concentration in the final glass. The same reasoning applies to other potential raw materials, including compounds containing hydroxyl ions, hydroxides, or physisorbed or chemisorbed water molecules. When burners are used in the melting process, hydroxyl ions can also be introduced by combustion products from the combustion of natural gas and related hydrocarbons; therefore, it may be desirable to shift the energy used in melting from the burner to the electrode to compensate. Alternatively, an iterative process of adjusting the major oxide constituents to compensate for the deleterious effects of dissolved hydroxyl ions may be employed.

[0166] Sulfur can be present in natural gas and is also a trace constituent in many carbonate, nitrate, halide, and oxide raw materials. In the form of SO2, sulfur can be a troublesome source of gaseous inclusions. The tendency for SO2-rich defects to form can be managed to a large extent by controlling the sulfur level in the raw materials and by incorporating low levels of relatively reduced polyvalent cations in the glass matrix. Without wishing to be bound by theory, it is believed that SO2-rich gaseous inclusions are primarily due to the reduction of sulfuric acid (SO2) dissolved in the glass. 4~ The high barium concentration of the exemplary glasses is believed to increase sulfur retention in the glass early in melting, but as noted above, barium contributes to the low liquidus temperature and the associated high T 35k -T liq and is necessary to obtain high liquidus viscosity. Intentionally controlling the sulfur level in the raw materials to a low level is a useful means of reducing the sulfur dissolved in the glass (presumably as sulfuric acid). In particular, sulfur is preferably less than 200 ppm by weight in the batch materials, more preferably less than 100 ppm by weight in the batch materials.

[0167] Reduced polyvalent molecules can also be used to control the tendency of exemplary glasses to form SO2 bubbles. Without wishing to be bound by theory, these molecules behave as potential electron donors that suppress the electromotive force for sulfate reduction. Sulfate reduction is, in terms of half reactions:

[0168] [ka]

[0169] can be written as, where e - represents an electron. The "equilibrium constant" for this half-reaction is:

[0170] [ka]

[0171] where the square brackets represent chemical activity. Ideally, SO2, O2 and 2e - It is desirable to drive the above reaction to produce sulfuric acid from SO2. The addition of nitrates, peroxides, or other oxygen-rich raw materials can be beneficial, but this may also work against the reduction of sulfates early in the melt, which may counteract the primary benefit of adding them in the first place. SO2 has very low solubility in most glasses, making its addition to the glass melting process impractical. Electrons can be "donated" by reduced multivalent molecules, such as ferrous iron (Fe 2+ ) is the electron-donating half-reaction:

[0172] [ka]

[0173] It is expressed as follows.

[0174] This electron "activity" drives the sulfate reduction reaction to the left, releasing SO in the glass. 4~ Suitable reduced polyvalent molecules include Fe 2+ , Mn 2+ , Sn 2+ , Sb 3+ , As 3+ , V 3+ , Ti 3+ and others known to those skilled in the art. In each case, it can be important to minimize the concentration of these constituents to avoid adversely affecting the color of the glass, or in the case of As and Sb, to avoid adding these constituents at such high levels that they complicate waste management in the end user's process.

[0175] In addition to the major oxide components of the exemplary glasses and the minor or trace components mentioned above, halides may be present at various levels, either as contaminants introduced by raw material selection or as intentional components used to reduce gas inclusions in the glass. As fining agents, halides may be incorporated at levels of about 0.4 mol% or less, although it is generally desirable to use even smaller amounts, if possible, to avoid corrosion of off-gas handling equipment. In some embodiments, the concentration of individual halide molecules is less than about 200 ppm by weight for each individual halide molecule, or less than about 800 ppm by weight for the sum of all halide molecules.

[0176] In addition to these major oxide constituents, minor and trace constituents, polyvalent molecules, and halide fining agents, it may be useful to incorporate small concentrations of other colorless oxide constituents to achieve desired physical, optical, or viscoelastic properties. Such oxides include, but are not limited to, TiO2, ZrO2, HfO2, Nb2O5, Ta2O5, MoO3, WO3, ZnO, In2O3, Ga2O3, Bi2O3, GeO2, PbO, SeO3, TeO2, YO3, La2O3, Gd2O3, and others known to those skilled in the art. Through an iterative process of adjusting the relative ratios of the major oxide constituents of exemplary glasses, these colorless oxides can be incorporated at various temperatures, such as at the annealing point, T 35k -T liq Or up to about 2 mole percent can be added without unacceptably affecting the liquidus viscosity.

[0177] In one or more embodiments, glasses and glass articles are provided that exhibit reduced low-temperature stress relaxation and compaction compared to existing compositions. Glasses with low-temperature stress relaxation and compaction can provide glass articles for use in (e.g., display devices such as tablets or mobile phones) that exhibit improved total pitch variation during the manufacture of electronic devices utilizing the glass articles. Total pitch is the distance features move within a single glass sheet during processing of the glass sheet to produce an electronic device. Variation is the deviation from predictable motion between multiple glass sheets. Thus, "total pitch variation" is the distance display components on a glass sheet move during heating. The distance the display components move during heating must be aligned with the backside transistors during processing of the electronic device to produce a display; otherwise, the entire glass sheet must be scrapped. Smaller total pitch variation in a glass sheet results in better maintenance of the pitch variation coefficient. Unexpected motion due to unacceptably large total pitch variation can lead to yield loss of parts made from the glass sheet. If the amount that a glass sheet will displace during processing due to total pitch variation can be predicted, the motion for any new glass substrate can be accounted for in the manufacturing process of electronic devices utilizing glass sheets made from the glasses described herein. Lower total pitch variation results in higher resolution displays, brighter displays, and lower power consumption. For manufacturers of glass panels for display devices, this results in improved products due to higher resolution and lower power consumption, and reduced manufacturing costs due to higher yields and better etching performance. According to one or more embodiments, such glasses, when used in glass sheet form for the manufacture of display devices such as mobile phones and tablets, can maintain display performance and quality in both low-temperature and high-temperature processes.

[0178] According to one or more embodiments, the glasses disclosed herein can be used to produce glass articles in the form of glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, which can be incorporated into another article, such as an article having a display (i.e., a display article (e.g., consumer electronics including cell phones, tablets, computers, navigation systems, etc.), a building article, a transportation article (e.g., automobiles, trains, aircraft, ships, etc.), a consumer electronics article, or any article requiring some degree of transparency, scratch resistance, abrasion resistance, or a combination thereof). Examples of glass articles incorporating any of the coated glass-based articles disclosed herein include: Exemplary articles are shown in Figures 4A and 4B. Specifically, Figures 4A and 4B show a consumer electronic device 1900 that includes: a housing 1902 having a front surface 1904, a back surface 1906, and sides 1908; electrical components (not shown) at least partially or entirely within the housing, the electrical components including at least a controller, memory, and a display 1910 at or adjacent to the front surface of the housing; and a cover substrate 1912 at or on the front surface of the housing so as to cover the display. In some embodiments, the cover substrate 1912 may include any of the coated glass-based articles disclosed herein.

[0179] One or more embodiments of the present disclosure include: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm. The present invention provides a consumer electronic product, wherein the glass or glass sheet has an RO / (B2O3+Al2O3) of 0.5 to 1.1, 0.6 to 1.1, 0.7 to 1.1, 0.8 to 1.1, 0.5 to 1.05, 0.6 to 1.05, 0.7 to 1.05, 0.8 to 1.05, 0.5 to 1, 0.6 to 1, 0.7 to 1, or 0.8 to 1, where RO = (MgO+CaO+SrO+BaO). Such glass, glass article such as glass sheet, liquid crystal device including such glass sheet, and consumer electronic product including such glass sheet provide a relatively high resolution display and a relatively high brightness display.

[0180] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets are composed of SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO. BaO / RO is 0.22-1, 0.23-1, 0.25-1, 0.26-1, 0.22-0.9, 0.23-0.9, 0.25-0.9, 0.26-0.9, 0.22-0.8, 0.23-0.8, 0.25-0.8, 0.26-0.8, 0.22-0.7, 0.23-0.7, 0.25-0.7, 0.26-0.7, 0.22-0.6, 0.23-0.6, 0.25-0.6, 0.26-0.6, 0.22-0.5, 0.23-0.5, 0.25-0.5, or 0.26-0.5, where RO=(MgO+CaO+SrO+BaO). Such glass, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high resolution displays and relatively high brightness displays.

[0181] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets include SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, and wherein RO / (B2O3+Al2O3) is 0.5 to 1.1, 0.6 to 1.1, 0.7 to 1.1, 0.8 to 1.1, 0.5 to 1.05, 0.6 to 1.05 ... 0.7~1.05, 0.8~1.05, 0.5~1, 0.6~1, 0.7~1, or 0.8~1, where RO = (MgO + CaO + SrO + BaO) and BaO / RO is 0.22~1, 0.23~1, 0.25~1, 0.26~1, 0.22~0.9, 0.23~0.9, 0.25~0.9, 0.26~0.9, 0.22~0.8, 0.23~0 0.8, 0.25 to 0.8, 0.26 to 0.8, 0.22 to 0.7, 0.23 to 0.7, 0.25 to 0.7, 0.26 to 0.7, 0.22 to 0.6, 0.23 to 0.6, 0.25 to 0.6, 0.26 to 0.6, 0.22 to 0.5, 0.23 to 0.5, 0.25 to 0.5, or 0.26 to 0.5, where R0 = (MgO + CaO + SrO + BaO). Such glasses, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high resolution displays and relatively high brightness displays.

[0182] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets include SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, and have a Young's modulus / density (GPa / (g / cm 3 )) is 31 to 38, 32 to 38, 33 to 38, 31 to 37, 32 to 37, 33 to 37, 31 to 36, 32 to 36, 33 to 36, 31 to 35, 32 to 35, or 33 to 35. Such glass, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high-resolution displays and relatively high-brightness displays.

[0183] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets are selected from the group consisting of SiO2, B 2O3 and Al2O3, and BaO and at least one of MgO, CaO, and SrO, wherein RO / (B2O3+Al2O3) is 0.5 to 1.1, 0.6 to 1.1, 0.7 to 1.1, 0.8 to 1.1, 0.5 to 1.05, 0.6 to 1.05, 0.7 to 1.05, 0.8 to 1.05, 0.5 to 1, 0.6 to 1, 0.7 to 1, or 0.8 to 1, where RO=(MgO+CaO+SrO+BaO), and Young's modulus / density (GPa / (g / cm 3)) is 31 to 38, 32 to 38, 33 to 38, 31 to 37, 32 to 37, 33 to 37, 31 to 36, 32 to 36, 33 to 36, 31 to 35, 32 to 35, or 33 to 35. Such glass, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high-resolution displays and relatively high-brightness displays.

[0184] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets include SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, and the BaO / RO is 0.22~1, 0.23~1, 0.25~1, 0.26~1, 0.22~0.9, 0.23~0.9, 0.25~0.9, 0.26~0.9, 0.22~0.8, 0.23~0.8, 0.25~0.8, 0.26~0.8, 0.22~0.7, 0.23~0.7, 0.25~0.7, 0.26~0.7, 0.22~0.6, 0.23~0.6, 0.25~0.6, 0.26~0.6, 0.22~0.5, 0.23~0.5, 0.25~0.5, or 0.26~0.5, where RO = (MgO+CaO+SrO+BaO) and Young's modulus / density (GPa / (g / cm 3 )) is 31 to 38, 32 to 38, 33 to 38, 31 to 37, 32 to 37, 33 to 37, 31 to 36, 32 to 36, 33 to 36, 31 to 35, 32 to 35, or 33 to 35. Such glass, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high-resolution displays and relatively high-brightness displays.

[0185] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets include SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, and have a Young's modulus / density (GPa / (g / cm 3 )) is 31-38, 32-38, 33-38, 31-37, 32-37, 33-37, 31-36, 32-36, 33-36, 31-35, 32-35, or 33-35, and RO / (B2O3+Al2O3) is 0.5-1.1, 0.6-1.1, 0.7-1.1, 0.8-1.1, 0.5-1.05, 0.6-1.05, 0.7-1.05, 0.8-1.05, 0.5-1, 0.6-1, 0.7-1, or 0.8-1, where RO=(MgO+CaO+SrO+BaO) and BaO / RO is 0.22- 0.1, 0.23-1, 0.25-1, 0.26-1, 0.22-0.9, 0.23-0.9, 0.25-0.9, 0.26-0.9, 0.22-0.8, 0.23-0.8, 0.25-0.8, 0.26-0.8, 0.22-0.7, 0.23-0.7, 0.25-0.7, 0.26-0.7, 0.22-0.6, 0.23-0.6, 0.25-0.6, 0.26-0.6, 0.22-0.5, 0.23-0.5, 0.25-0.5, or 0.26-0.5, where RO=(MgO+CaO+SrO+BaO). Such glass, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high resolution displays and relatively high brightness displays.

[0186] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets are selected from the group consisting of SiO2, B2O3, and Al2O3. and BaO and at least one of MgO, CaO, and SrO, wherein RO / (BO+AlO) is 0.5-1.1, 0.6-1.1, 0.7-1.1, 0.8-1.1, 0.5-1.05, 0.6-1.05, 0.7-1.05, 0.8-1.05, 0.5-1, 0.6-1, 0.7-1, or 0.8-1, where RO=(MgO+CaO+SrO+BaO), and the annealing point is less than 790°C, less than 795°C, less than 800°C, or less than 805°C. Such glasses, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high resolution displays and relatively high brightness displays.

[0187] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets include SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, wherein BaO / RO is 0.22 to 1, 0.23~1, 0.25~1, 0.26~1, 0.22~0.9, 0.23~0.9, 0.25~0.9, 0.26~0.9, 0.22~0.8, 0.23~0.8, 0.25~0.8, 0.26~0.8, 0.22~0.7, 0.23~0.7, 0.25~0.7, 0.26~0.7, 0.22~ 0.6, 0.23 to 0.6, 0.25 to 0.6, 0.26 to 0.6, 0.22 to 0.5, 0.23 to 0.5, 0.25 to 0.5, or 0.26 to 0.5, where RO = (MgO + CaO + SrO + BaO) and the annealing point is less than 790° C., less than 795° C., less than 800° C., or less than 805° C. Such glasses, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high resolution displays and relatively high brightness displays.

[0188] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets include SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, and wherein RO / (B2O3+Al2O3) is 0.5 to 1.1, 0.6 to 1.1, 0.7 to 1.1, 0.8 to 1.1, 0.5 to 1.05, 0.6 to 1.05, 0.7 to 1.05, 0.8 to 1.05, 0.5 ~1, 0.6~1, 0.7~1, or 0.8~1, where RO = (MgO + CaO + SrO + BaO) and BaO / RO is 0.22~1, 0.23~1, 0.25~1, 0.26~1, 0.22~0.9, 0.23~0.9, 0.25~0.9, 0.26~0.9, 0.22~0.8, 0.23~0.8, 0.25~0.8, 0.26~0.8, 0.22~0.7, R O = (MgO + CaO + SrO + BaO), and the annealing point is less than 790° C., less than 795° C., less than 800° C., or less than 805° C. Such glasses, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high resolution displays and relatively high brightness displays.

[0189] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets include SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, and have a Young's modulus / density (GPa / (g / cm 3 )) is 31 to 38, 32 to 38, 33 to 38, 31 to 37, 32 to 37, 33 to 37, 31 to 36, 32 to 36, 33 to 36, 31 to 35, 32 to 35, or 33 to 35, and the annealing point is less than 790° C., less than 795° C., less than 800° C., or less than 805° C. Such glasses, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high-resolution displays and relatively high-brightness displays.

[0190] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets include SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, and the BaO / RO is 0.22~1, 0.23~1, 0.25~1, 0.26~1, 0.22~0.9, 0.23~0.9, 0.25~0.9, 0.26~0.9, 0.22~0.8, 0.23~0.8, 0.25~0.8, 0.26~0.8, 0.22~0.7, 0.23~0.7, 0.25~0.7, 0.26~0.7, 0.22~0.6, 0.23~0.6, 0.25~0.6, 0.26~0.6, 0.22~0.5, 0.23~0.5, 0.25~0.5, or 0.26~0.5, where RO = (MgO+CaO+SrO+BaO) and Young's modulus / density (GPa / (g / cm 3 )) is 31 to 38, 32 to 38, 33 to 38, 31 to 37, 32 to 37, 33 to 37, 31 to 36, 32 to 36, 33 to 36, 31 to 35, 32 to 35, or 33 to 35, and the annealing point is less than 790° C., less than 795° C., less than 800° C., or less than 805° C. Such glasses, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high-resolution displays and relatively high-brightness displays.

[0191] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets are selected from the group consisting of SiO2, B 2O3 and Al2O3, and BaO and at least one of MgO, CaO, and SrO, wherein RO / (B2O3+Al2O3) is 0.5 to 1.1, 0.6 to 1.1, 0.7 to 1.1, 0.8 to 1.1, 0.5 to 1.05, 0.6 to 1.05, 0.7 to 1.05, 0.8 to 1.05, 0.5 to 1, 0.6 to 1, 0.7 to 1, or 0.8 to 1, where RO=(MgO+CaO+SrO+BaO), and Young's modulus / density (GPa / (g / cm 3 ) is 31 to 38, 32 to 38, 33 to 38, 31 to 37, 32 to 37, 33 to 37, 31 to 36, 32 to 36, 33 to 36, 31 to 35, 32 to 35, or 33 to 35, and the annealing point is less than 790°C, less than 795°C, less than 800°C, or less than 805°C. Such glasses, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high-resolution displays and relatively high-brightness displays.

[0192] One or more embodiments of the present disclosure provide: glass; glass articles such as glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; liquid crystal display devices including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm; and consumer electronic products including glass sheets having a thickness of 0.1 mm to 3 mm, or 0.1 to 2 mm, or 0.1 to 1.5 mm, wherein the glass or the glass sheets include SiO2, B2O3, and Al2O3, and BaO and at least one of MgO, CaO, and SrO, and have a Young's modulus / density (GPa / (g / cm 3)) is 31-38, 32-38, 33-38, 31-37, 32-37, 33-37, 31-36, 32-36, 33-36, 31-35, 32-35, or 33-35, and RO / (B2O3+Al2O3) is 0.5-1.1, 0.6-1.1, 0.7-1.1, 0.8-1.1, 0.5-1.05, 0.6-1.05, 0.7-1.05, 0.8-1.05, 0.5-1, 0.6-1, 0.7-1, or 0.8-1, where RO=(MgO+CaO+SrO+BaO), and BaO / RO is 0.22-1, 0.23-1, 0.25-1, 0.26 0.22-0.6, 0.23-0.6, 0.25-0.6, 0.26-0.6, 0.22-0.5, 0.23-0.5, 0.25-0.5, or 0.26-0.5, where R O = (MgO + CaO + SrO + BaO), and the annealing point is less than 790°C, less than 795°C, less than 800°C, or less than 805°C. Such glass, glass articles such as glass sheets, liquid crystal devices including such glass sheets, and consumer electronic products including such glass sheets provide relatively high resolution displays and relatively high brightness displays.

[0193] Table 1 shows that T(ann)>795℃, Young's modulus>81.5, etching index>23, density<2.63, T( 200P ) < 1730 °C, and T( 35kP Table 2 shows further examples of glasses (samples 190-426) that approach the parameters of Table 1.

[0194] [Table 1-1]

[0195] [Table 1-2]

[0196]

Table 1-3

[0197]

Table 1-4

[0198]

Table 1-5

[0199]

Table 1-6

[0200]

Table 1-7

[0201]

Table 1-8

[0202]

Table 1-9

[0203]

Table 1-10

[0204]

Table 1-11

[0205]

Table 1-12

[0206]

Table 1-13

[0207]

Table 1-14

[0208]

Table 1-15

[0209]

Table 1-16

[0210]

Table 1-17

[0211]

Table 1-18

[0212]

Table 1-19

[0213]

Table 1-20

[0214]

Table 1-21

[0215]

Table 1-22

[0216]

Table 1-23

[0217]

Table 1-24

[0218]

Table 2-1

[0219]

Table 2-2

[0220]

Table 2-3

[0221]

Table 2-4

[0222]

Table 2-5

[0223]

Table 2-6

[0224]

Table 2-7

[0225]

Table 2-8

[0226]

Table 2-9

[0227]

Table 2-10

[0228]

Table 2-11

[0229]

Table 2-12

[0230]

Table 2-13

[0231]

Table 2-14

[0232]

Table 2-15

[0233]

Table 2-16

[0234]

Table 2-17

[0235]

Table 2-18

[0236]

Table 2-19

[0237]

Table 2-20

[0238]

Table 2-21

[0239]

Table 2-22

[0240]

Table 2-23

[0241]

Table 2-24

[0242]

Table 2-25

[0243]

Table 2-26

[0244]

Table 2-27

[0245]

Table 2-28

[0246]

Table 2-29

[0247] [Table 2-30]

[0248] Example 382 A study was conducted to determine the effect of Na2O content on stress relaxation. Glass samples containing glass with 260 ppm to 980 ppm Na2O by weight were collected for further testing. Na2O content was measured by inductively coupled plasma mass spectrometry. For Figures 5-7, data on Na2O content was normalized to 260 ppm as a baseline. Figure 5 is a graph showing normalized stress relaxation ratios at 30 minutes at 450°C, 550°C, and 650°C using a 260 ppm Na2O baseline. Higher Na2O concentrations increase stress relaxation at lower temperatures. Figure 6 is a graph showing normalized stress relaxation ratios relative to 260 ppm Na2O as a function of time at 550°C. Higher Na2O concentrations increase stress relaxation at shorter times than at longer times.

[0249] Figure 7 is a graph showing compaction at 500°C versus Na2O content for the 30 minute cycle. Higher Na2O concentrations dramatically increased compaction, especially in the low temperature test cycle.

[0250] Example 383 Samples with lower sodium contents, from 1 ppm to 259 ppm by weight of NaO, are analyzed in the same manner as in Example 382. The effect of lower NaO content on compaction, especially in the low temperature test cycle (LTTC), is observed to be consistent with Example 382.

[0251] Preferred embodiments of the present invention will be described below in detail.

[0252] Embodiment 1 The molar percentage of the oxides is such that (MgO+CaO+SrO+BaO) / Al2O3 is about 1.6 or less, and the molar percentage of the oxides is 68.5 to 72.0 SiO2, about 13.0 or more Al2O3, about 2.5 or less B2O3, 1.0 to 6.0 MgO, 4.0 to 8.0 CaO, about 4.5 or less SrO, and about 4.5 or less BaO. 3 a glass having an etching index of 1000 or greater, an annealing point of 1000 or greater, an Na2O content of 1 ppm to 259 ppm by weight, and a Young's modulus of 1000 or greater.

[0253] Embodiment 2 1. A glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-3.0 B2O3, 0.9-9.0 MgO, 5.25-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, said glass being substantially alkali-free and having a Na2O content of 1 ppm by weight to about 259 ppm by weight, and a SiO2 content of >21 μm / mm 3 The glass has an etching index of

[0254] Embodiment 3 3. The glass of embodiment 2, wherein the glass comprises, in mole percent on an oxide basis, 68.0-71.0 SiO2, >0-2.0 B2O3, 3.5-5.0 MgO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0255] Embodiment 4 1. A glass comprising, in mole percent on an oxide basis, 68.0-70.5 SiO2, 13.0-14.0 Al2O3, >0-3.0 B2O3, 0.9-9.0 MgO, 5.25-11 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, the glass being substantially alkali-free and having a Na2O content of 1 ppm by weight to about 259 ppm by weight and a SiO2 content of >21 μm / mm 3 The glass has an etching index of

[0256] Embodiment 5 5. The glass of embodiment 4, wherein the glass comprises, in mole percent on an oxide basis, >0-2.0 B2O3, 3.5-5.0 MgO, 5.25-10.0 CaO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0257] Embodiment 6 1. A glass comprising, in mole percent on an oxide basis, 63.0-75.0 SiO2, 13.0-14.0 Al2O3, >0-2.8 B2O3, 0.9-9.0 MgO, 5.25-11 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, said glass being substantially alkali-free and having a Na2O content of 1 ppm by weight to about 259 ppm by weight and a SiO2 content of >21 μm / mm 3 The glass has an etching index of

[0258] Embodiment 7 7. The glass of embodiment 6, wherein the glass comprises, in mole percent on an oxide basis, 68.0-72.0 SiO2, >0-2.0 B2O3, 3.5-5.0 MgO, 5.25-10.0 CaO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0259] Embodiment 8 1. A glass comprising, in mole percent on an oxide basis, 63.0-75.0 SiO2, 13.0-14.0 Al2O3, >0-3.0 B2O3, 0.9-9.0 MgO, 5.25-11 CaO, >0-6.0 SrO, and 3.0-5.4 BaO, said glass being substantially alkali-free and having a Na2O content of 1 ppm by weight to about 259 ppm by weight and a SiO2 content of >21 μm / mm 3 The glass has an etching index of

[0260] Embodiment 9 9. The glass of embodiment 8, wherein the glass comprises, in mole percent on an oxide basis, 68.0-72.0 SiO2, >0-2.0 B2O3, 3.5-5.0 MgO, 5.25-10.0 CaO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0261] Embodiment 10 1. A glass comprising, in mole percent on an oxide basis, 63.0-75.0 SiO2, 13.0-14.5 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.0-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, the glass being substantially alkali-free, having a Na2O content of 1 ppm to about 259 ppm by weight, a (MgO+CaO+SrO+BaO) / Al2O3 of 1.1-1.6, and a SiO2 content of >21 μm / mm 3 The glass has an etching index of

[0262] Embodiment 11 11. The glass of embodiment 10, wherein the glass comprises, in mole percent on an oxide basis, 68.0-72.0 SiO2, 3.5-5.0 MgO, 5.25-6.5 CaO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0263] Embodiment 12 1. A glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.25-6.5 CaO, >0-6.0 SrO, and 1.0-9.0 BaO, the glass being substantially alkali-free and having a Na2O content of 1 ppm by weight to about 259 ppm by weight and a SiO2 content of >21 μm / mm 3 The glass has an etching index of

[0264] Embodiment 13 13. The glass of embodiment 12, wherein the glass comprises, in mole percent on an oxide basis, 68.0-71.0 SiO2, 3.5-5.0 MgO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0265] Embodiment 14 1. A glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.0-6.5 CaO, >0-6.0 SrO, and 3.5-4.0 BaO, said glass being substantially alkali-free and having a Na2O content of 1 ppm by weight to about 259 ppm by weight and a SiO2 content of >21 μm / mm 3 The glass has an etching index of

[0266] Embodiment 15 15. The glass of embodiment 14, wherein the glass comprises, in mole percent on an oxide basis, 68.0-71.0 SiO2, 3.5-5.0 MgO, and >0-2.0 SrO.

[0267] Embodiment 16 1. A glass comprising, in mole percent on an oxide basis, 63.0-71.0 SiO2, 13.0-14.0 Al2O3, >0-2.0 B2O3, 0.9-9.0 MgO, 5.0-6.5 CaO, >0-6.0 SrO, 1.0-9.0 BaO, the sum of CaO and BaO >8.6, said glass being substantially alkali free and having a Na2O content of 1 ppm by weight to about 259 ppm by weight and a NaO content of >21 μm / mm 3 The glass has an etching index of

[0268] Embodiment 17 17. The glass of embodiment 16, wherein the glass comprises, in mole percent on an oxide basis, 68.0-71.0 SiO2, 3.5-5.0 MgO, >0-2.0 SrO, and 2.5-4.5 BaO.

[0269] Embodiment 18 Annealing temperatures above approximately 785°C; Density of approximately 2.65 g / cc or less; T below approximately 1750°C 200P ; T below approximately 1340°C 35kP ; A Young's modulus of approximately 82 GPa or greater; and 21 μm / mm defined by the formula: -54.6147+(2.50004)*(Al2O3)+(1.3134)*(B2O3)+(1.84106)*(MgO)+(3.01223)*(CaO)+(3.7248)*(SrO)+(4.13149)*(BaO) 3 Etching index above A glass having the formula: The glass is substantially alkali-free and has a Na2O content of 1 ppm by weight to about 259 ppm by weight.

[0270] Embodiment 19 19. The glass of embodiment 18, wherein the annealing temperature is about 800° C. or greater.

[0271] Embodiment 20 19. The glass of claim 18, wherein the density is less than or equal to about 2.61 g / cc.

[0272] Embodiment 21 Above T 200P 19. The glass of embodiment 18, wherein the t.s.

[0273] Embodiment 22 Above T 35kP 19. The glass of embodiment 18, wherein the t.s.

[0274] Embodiment 23 The etching index is approximately 21 μm / mm 3 19. The glass of embodiment 18.

[0275] Embodiment 24 19. The glass of claim 18, wherein the glass comprises, on an oxide basis, 68.1 to 72.3 mole percent SiO2.

[0276] Embodiment 25 19. The glass of embodiment 18, wherein the glass comprises, on an oxide basis, 11.0 to 14.0 mole percent Al2O3.

[0277] Embodiment 26 19. The glass of claim 18, wherein the glass comprises, on an oxide basis, B2O3 in mole percent >0-3.0.

[0278] Embodiment 27 19. The glass of embodiment 18, wherein the glass comprises, on an oxide basis, 1.0 to 7.2 mole percent MgO.

[0279] Embodiment 28 28. The glass of embodiment 27, wherein the glass comprises, on an oxide basis, 3.1 to 5.8 mole percent MgO.

[0280] Embodiment 29 19. The glass of embodiment 18, wherein the glass comprises, on an oxide basis, 4.1 to 10.0 mole percent CaO.

[0281] Embodiment 30 30. The glass of embodiment 29, wherein the glass comprises, on an oxide basis, 4.5 to 7.4 mole percent CaO.

[0282] Embodiment 31 19. The glass of embodiment 18, wherein the glass comprises, on an oxide basis, SrO in mole percent >0-4.2.

[0283] Embodiment 32 32. The glass of embodiment 31, wherein the glass comprises, on an oxide basis, SrO in mole percent >0-2.0.

[0284] Embodiment 33 19. The glass of embodiment 18, wherein the glass comprises, on an oxide basis, 1.2 to 4.4 mole percent BaO.

[0285] Embodiment 34 34. The glass of embodiment 33, wherein the glass comprises, on an oxide basis, 2.6 to 4.4 mole percent BaO.

[0286] Embodiment 35 19. The glass of embodiment 18, wherein the glass comprises, in mole percent on an oxide basis, 68.0 to 72.0 SiO2, 0.1 to 3.0 B2O3, and 5.0 to 6.5 CaO.

[0287] Embodiment 36 19. The glass of embodiment 18, wherein the glass comprises, in mole percent on an oxide basis, 13.0 to 14.0 Al2O3, 0.1 to 3.0 B2O3, and 5.25 to 6.0 CaO.

[0288] Embodiment 37 A substantially alkali-free glass comprising, on an oxide basis, 69.76 to 71.62 SiO2, 11.03 to 13.57 Al2O3, 0 to 2.99 B2O3, 3.15 to 5.84 MgO, 4.55 to 7.35 CaO, 0.2 to 1.99 SrO, 2.61 to 4.41 BaO, and 0 to 1.0 ZnO, wherein the ratio (MgO+CaO+SrO+BaO) / Al2O3 is about 1.0 to 1.6, the Na2O content is 1 ppm by weight to about 259 ppm by weight, and the ratio MgO / (MgO+CaO+SrO+BaO) is about 0.22 to 0.37.

[0289] Embodiment 38 1. A substantially alkali-free glass comprising, on an oxide basis, 68.14 to 72.29 SiO2, 11.03 to 14.18 Al2O3, 0 to 2.99 B2O3, 1.09 to 7.2 MgO, 4.12 to 9.97 CaO, 0.2 to 4.15 SrO, 1.26 to 4.41 BaO, and 0 to 1.0 ZnO, wherein the ratio (MgO+CaO+SrO+BaO) / Al2O3 is about 1.0 to 1.6, the Na2O content is 1 ppm by weight to about 259 ppm by weight, and the ratio MgO / (MgO+CaO+SrO+BaO) is about 0.22 to 0.37.

[0290] Embodiment 39 A substantially alkali-free glass, the ratio (MgO+CaO+SrO+BaO) / Al2O3 being about 1.0-1.6, the ratio MgO / (MgO+CaO+SrO+BaO) being about 0.22-0.37, T(ann)>785°C, density<2.65g / cc, T(200P)<1750°C, T(350)<1340°C, Young's modulus>82GPa, Na2O content from 1 ppm by weight to about 259 ppm by weight, and etching index>21μm / mm 3 That is, glass.

[0291] Embodiment 40 A substantially alkali-free glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0-1.6, a ratio MgO / (MgO+CaO+SrO+BaO) of about 0.22-0.37, a Na2O content of 1 ppm by weight to about 259 ppm by weight, and an etching index >21 μm / mm 3 That is, glass.

[0292] Embodiment 41 A substantially alkali-free glass, having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to 1.6, a ratio MgO / (MgO+CaO+SrO+BaO) of about 0.22 to 0.37, a Na2O content of 1 ppm by weight to about 259 ppm by weight, and a liquidus viscosity of >150 kP.

[0293] Embodiment 42 A glass that is substantially alkali-free, has a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to about 1.6, and an etching index of 21 μm / mm 3 or more, T(ann)>800°C, Na2O content is 1 ppm by weight to about 259 ppm by weight, and Young's modulus is >82 GPa.

[0294] Embodiment 43 1. A substantially alkali-free aluminosilicate glass article, comprising: The glass article is: Annealing temperatures above approximately 795°C; Density of approximately 2.63 g / cc or less; T below approximately 1730°C 200P ; T below approximately 1320°C 35kP ; Young's modulus of approximately 81.5 GPa or more; a NaO content of 1 ppm to about 259 ppm by weight; and Approximately 23μm / mm 3 Etching index above 1. An aluminosilicate glass article comprising:

[0295] Embodiment 44 1. A substantially alkali-free aluminosilicate glass article, comprising: The glass article is: Annealing temperatures above approximately 800°C; Density of approximately 2.61 g / cc or less; T below approximately 1710°C 200P ; T below approximately 1310°C 35kP ; Young's modulus of approximately 81.2 GPa or more; a NaO content of 1 ppm to about 259 ppm by weight; and Approximately 23μm / mm 3 Etching index above 1. An aluminosilicate glass article comprising:

[0296] Embodiment 45 T above approximately 1270°C 35kP ; a concentration of SnO2 of about 0.001 mol% to 0.5 mol%; a NaO content of 1 ppm to about 259 ppm by weight; and Approximately 21μm / mm 3 Etching index above Provided with glass.

[0297] Embodiment 46 The above glass has a T of approximately 1650°C or higher. 200P 46. ​​The glass of embodiment 45, comprising:

[0298] Embodiment 47 46. ​​The glass of embodiment 45, wherein the glass has a liquidus temperature of about 1150°C or greater.

[0299] Embodiment 48 The etching index is calculated by the formula: -54.6147+(2.50004)*(Al2O3)+(1.3134)*(B2O3)+(1.84106)*(MgO)+(3.01223)*(CaO)+(3.7248)*(SrO)+(4.13149)*(BaO) 46. ​​The glass of embodiment 45, defined by:

[0300] Embodiment 49 46. ​​The glass of embodiment 45, wherein the glass further comprises a Young's modulus of about 82 GPa or greater.

[0301] Embodiment 50 46. ​​The glass of embodiment 45, wherein the glass is substantially alkali-free.

[0302] Embodiment 51 T above approximately 1650°C 200P ; a concentration of SnO2 of about 0.001 mol% to 0.5 mol%; a NaO content of 1 ppm to about 259 ppm by weight; and Approximately 21μm / mm 3 Etching index above Provided with glass.

[0303] Embodiment 52 Liquidus temperature above about 1150°C; a concentration of SnO2 of about 0.001 mol% to 0.5 mol%; a NaO content of 1 ppm to about 259 ppm by weight; and Approximately 21μm / mm 3 Etching index above Provided with glass.

[0304] Embodiment 53 T above approximately 1270°C 35kP ; a NaO content of 1 ppm to about 259 ppm by weight; and SnO2 concentration of approximately 0.001 mol% to 0.5 mol% Provided with glass.

[0305] EMBODIMENT 54 The above glass has a T of approximately 1650°C or higher. 200P 54. The glass of embodiment 53, comprising:

[0306] Embodiment 55 54. The glass of claim 53, wherein the glass has a liquidus temperature of about 1150°C or greater.

[0307] Embodiment 56 54. The glass of embodiment 53, wherein the glass further comprises a Young's modulus of about 82 GPa or greater.

[0308] Embodiment 57 54. The glass of embodiment 53, wherein the glass is substantially alkali-free.

[0309] Embodiment 58 T above approximately 1650°C 200P ; a NaO content of 1 ppm to about 259 ppm by weight; and a concentration of SnO2 of about 0.001 mol% to 0.5 mol%; Provided with glass.

[0310] Embodiment 59 Annealing temperatures above approximately 785°C; Young's modulus of approximately 81 GPa or more; T below approximately 1750°C 200P ; T below approximately 1340°C 35kP ; a NaO content of 1 ppm to about 259 ppm by weight; and Average surface roughness measured by atomic force microscope of less than 0.5 nm Glass having

[0311] Embodiment 60 The above glasses have, on an oxide basis, mole percent: 60-80 SiO2; 5-20 Al2O3; 0-10 B2O3; 0-20 MgO; 0-20 CaO; 0-20 SrO; 0-20 BaO; and 0-20 ZnO 60. The glass of embodiment 59, comprising:

[0312] Embodiment 61 61. The glass of embodiment 59 or 60, wherein the density is about 2.7 g / cc or less and the specific modulus is less than about 34.

[0313] Embodiment 62 62. The glass according to embodiment 61, wherein the specific elastic modulus is 30 to 34.

[0314] Embodiment 63 61. The glass of embodiment 60, wherein the ratio (MgO+CaO+SrO+BaO) / Al2O3 is about 1.0 to 1.6.

[0315] EMBODIMENT 64 Above T 200P 60. The glass of embodiment 59, wherein the Tc is about 1700°C or less.

[0316] Embodiment 65 Above T 35kP 60. The glass of embodiment 59, wherein the t.s.

[0317] Embodiment 66 A glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to 1.6, a Na2O content of 1 ppm by weight to about 259 ppm by weight, T(ann)>785°C, a density<2.7 g / cc, T(200P)<1750°C, T(35kP)<1340°C, and a Young's modulus>81 GPa.

[0318] Embodiment 67 A glass having a ratio (MgO+CaO+SrO+BaO) / Al2O3 of about 1.0 to 1.6, T(ann) > 785°C, density < 2.7 g / cc, T(200P) < 1750°C, T(35kP) > 1270°C, Young's modulus > 81 GPa, and a Na2O content of 1 ppm by weight to about 259 ppm by weight.

[0319] Embodiment 68 The above glasses have, on an oxide basis, mole percent: 60-80 SiO2; 5-20 Al2O3; 0-10 B2O3; 0-20 MgO; 0-20 CaO; 0-20 SrO; 0-20 BaO; and 0-20 ZnO 68. The glass of embodiment 66 or 67, comprising:

[0320] Embodiment 69 68. The glass of embodiment 66 or 67, wherein the glass is substantially alkali-free.

[0321] Embodiment 70 68. The glass of embodiment 66 or 67, having a specific modulus of elasticity less than about 34.

[0322] Embodiment 71 71. The glass according to embodiment 70, wherein the specific elastic modulus is 30 to 34.

[0323] Embodiment 72 A liquid crystal display substrate comprising the glass of any one of embodiments 59 to 71.

[0324] Embodiment 73 A glass sheet comprising SiO2, B2O3, and Al2O3, and BaO, and at least one of MgO, CaO, and SrO, wherein RO / (B2O3+Al2O3) is 0.5 to 1.1, the Na2O content is 1 ppm by weight to about 259 ppm by weight, and BaO / RO is 0.22 to 1, where RO=(MgO+CaO+SrO+BaO). EMBODIMENT 74 74. The glass sheet of embodiment 73, comprising, on an oxide basis, 68.5 to 72.0 SiO, about 13.0 or more AlO, about 2.5 or less BO, 1.0 to 6.0 MgO, 4.0 to 8.0 CaO, about 4.5 or less SrO, and about 4.5 or less BaO, such that (MgO+CaO+SrO+BaO) / AlO is about 1.6 or less in mole percent.

[0325] Embodiment 75 a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component including at least a controller, a memory, and a display, the display being disposed on or adjacent to the front surface of the housing; and 74. The glass sheet of claim 73. 1. A consumer electronic product comprising:

[0326] Embodiment 76 a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component including at least a controller, a memory, and a display, the display being disposed on or adjacent to the front surface of the housing; and 75. The glass sheet of claim 74. 1. A consumer electronic product comprising:

[0327] Embodiment 77 Young's modulus / density (GPa / (g / cm)) is 31-38. 3 74. The glass sheet of claim 73, further comprising:

[0328] Embodiment 78 78. The glass sheet of embodiment 77, comprising, on an oxide basis, 68.5 to 72.0 SiO, about 13.0 or more AlO, about 2.5 or less BO, 1.0 to 6.0 MgO, 4.0 to 8.0 CaO, about 4.5 or less SrO, and about 4.5 or less BaO, such that (MgO+CaO+SrO+BaO) / AlO is about 1.6 or less in mole percent.

[0329] Embodiment 79 a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component including at least a controller, a memory, and a display, the display being disposed on or adjacent to the front surface of the housing; and 78. The glass sheet of claim 77. 1. A consumer electronic product comprising:

[0330] Embodiment 80 a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component including at least a controller, a memory, and a display, the display being disposed on or adjacent to the front surface of the housing; and 79. The glass sheet of claim 78. 1. A consumer electronic product comprising:

[0331] Embodiment 81 74. The glass sheet of embodiment 73, further having an annealing point that is less than 790°C.

[0332] Embodiment 82 82. The glass sheet of embodiment 81, comprising, on an oxide basis, 68.5-72.0 SiO, about 13.0 or more AlO, about 2.5 or less BO, 1.0-6.0 MgO, 4.0-8.0 CaO, about 4.5 or less SrO, and about 4.5 or less BaO, such that (MgO+CaO+SrO+BaO) / AlO is about 1.6 or less in mole percent.

[0333] Embodiment 83 a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component including at least a controller, a memory, and a display, the display being disposed on or adjacent to the front surface of the housing; and 82. The glass sheet of claim 81. 1. A consumer electronic product comprising:

[0334] Embodiment 84 a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component including at least a controller, a memory, and a display, the display being disposed on or adjacent to the front surface of the housing; and 83. The glass sheet of claim 82. 1. A consumer electronic product comprising:

[0335] Embodiment 85 78. The glass sheet of claim 77, further having an annealing point that is less than 790°C.

[0336] Embodiment 86 86. The glass sheet of embodiment 85, comprising, on an oxide basis, 68.5-72.0 SiO, about 13.0 or more AlO, about 2.5 or less BO, 1.0-6.0 MgO, 4.0-8.0 CaO, about 4.5 or less SrO, and about 4.5 or less BaO, such that (MgO+CaO+SrO+BaO) / AlO is about 1.6 or less in mole percent.

[0337] Embodiment 87 a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component including at least a controller, a memory, and a display, the display being disposed on or adjacent to the front surface of the housing; and 86. The glass sheet of claim 85. 1. A consumer electronic product comprising:

[0338] Embodiment 88 a housing having a front, a back, and a side; an electrical component at least partially within the housing, the electrical component including at least a controller, a memory, and a display, the display being disposed on or adjacent to the front surface of the housing; and 87. The glass sheet of claim 86. 1. A consumer electronic product comprising: [Explanation of symbols]

[0339] 1 entrance 2 Compression end 3 Edge Orienter 4 Trough 6 positions 9 Dam Wall 10 base 1900 Consumer Electronic Devices 1902 Housing 1904 Front 1906 Back 1908 Side 1910 display 1912 Cover Board

Claims

1. 1. A substantially alkali-free glass, comprising: In mole percent on an oxide basis, 68.5 to 72.0 SiO ２ , Al of 13.0 or more ２ O ３ , B below 2.5 ２ O ３ , MgO from 1.0 to 6.0, CaO from 4.0 to 8.0, SrO not exceeding 4.5, and BaO below 4.5 Including, Na ２ The O content is 1 ppm by weight to 259 ppm by weight, Ratio (MgO+CaO+SrO+BaO) / Al ２ O ３ is less than or equal to 1.6, Young's modulus >82 GPa; T(ann)>800°C, Glass with an etching index of 23 or greater.

2. Na ２ 2. The glass of claim 1, wherein the O content is from 1 ppm to 98 ppm by weight.

3. 1. A substantially alkali-free glass, comprising: In mole percent on an oxide basis, 63.0 to 71.0 SiO ２ , Al of 13.0 to 14.0 ２ O ３ , B: Over 0 to 3.0 ２ O ３ , MgO from 0.9 to 9.0, CaO from 5.25 to 6.5, SrO from greater than 0 to 6.0, and 1.0 to 9.0 BaO Including, Na ２ The O content is 1 ppm by weight to 259 ppm by weight, P ２ O ５ Not including, Glass with an etching index >21.

4. The glass comprises, on an oxide basis, mole percent: B between 0 and 2.0 ２ O ３ , and BaO from 3.0 to 5.4, The glass of claim 3 comprising at least one of:

5. 1. A substantially alkali-free glass, comprising: In mole percent on an oxide basis, 63.0 to 75.0 SiO ２ , Al of 13.0 to 14.0 ２ O ３ , Over 0 to 2.8 B ２ O ３ , MgO from 0.9 to 9.0, CaO from 5.25 to 11.0, SrO from greater than 0 to 6.0, and 1.0 to 9.0 BaO Including, Na ２ The O content is 1 ppm by weight to 259 ppm by weight, P ２ O ５ Not including, Glass with an etching index >21.

6. 1. A substantially alkali-free glass, comprising: In mole percent on an oxide basis, 63.0 to 75.0 SiO ２ , Al of 13.0 to 14.5 ２ O ３ , B: Over 0 to 3.0 ２ O ３ , MgO from 0.9 to 9.0, CaO from 4.0 to 11.0, SrO from greater than 0 to 6.0, and 1.0 to 9.0 BaO Including, Na ２ The O content is 1 ppm by weight to 259 ppm by weight, Ratio (MgO+CaO+SrO+BaO) / Al ２ O ３ is 1.0 to 1.6, Young's modulus >82 GPa; P ２ O ５ Not including, Glass with an etching index >21.

7. T(ann)>800°C, and T(35kP)>1270°C; The glass according to claim 6, which satisfies at least one of the following conditions:

8. T(ann)>785°C; 2.65 g / cm ３ has a density less than T(200P)<1750°C; T(35 kP)<1340°C; 7. The glass of claim 6, wherein the ratio MgO / (MgO+CaO+SrO+BaO) is between 0.22 and 0.

37.

9. The glass comprises, on an oxide basis, mole percent: B between 0 and 2.0 ２ O ３ , and 3.0 to 5.4 BaO The glass according to any one of claims 6 to 8, comprising at least one of:

10. Na ２ 9. The glass according to claim 6, wherein the O content is from 1 ppm to 98 ppm by weight.

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